Automatic Transmission Reseal
Joe Angell
First, some backstory:
About seven years go, I had my automatic transmission replaced due to it being burned out. The shop that did it noticed that the final drive/differential was overfilled and seemed to contain something that wasn’t gear oil. To save some money on the replacement, I kept the old differential and replaced only the gearbox part of the transmission.
After my engine failed and I replaced it with the 3.0L over a five and a half year period, I found that my transmission was leaking rather badly. After a few weeks of driving I’d get slipping when cold in first, and I’d a check of the the fluid levels shows that I was a quart and a half low on ATF. The leak appeared to be coming from the final drive portion of the transmission, like it was leaking through the seals of the output shaft, but the final drive and differential use gear oil, not transmission fluid, so that didn’t make sense.
Eventually, we correctly diagnosed the problem with some help from David T on DMCTalk.org. There is a tube — the converter shaft — that runs from the gearbox through the final drive and into the torque converter. The torque converter is filled with ATF, and this tube is how the ATF gets to it from the gearbox (the torque converter’s shaft also runs though the center of the tube). This tube has an O-rings on each end, and was sealed with the wrong type of sealant. This sealant dissolved in the ATF and caused the leak. ATF is thinner than gear oil, so it was sealing out of all of the seals in the final drive, as they weren’t designed for that.
Also, a quick note: don’t bother with florescent dye for gear oil leaks, since gear oil glows under UV light on its own. I added some to the ATF, but the entire bottom of the final drive glowed due to the mix of ATF and gear oil leaking out through the seals.
To fix it, I’d have remove the transmission from the car and take apart enough of it to repair the tube. I’d also want to check the state of the clutch packs, as I have certainly been running with it low on fluid and likely damaged some of them. For this job I enlisted my professional mechanic friend Dave. He really didn’t want to delve into the gearbox, as it often requires special tools that we don’t have, and precise alignments that we can’t do, but he reluctantly agreed to do what was possible as long as we stayed from the more fragile and alignment-sensitive parts.
Required Tools and Materials
Besides all the usual tools you’d use to work on a car, you’ll need the following:
Transmission jack, to safely lower the 150 pound transmission out of the car.
Gasket set for the Renault 4141. Gaskets are available from DeLorean dealers, Amazon and other retailers. Amazon even lists it as being for the DeLorean. There are two versions, the Master Kit and the Overhaul Kit. The difference is that the Master Kit also includes the clutch and brake packs, and thus is more expensive.
Permatex High-Tack Sealant/RTV, for the paper gaskets. Optional.
Permatex oil resistant sealant, such as Right Stuff, for sealing the other parts.
1 3/8” or 35mm wrench, to turn the engine by hand from the main crank pulley. A ratcheting box wrench is ideal.
Zip ties, to secure wiring and cables after the transmission is reinstalled.
Brake Cleaner, to clean off the transmission and other parts.
Output shaft seal, O-ring, roll pin, and possibly a shaft sleeve, one set per side, if you want to reseal the output shafts
Allen axle bolts, which are a lot easier to turn than the stock hex head bolts.
Removing the Transmission
Normally, I’d do this kind of thing in my garage. However, we’re in the process of tearing down the old one stall garage and building an oversized two stall one with its own lift and workshop, so I didn’t have that luxury. Dave was only available to help me while my garage was in transition, so we went to Gearhead in Warwick, Rhode Island. About 45 minutes from my house, they provide garage bay rentals at $20/hour (at the time of this writing), including all tools and a lift. It’s hard to beat the price. They’d also store the car for $50/week. The plan was to pull the transmission, leave the car there and bring the transmission home for repairs, then come back and re-install it.
I previously outlined how to remove the transmission with the engine, but I’ll go over it again here, since it’s a little different when you're taking it out on its own.
With the car on the ground:
Loosen the lug nuts on the passenger side rear tire. The tire has to come off to disconnect the emergency brake cable, as it crosses under the transmission.
Disconnect the plugs from the top of the transmission harness connector, or unplug the red bulkhead connector, depending on how much of the harness you want to remove with the transmission.
Pull the electrical connector for the transmission off of the bulkhead. It is pressed into a couple of rails, and can be pulled off by hand without any tools. Drop it down past the driver’s side of the engine, as it will be removed with the transmission.
Raise the car, and then:
Drain the transmission, using a square drive socket to remove the pan plug.
Drain the final drive, again with a square drive socket. Since my transmission was leaking into the final drive, the fluid was green transmission fluid, not the black-green gear oil it should have been.
Remove the axles (aka drive shafts). This requires a 17mm open end wrench for each of the 24 bolts. I’d suggest replacing them with allen head bolts, which are much easier to turn in the confined space. DeLoreanGo sells these. Since the car is in the air, the axle will turn as you try to break the bolts free, and the differential will override the fact that the car is in Park. I found that I could hold onto the tire with one arm while turning the wrench with the other to break the bolt free. I’d suggest removing five bolts from each end of the axle before removing the final bolt on each side so that it doesn’t fall unexpectedly.
Remove the passenger side rear tire.
Disconnect the emergency brake cable and run it back under the transmission and out of the way. For the Big Brakes system on my car, this meant using a 10mm socket to remove the brawl that holds the end of the cable, then pulling the cable itself out.
Disconnect the transmission cooler. I removed the forward line from the lower connection, and the rear line at the transmission. Both require a 18mm open ended wrench.
Disconnect the throttle linkage at the transmission. Rotate the mount back, then use a punch or screwdriver to push the cylindrical end out from the side, then lift the cable free. The cable stealth simple pulls out of the mount after that.
Remove the throttle cable bracket with an 11mm socket.
Remove the Hall sensor with a 13mm socket, which is an aftermarket addition to my car that acts as a digital speedometer pickup.
Disconnect the vacuum line from the transmission. You can do this from above, but I removed a hose clamp from the hard line from under the car with a 1/4” socket.
Unbolt the starter. This is a bit of a pain if you have an upgraded exhaust, since to remove the starter you have to remove the passenger side header. However, you can simply unbolt the starter without removing the header for the purposes of dropping the transmission. There are three bolts that require a 13mm socket with extensions.
Unbolt the dipstick bracket from the back of the transmission. I fabricated a custom mount for this, and attached it to the back of the head, and used an 11mm socket to remove it.
Unbolt the dipstick tube from the transmission, and remove the tube. You can probably remove the transmission without removing the tube, but you risk breaking it. An 11mm socket is used to remove that bolt.
Unbolt the transmission linkage with a 13mm socket. This is in the hole in the frame forwards of the transmission where the fuel accumulator sits. Be warned that on early cars the nuts on the back of the frame are not welded to the frame, and may unexpectedly turn on you and fall out when you try to take out the bolts. These nuts sit between the frame and body, making them very hard to reach. The last time I had to deal with this I fabricated a kind of wrench from sheet metal to hold the nuts while I removed the bolts, and then tapped a piece of aluminum to replace the nuts entirely. I was able to remove just one of the bolts this time, turning the bracket out of the way so that the linkage would drop free.
Unbolt the turnbuckle from the end of the linkage with a 13mm socket. This turnbuckle is reverses the direction of travel of the shifter, since these transmissions are usually mounted in the front of the car, not the back. Only the linkage to the transmission needs to be removed, and is held in place with a nylock nut.
Unbolt the torque converter from the flex plate. To do this, you’ll need a 35mm or 1 3/8”wrench to turn the engine clockwise by hand . A ratcheting box wrench makes this much easier. The bolts are accessible from the driver’s side of the engine, from behind the car. Make sure the engine is rotated such that the bolt has the most room around it or you may no the able to get the socket on it. You’ll need a long extension and a 17mm socket to reach them. Before unbolting, look through the access hole in the bell housing and mark both the torque converter and the flex plate with paint (you can get paint pens on Amazon or at any craft store), as you'll need to line them up again for re-installation.
Unbolt the coolant pipe bracket forwards of the transmission with a 10mm socket. The pipes need to be shifted slightly so that the transmission will clear them.
Position the transmission jack under the transmission, place it on a block of wood until it is level, and use a ratchet strap or chain to secure the transmission to the jack.
Unbolt the transmission mounts. The easiest thing to do here is to remove the mount themselves, unbolting them from the transmission and the frame. This requires a 13mm socket. One of the bolts was missing from one of my mounts, which may account for some of the excess vibration my car experiences. You may have to shift the transmission to the side a bit to get the mounts to drop free, as they are pretty tight in there.
Unbolt the bell housing from the engine. There are four bolts that require a 17mm flex socket and a long extension to break them free, although with some effort you can do it with a standard 17mm socket and wrench.
Draining the transmission fluid and final drive gear oil.
Removing the aftermarket allen head bolts from the axles.
Passenger side axle removed. The cap on the end of the axle stuck to the transmission, and easily pops off.
The disconnected transmission cooler, which requires an 18mm wrench. I disconnected the top line at the transmission, and the bottom line at the cooler.
Through the access hole in the bellhousing you can see the flex plate, torque converter, and the bolts that mate the two.
The three torque converter bolts are accessed from the back of the car with a long socket extension and a 17mm socket. Once aligned, go back to the access hole and add paint marks to the converter and flex plate so that you can find them and align them later.
The dipstick tube bracket needs to be disconnected from the cylinder head. The other end of the tube should also be disconnected to more easily remove the transmission. These both use an 11mm socket.
Disconnect the vacuum hose from the hard line. In my case this was a 1/4'“ socket for the hose clamp.
Transmission linkage bracket. I removed only the lower bolt with a 13mm socket, then swung the bracket up and moved the linkage out of the way. A nylock on the end of the cable attached to a turnbuckle further forward, and also needs to be removed to free the cable.
Removing the bracket that holds the coolant lines under the car is necessary to get enough room to lower the transmission.
The four bellhousing bolts, which require a 17mm socket, ideally a flex socket and a long extension for the top two bolts.
The transmission out of the car and sitting on my driveway back home.
At this point, the only thing holding the transmission up is the jack. Carefully lower the transmission, but you’ll need to watch for a few things as you do so:
The torque converter may stick to the engine output shaft. Use a pry bar between the converter and the engine through the access hole in the bell housing to break it free if needed. Note that the torque converter will still be filled with transmission fluid, and will likely leak if it is pulled out too far.
The bell housing might hit the engine cradle/subframe on the way down, and need to be shifted out of the way.
The linkage from the transmission is still going into the front of the frame. Be sure to draw it out as you go, and try not to bend it too far.
The coolant pipes forwards of the transmission will likely be in the way, and will need to be pulled and pushed so the transmission can clear them.
Make sure the electrical harness from above is coming down with the transmission and not hung up on anything.
Lower the transmission slowly and in stages, stopping often to check that you aren’t hung up on anything.
Once the transmission is out of the car, you can move it to your workbench. It weights about 150 pounds, so unless you have an assistant you’l likely want a hoist to lift it.
Disassembling the Transmission
We took apart a lot more of the transmission than we needed to. We could have resealed the just the converter shaft once we got to that plastic tube that carries ATF from the gearbox to the torque converter, but Dave wanted to reseal the system more completely, so we took apart as much as we could without touching anything that might require careful calibration or similar adjustments.
Torque Converter
Dave and I worked on the transmission in my basement. The first step was to remove the torque converter. It simply pulls out of the end of the transmission, with a shaft that runs the entire length of the transmission. You’ll likely spill some transmission fluid here. Set it aside.
BellHousing to Final Drive
A total of fourteen bolts are used to mate the bellhousing (aka “converter housing”) to the final drive (the manual says twelve, but there are fourteen). A 17mm socket can be used to remove them. Be sure to not which bolt goes where, as they come in three different lengths. Two of the bolts are outside of the housing; the rest are inside.
With all of the bolts out, the bellhousing can be pulled free from the final drive. You’ll likely need to the bellhousing with a mallet to separate them, and then possibly have to pry them apart with a pry bar. Expect more transmission fluid to leak out here.
You can now remove the paper gasket between the two parts.
The bolts for the bellhousing, positioned as they are installed. Note the different lengths of some of the bolts.
This angle better shows the different bolts lengths.
The two pieces separated, with the turbine shaft and plastic converter tube visible through the final drive.
Converter Shaft
At this point a mustard yellow plastic tube can be seen running the length of the final drive: the converter shaft. This is most likely where my leak was. The sealant — which wasn’t factory; there is no sealant in the original installation — was broken and failing. Dave suggested that it was the wrong kind of sealant, one not resistant to oil. The tube itself was in fine shape, which is good since it’s not easy to get one of those anymore. The O-rings seemed alright as well. You can remove this tube and set it aside.
The converter shaft, as shown in section G of the Workshop Manual.
The converter shaft is revealed once the final drive has been removed.
The sealant is worn and likely what is causing the leak.
Another view showing the worn sealant, but the tube itself is in good shape.
Pan Removal and Filter Inspection
The pan is held on with thirteen bolts, which come off with an 11mm socket. I just wanted to check on the filter, but also some governor parts come out from here, and the parking pawl is there, and son on. There was no visible debris in the filter — it was in very good shape. Mind you, I had removed the filter a few months prior, and found some minor debris, but nothing too significant. To really check, though, you have to cut the filter open, and since I didn’t have a replacement or the current interest in rebuilding the filter I did have, I left it as is.
The DPI silicone gasket was then cleaned in preparation for reinstalling later. While reusable, I had overtightened the pan a bit and deformed it, so I should probably get a new one if I have to take it off again.
After removing the pan, the filter and valve body are visible. The filter looks clean here, but to really tell you need to cut it open.
Computer Governor
The governor probably doesn’t have to come out, but it gets some things out of the way. There are detailed instructions with pictures on DMCTalk.org, which is what we followed.
Remove the governor computer from the side of the transmission via its two bolts with an 11mm socket.
Note that there is a shaft on the end of the governor spindly that extends into the transmission. Don’t lose this shaft.Remove the multiswitch connector, two bolts, 4mm allen wrench. I honestly have no idea what this does.
Remove the solenoid connector clip with a small screwdriver, then squeeze the .
Location of the governor on the transmission case.
Instructions on how to remove the electrical connections, from the Workshop Manual section G:07:03
A better view of the governor. The multidown switch connector is barely visible near the bottom right.
The inside end of the multiswitch. The O-ring on mine was damaged and needed to be replaced.
Removing the Gearbox Casing
To remove the casing that encloses the clutch packs, brakes, and other shifting components, the transmission needs to be stood on its end, with the forward (pump) part of the transmission facing up, and the final drive down. The catch is the turbine shaft that is sticking through the drive towards the torque converter, which sticks out quite a bit past the final drive housing. You can raise the transmission on boards to get enough clearance, but we opted to just drill a hole in my workbench. and stick the shaft through that.
Next, the transmission is put in park, which means pushing the linkage all the way in (aka down, with respect to the transmission sitting on its end). It can be easier to move it by turning the ratcheting piece by hand inside the transmission, which you can easily find while fiddling with the cable. The parking pawl clip then needs to be removed. If you don’t do these steps, you can’t actually lift the casing off of the transmission. You can now lift the casing off of the transmission.
There are ten bolts securing the final drive casing to the gearbox casing. a 13mm socket will get them out. One of the bolts has the nameplate on it as well. The paper seal between the two pieces can also be removed once the final drive is free from the gearbox.
The transmission stood on its end.
The turbine shaft can be seen running through the bottom of the table top via a hole I drilled in my workbench.
The “top” of the casing removed, with the old paper gasket still in place. This case protects the C1 and C2 clutches and planetary gear carrier, and contains the brown B1 brake disc (visible near the far end) and a piston mechanism, as well as housing the pump on the far end.
With the top of the casing off, the C2 clutch is clearly visible, as is the B2 brake pack.
Removing the Pump
The pump on the end of the transmission doesn’t need to be removed, but it’s easy to take off and there’s a seal in that there can be replaced. This uses an 11mm socket to remove the six bolts. The manual says to note the position of the gears on removal, although we left the gears where they were.
Starting to remove the six bolts holding the pump to the housing.
The removed pump housing.
REmoving the C2 Clutch
At this point the transmission looks some kind of sci fi prop, especially if you turn the larger cylinder on top. That’s the E2 clutch in the Renault manual, and the C2 clutch in the DeLorean manual. In French, “clutch” is “embrayage,” hence the different labeling. To remove it, simply lift it vertically upward. A small piece that looks like a ring with a cylindrical bit that extends up from the middle — the needle bearing — may have gotten stuck on the C2 clutch and fall out. It just rests on top of the smaller cylinder, the C1 clutch.
The C2 clutch is the large shiny cylinder sitting on top of the exposed gearbox, and simply flits off.
Removing the C1 Clutch
The C1 clutch is the smaller cylinder. Through the center of it is the turbine shaft, which is what runs through the final drive and the hole I made in the table. They are removed together as a single unit by just lifting them out. A thrust washer sits on top of the planetary gear carrier sitting underneath it.
The C2 clutch is the shorter cylinder that sits under and inside the C1 clutch, on top of the planetary gear carrier.
The clutch pack is just lifted out with the turbine shaft.
Brake B2 Disc Pack
Just below the C1 clutch is the B2 disc pack. This is an set of alternating steel discs and lined discs, topped with a wavy disc. These are again simply lifted up and out, making them by far the easiest pack to replace.
The top disc (which has three “teeth” on its outer edge) isn’t technically part of the pack, and in my case had some clear burn marks. It’s visibly warped, but that’s normal — it’s a “wavy disc” that provides tension. One of the steel discs in the pack also had some burn marks. The material on the clutch packs. It also suggested that we should check the other packs.
The complete B1 brake diss pack, consisting of alternating steel discs and discs coated with clutch material. On top is a wavy disc that provides pressure on the pack, and is reused when replacing the pack.
Burn marks on one my steel B1 discs (top) and the wavy disc (bottom), likely due to running low on transmission fluid as it leaked into the final drive.
Planetary Gear Housing
The last piece we removed was the planetary gear housing, which is held in with eight bolts using an 11mm socket. We replaced the paper seal under it with no sealant, re-installed the housing and torqued the bolts down to 2.3 meter decanewtons (m daN)
The planetary gear carrier.
The paper gasket under the carrier.
The underside of the carrier.
Replacing the Clutch and Brake Packs
There are a total of four sets of discs:
C1 clutches, which are in the C1 clutch assembly
C2 clutches, which are in the C2 clutch assembly
B1 brakes, which are in the outer casing of the gearbox
B2 brakes, which sit just below the C2 clutch assembly.
B2 Brake
The B2 brake pack is the simplest to get to, since they’re just sitting there. As mentioned above, mine were slightly burned and needed to be replaced. Simply pull out the old pack, and put in the new one.
Note that the topmost disc is a special wavy disc. It has three teeth on the outside edge, and is placed on top of the stack. We used Dr. Tranny’s Asemblee Goo between all discs when putting things back together. This both provides initial lubrication and lightly sticks the parts together during assembly.
C2 Clutch
The clutches inside the C2 assembly are fairly simple to get to. First flip it over so that the open side is up. You then use a screwdriver to remove the lock ring off of the top of the inner edge. You then simple pull out the remaining parts — distance sleeve, ring gear, etc — one at a time, until you’re down to the steel and lined clutch discs. A video showing how this comes apart can be found here, thanks to Martin L’s YouTube channel. He also removes the seal at the end, which we did not do.
Mine were in very good shape, which was surprising given the light wear and burns on the B2 brake pack. Some of the discs even had visible printed writing on them still, so clearly they weren’t very worn. We replaced them anyway, since they were already out.
C2 can be disassembled further, but this requires special tools (J-28867) and the parts that might be damaged in there are likely not available anyway. There are also seals inside that can be replaced, but they seemed fine, and we were primarily worried about the clutch pack, so we didn’t go any further.
The circlip on top comes off first.
The ring gear lifts out next.
Then the distance sleeve.
And finally the clutch pack. A wavy disc can be found under the steel and lined discs.
A new C2 disc (bottom) and an old one (top)
The old discs looked so good that some wiring was still visible on some of them.
The reassembled C2 clutch with new clutch packs. The green is Assemblee Goo, which was used to lubricate the parts as they were installed.
C1 Clutch
The C1 clutch pack is trickier to get to. The instructions say to remove the turbine shaft, but we did not want to deal with re-inserting it. At least that was the plan, until it fell out while we were handling it. It’s not hard to get back in — there’s a simple clip inside the C1 shaft, and the pack is just tapped back in with a brass hammer (or a hammer and a block of wood). Make sure this clip is locked onto the shaft.
To get to the clutch pack, you have to remove a lock ring, which requires special tool J-29351. We do not have that tool. Googling found that we could buy that tool, and we did indeed buy one (minus one of the “arms” that presses in on the ring). It is a more modern design made of plastic with pins on the ends of arms. Once positioned correctly, a plastic ring is pressed down over the arms, which preset them into the notches in the side of C1 and pops the retaining ring out.
We also went out and bought a 4” PVC pipe coupler from Home Depot so that we could build our own tool that was more similar to the original design shown in the manual. Our plan was to drill holes through the pipe to match the slots in C1, then insert small M2.3 x 10mm screws through them, tightening them in turn until we’d compressed the ring enough to remove it.
We were running low on time, and given how good the C2 clutch pack looked, we decided to not bother replacing the discs in here.
Tool J29351, as described in the Workshop Manual in section G:08:05.
A modern version of the same tool made of plastic. The outer ring slides off, and the tool is flipped over and placed on the top of the clutch, with the pins on the arms aligned with the slots in the side of the housing. The outer ring is then slid over the arms, pushing them in evenly and releasing the retaining ring.
B1 Brake
We thought this one would be easy, and with some difficulty removed the circlip directly above the discs. We then realized we couldn’t actually take them out of the casing without removing another set of rings above them. With much more difficulty we removed the outer circlip, and discovered that it was holding down a ring that covered a series of springs. At this point we decided this was way too much work and tried to reinstall the ring, but couldn’t get it to work. We finally looked at the manual, which we should have done in the first place, and noticed that this is where another special tool, J-28867, that we didn’t have. Another Martin L video shows a home made version of this tool in use.
We kludged this tool with a 6” diameter metal bucket from Home Depot. We had to unroll the rolled-over edge so that it didn’t interfere with the circlip, but it just fit. We put the transmission housing on some boards in my press, then placed a board across the bottom of the bucket and pressed down on it with the press until the springs were compressed. We were them able to lock the circlip into the slot. Note that this was not ideal: the tool in the manual shows that the compressor presses against the top of the springs and the ring just below them, not the bottom of the transmission housing, but it seemed to work without a problem and with no undue shifting of any other components.
If we had more time (or were braver), we could have removed that ring by fabricating another tool closer to J-28867, which is basically just a couple of blocks that get spun onto a long threaded rod, as can be seen in Martin L’s video here.
Removing the circlip that holds the springs in. DO NOT do this this way. You should compress the springs first, after which the clip is much easier to remove. We didn’t look at the manual, did it the wrong way, then realized we weren’t going to be able to easily reassemble it, and stoped before we went any further.
The ring almost snapped back into place, between the bucket and the inner edge of the casing.
The tool you’re supposed to use for this.
To compress the spring and get the circlip back in, we found a 6” bucket at Home Depot, deformed it slightly so that it fit on the spring carrier while leaving room for the circlip, then used the press to carefully compress the spring.
Keeping Organized
Here is every bolt removed from the transmission to get to this point. Normally I put the bolts into a case with yellow bins, but this time we just arranged them on a nearby table, labeling everything, although some of the labels are a bit off (“Other Ring Thing” is the planetary gear carrier, “Kickdown Switch Connector” is really for the multiswitch connector, “Main Connector Clip” is for the solenoid connector, and “Final Drive to Bellhousing” is “Final Drive to Gearbox Casing”), but we knew what we meant, and they’re arranged in order of disassembly. The rubber ring visible at the top is the old otterstat seal used in place of an O-ring for the dipstick tube.
Reassembly
This is really just the reverse of disassembly, but with new gaskets. There are three things to keep in mind:
Torque numbers. The numbers given in the Renault 4141 manual are in m daN, which is decanewton-meters. You’ll need to convert that to whatever your torque wrench uses. I found this site particularly useful. Just be sure to use the correct input units. The Workshop Manual section G:02:02 has a full set of torque numbers in newton-meters and foot-pounds.
Assemblée Goo. Use this when putting together the clutch pieces or any other parts that move freely and should be lubricated. This also makes them slightly stick together so that they don’t fall apart on you while you put everything together.
Gaskets. These are made of paper, and there are only a few gaskets that need to go back in. Dave used some high-tack sealant on them, simply spraying them down and letting them sit for a few minutes before putting them back into the transmission.
Workshop manual section G:02:02 containing the torque values for the transmission.
Torque values in decanewton-meters from the Renault 414 maul.
Planetary Gear Carrier
Dave used high-tack sealant on the gasket, then placed it on the final drive side of the gearbox before setting the carrier on top and torquing the eight bolts down. He then used a paint marker to indicate that they had been torqued.
B2 Discs
The B2 discs just slide into their slots. Follow the ordering shown in the Workshop manual, alternating steel and lined discs, with the wavy disc on top, and Assemblee Goo between each.
C2 Clutch and Turbine Shaft
The turbine shaft just needs to be tapped back into the C2 clutch. There is a retaining clip that looks like some straight clips or wires that are visible inside the shaft. Just use a brass mallet (or a hammer and a piece of wood, to avoid damaging the shaft) to tap the shaft until it latches onto the clip from below. It may take somewhat harder strikes than you expect to get it to latch in place.
C2 and the shaft then slide through the planetary gear carrier, and C2 rests on top of it.
C1 and the Gearbox Casing
This should be easy — slide the thrust washer and C1 onto C2, then place the casing over them both. We actually had a lot of trouble getting this to work. The B1 discs wouldn’t quite align with slots in C2 slots, and we’d wind up spinning them separately.
What we finally did was lay the two halves of the transmission on their bottom again, and insert C1 all the way into the gearbox casing, making sure it interlocks properly with the B1 discs. Once we put the case gasket on, one of us lifted the final drive with C2 mounted (making sure not to forget the thrust washer between C1 and C2), pushing it against C2 until it was properly mated. It was much easier to get C1 to slip over C2 this way, than to get C2 to line up with the B1 discs.
Once together, re-install the bolts to secure the gearbox case to the final drive. You can also reinstall the parking pawl and clip now that the two cases are realigned.
The new gasket for the planetary gear carrier being test fit on the final drive, before being sprayed with high-tack sealant.
The carrier, clutches and brakes reinstalled.
Another view, which also clearly shows the carrier bolts marked with paint after being torqued. The case outer seal is also placed and ready for installation.
A view of the B2 brakes, visible edge-on under the C1 and C2 clutches in the planetary gear carrier, and packed with Assemblee Goo.
Bolting the final drive and the gearbox housings together.
Reinstalling the Governor
The governor itself simply bolts onto the side of the transmission. We used some Permatex oil-resistant sealant (aka “RTV”, although we didn’t happen to use Right Stuff here, but something similar also by Permatex) to make sure it didn’t leak. We missed an important detail, however: at one point, the governor fell on the floor, and the shaft popped off. This shaft tells the computer how fast the car is going, and without it the transmission won't shift — it will think you’re just revving the engine with your foot on the brake. Make sure this piece is there before you mount it.
The multiswtich connector just bolts in place. We replaced the O-ring and again used Permatex sealant here.
The tricky one is the solenoids switch. Again we replaced the O-rings and used sealant to avoid leaks. It just clips into place, but actually getting it to clip can be a bit of a pain. We eventually got it, though.
The somewhat difficult to secure clip for the solenoids.
Bellhousing
Before mounting the bellhousing, we decided to replace the torque converter seal. This is straight forward: you tap out the old one, then tap in a new one. Getting it out was easier when we removed a separate interior piece first, which is held on by four bolts. With that clear, the old one could be more easily tapped out with a hammer. The new one was then tapped the new one in with a piece of wood and a hammer until it was flush. It’s pretty much the same as installing a rear or front main seal on an engine.
Before replacing the interior piece, we put in a new gasket and then torqued it down properly as per the Workshop Manual.
Finally, the bellhousing is bolted to the final drive, with a gasket in between. We started bolting it together and realized we forgot to put the converter shaft back in — the part that was leaking, and the whole reason we took it apart in the first place. We quickly removed the bolts, put new O-rings on the plastic tube, smeared a light layer of oil-resistant Permatex sealant around it just to be sure, and then resumed bolting the bellhousing back on.
Remember that the bolts are different lengths. Be sure to put the bolts back in the way they came out.
Removing an inner piece that sits behind the seal.
Tapping in the new seal with a piece of wood to avoid damaging anything.
The final installed seal.
At this point, everything is back together and ready to be re-installed into the car.
Reinstallation
Once we got the transmission back to Gearhead, we lifted it up onto the transmission jack, strapping it down with a chain. We then slid the torque converter into the end, and got ready to lift it. All you need to do is get the transmission in the right place so you can bolt it up. Mostly you raise it, making sure the linkage goes into the hole in the frame and that you clear the coolant pipes. You also need to make sure that the bellhousing doesn’t get caught on the subframe. The jack has leveling controls that allow you to tilt it on two axes, which is useful since you probably didn’t put it perfectly flatly on the jack head. We also used a tall jack stand under the pan at one point, which allowed us more flexibility in tipping it forwards and backwards by simply raising and lowering the jack.
Once it’s pretty much aligned, you can try to get one of the bolts through the bellhousing and into the engine block. From there you can get a second one in, and so on until all four are loosely in place. At one point we put the jack stand under the engine and used that t title the engine forwards slightly to align the bolt holes, rather than tilting the transmission.
Next is the transmission mounts. We left the frame side and transmission side mated, and installed them together onto the frame and transmission. Five of the bolts on each side aren’t hard to get in, but the sixth one is in exactly the wrong position. It took us over an hour to get those back in. Maybe it would have been easier if we separated them, but we eventually go tit.
With the bellhousing bolts and transmission mount bolts in place, we finally torqued them down.
The transmission on the jack, ready to install.
The jack most of the way up.
Another view getting it into position.
Dave tightening the bellhousing bolts to the engine with a long extension.
Torque Converter
This is where those paint marks you made on the flex plate and torque converter come into play. The flex plate should already be in the right position, since you probably didn’t turn the engine since you unbolted the converter. Now you just need to rotate the converter by hand by reaching up through the access hole and turning it with your fingers. Once you’ve lined up the paint marks, you can go back behind the car with your long extension and socket and insert the first bolt.
This bolt went in surprisingly easy for me, and was lined up on the first try. You need to get it in most of the way, but not tight, as the other mounting holes on the converter aren’t lined up with the flex plate yet. If you don’t put it in far enough, the bolt heads will get held up on the block when you try to rotate the engine.
The other two bolts were a bit harder to line up, but it didn’t take us too long to get them in place. Some poking at the converter from the access hole, or a pick through the bolt holes in the flex plate and converter got the job done.
Filling the Final Drive
The final drive takes a bit under two quarts of gear oil. I used Lucas 80w 90, which seems to be a popular weight for the DeLorean’s automatic transmission. It’s slightly easier to do this before putting back on the axle.
Filling is done by removing the plug on the side of the final drive, then pouring the oil in. The fill line is the very bottom of the plug hole, so once it starts coming out of there you know you’re done. Let it drain for a bit, then put the plug back in.
Transmission Cooler
The cooler lines just reattach to the transmission and the cooler itself. While tinkering with the angle of the line to reduce kinking, I completely forgot to torque down the nut at the top of the cooler, and we leaked transmission fluid until we fixed that.
Shift Linkage
The transmission linkage is again secured to the bracket inside the fuel accumulator access hole in the frame. The end of the cable is hooked back onto the turnbuckle and is held in place with a nylock.
Vacuum Line
The vacuum line needs to be reconnected. We had previously replaced the short hose between the transmission and the hardline due to some slightly damage to it, so now we just had to reattach the hardline itself and connect the other end of it to the line coming off the engine.
Starter
Since I have headers on my exhaust, the starter as a bit of a pain to get back in. You need to get the shim(s) in place between the starter and transmission, then hold it up with one hand as best you can get it in there while you fit the bolts in the starter. The only way I could do this was with a pry bar under the starter to both raise and level it against the transmission. It took probably twenty minutes to get the bolts in, in part because one of the bolts just didn’t want to get past the shim.
Emergency Brake Cable
The parking brake cable is run back under the transmission and reattached to the brake caliper. Once in place, it clips into the nots under the transmission casing to keep it from dragging.
Throttle Cable
The throttle cable end goes back on the arm on the governor, which is a bit easier if you use a punch or screwdriver to get it all the way in. Mine had a bit of slack in it, which we were able to tighten from the engine bay. The cable sheath was then secured to the transmission body again.
We also noticed that the cable was sticking slightly. Dave quickly found the problem: the cable had rested on the exhaust header and burned through the sheath, and then twisted just enough to cause a kink. For the time being we removed the kink and zip-tied it to the frame to keep it from burning on the header again. I’ll be replacing that cable in the future.
Dipstick Tube
The dipstick tube is another thing that caused us some trouble. We had to drop the pan a few times and go through a few otterstat seals to get it to work. We used used a scrubbing pad to remove the old RTV from the hole and dipstick tube, and installed the new seal with Permatex Right Stuff. We had problems with it popping out, so while it set we used a bolt with a large washer to act as a weight, sometimes attaching vice grips to the bottom of the bolt for more weight. At one point we used a heat gun to speed up the curing process. We then added Right Stuff to the end of the dipstick tube before inserting it into the seal and bolting it to both the transmission and the engine.
Eventually we noticed that the tube wasn’t sitting properly upright in the hole, mostly due to the bracket being slightly bent. This was causing the dipstick to tear the seal, as well as it not being aligned properly and deforming the seal. Once we fixed that, it sealed and no longer leaked. Note that it’s not perfectly vertical, but rather slightly angled.
Using an otterstat seal in place of an O-ring for the dipstick tube.
To try to keep the seal from popping out on us, we used a bolt, and a large washer as a weight, and then vice grips to ad more weight. This worked fairly well.
Axles
The axles just bolt up as before. I used the allen head bolts from DeLoreanGo, which are much easier than working with a wrench. For one, with an 8mm bit driver I could use a power screwdriver to get them most of the way in. Just remember to put those shims (or whatever they’re called) between the bolts and the axles. I also had to put my hall sensor gear back on for the driver’s side axle at the output shaft.
To get enough torque to tighten the bolts, you’ll need to use a longer handle on your average 8mm Allen wrench. We just used a socket extension and a socket that we could fit the end of the wrench into. This worked just fine, and got the bolts tight.
Coolant Bracket
Once the transmission is past the coolant pipes, the bracket that holds the pipes under the core can be bolted down.
The fill hole for the final drive is just forward of the driver’s side output shaft. Fill it until oil starts seeping out from the hole.
One of the axles installed with allen head bolts.
A stack of extensions and an 8mm Allen wrench to get enough torque to tighten the axle bolts.
The coolant pipe bracket can be reinstalled once the transmission is in place. Here it is still loose from when we stored the car without the transmission.
Shifting Problems
Besides the leaking dipstick tube and forgetting to tighten the top nut on the cooler, we had one problems shifting. Specifically, we were stuck in first gear.
We dropped the pan again to check the shift solenoids. As best we could tell, they were frozen. This video from Martin L is a pretty good guide to what should happen: the ball at the end should spin freely until power is applied, at which point they lock in place as the solenoid engages. You can use the diagnostic port on the transmission harness from the engine bay to see what the governor has them set to, which is described in significant detail here. In short, the solenoids have 12v applied to both wires when they’re off, and one of the wires is switched to ground when it needs to be on. When in first, the switched pin on both solenoids are grounded, at which point the balls should be locked in place.
The good news is that balls on both solenoids they were locked in place. The bad news is that we couldn’t get them unlocked. We removed the solenoids from the car (a single bolt holds them both, and they simply pop once released) and used a car battery to directly power the solenoids. We tried a PowerProbe first, but we think it just can’t sink enough current for them. We also tried tapping them with a hammer and dousing them in brake cleaner, but we couldn’t get them to spin.
We finally put them in a bath of Free All penetrant overnight, and in the morning we were able to freely turn the balls with no power applied. We have no idea how they get seized — they’d only been out of the car for a week — but this seemed to fix it.
We put them back in the car, but still only had first and second. Running out of ideas, we decided to pull the governor and bring it home to bench test . With the governor out we noticed that the shaft was missing, which turned out to be because it was sitting on the floor in my basement. This shaft is how the governor knows what speed the car is moving at, and without it it thinks that driver is just revving the engine with their foot on the brake. Once we reinstalled it, the car properly shifted. As you can imagine, this whole thing was quite annoying.
The solenoids are visible in the right in this picture, with the harness going to the top of left.
The solenoids on the bench for testing, after being bathed in a penetrant bath to loosen them up.
The governor with the input shaft missing.
The input shaft properly installed, ready to go back into the transmission.
Output Shaft Leak
There was one final problem to deal with: test driving showed a leak on the driver’s side output shaft. I’d previously replaced the seal, but not the O-ring. Our best guess is that the transmission fluid overpressure chose the O-ring behind this shaft as the weakest point and leaked the mix of gear oil and transmission fluid out through here.
You have to be very careful removing the differential adjustment nut. If you over-tighten it, you’ll burn out the differential. Under-tightening is equally bad (although I admit I don’t know how, exactly). This means you need to count the exact number of turns out, and the make the same number of turns back in.
We marked the transmission case with paint markers at first, but they got wiped away by the leaking gear oil. So we grabbed a punch and made two small marks on the transmission case, then two more on the nut. Before removing the nut, the bolt holding the key-shaped lock needs to be removed with an 11mm socket, after which the nut can spin freely by hand. When taking off the nut, we made sure to count, the number of turns (nine, in my case) until it was removed. We then simply popped out the old O-ring, put in the new one, and spun it back on the same number of turns, lining up the punched marks at the end, and reinstalled the lock.
We went for another test drive, and no more leaks. As in, nothing at all is leaking, anywhere. Success!
A punch was used to make two marks on the transmission body, and two more on the adjustment nut. This was to ensure that we got the nut exactly back where it needs to be.
With the nut out, the O-ring on the side can be replaced with a new one.
Final Result
It has been a week since the transmission was resealed, and it’s working very well. There are literally no leaks at all in it, which is very rare for a DeLorean automatic transmission. There are definitely some other things I can test, like getting a new filter, doing a line pressure test to verify vacuum pressure, a new throttle cable that doesn’t have a burned sheath, and so on. Dave also noticed some seeping oil from my engine covers, but it was nothing critical. Save for a very slight hesitation (but not a slip) when shifting from first to second (and which I think was there previously), the reseal went pretty much perfectly in the end.