Clutch/Trans/Rear Seal issues -- Early VIN, 10-spline car

[Project Vixen]

I am trying to help a friend out with an early VIN car. He had a leaking rear main seal, so we pulled the transmission as part of the repair. While the transmission was out, he had it rebuilt and also ordered a new clutch, clutch fork, pilot bearing, throwout bearing, bleeder extension hose, shifter bushings and more from DeLorean Go. I helped with the transmission removal, while my friend and a couple of others did the reinstallation of the rear main, clutch and trans.


On the initial reassembly, they realized he needed the 10-spline not the 21-spline items, so he re-ordered the correct parts. He needed a new fork as well, and told me the original was not available, but he said DGo assured him that the newer fork would work (though I do see that they stock the early version on their site so I'm not so sure). He also ordered a pilot tool for the 10-spline (and he said he also got the early style throwout bearing). He replaced the rear main seal (which still seems to be leaking, which is another issue -- I'm not sure if they used the 'right stuff' sealant or only the paper gasket). I understand they had a hard time getting the trans and motor to click together, and he said they had to use the bolts to 'pull' the trans up snug with the block, with a medium amount of force. I'm not liking that last part -- sounds like something was off alignment or the like.


Well... here's where it gets interesting. I believe the clutch cylinder and lines are pretty well bled. There is a nice firm (actually very firm) pedal, and I can see a good amount of movement from the pin on the back of the slave cylinder when actuating the clutch, and at the clutch itself. We had a bit of trouble shifting through the gears at first, but once the cable was adjusted again it will now shift 1-5 & reverse just fine... but only with the engine turned off. It won't go into ANY gear with the engine running.


Getting more interesting... we lifted it off of the back wheels so both were free. In neutral, either wheel spins either direction without affecting the other. In gear, turning one wheel makes the other revolve in the opposite direction. These are what I would expect. Now since shifting into gear with the engine running wasn't possible, we shifted into 1st with it off, pressed in the clutch, and started the car. When letting out the clutch, neither wheel turns... they just kind of 'shudder'. I would have thought something still needs bled in the clutch lines, except air in the lines wouldn't cause the clutch not to grab at all. I would think it would be the opposite -- the clutch would have issues releasing, not engaging.


One guess is that possibly that new style fork isn't compatible, causing a preload of force on the clutch, which might have been what necessitated 'pulling' the trans/motor together with the bolts, so the clutch might be effectively now 'pressed in' without even touching the pedal. Seeing if the clutch is spinning when in gear with the motor running might help, though I don't want to get under it then (but two phones with facetime makes a great inspection camera!)

So... any guesses as to what was missed, or what is wrong? Any and all help is appreciated!

[David T]

It is going to have to come apart again. Hopefully you will see the problem and be able to fix it. Sometimes the fork pops out of place while you are assembling. If you can't see anything obvious the next step is to take a pile of parts to a brake/clutch shop and have them look it over and maybe take some measurements and make it work. It could be the pressure plate is not properly set up or the step on the flywheel is not correct. Because there is no adjustment all of the parts must fit exactly right, there is no way to "fudge" (adjust) your way out of a problem. Maybe the pushrod is not positioned right in the slave cylinder. Don't force anything or you will bend the fork. Maybe the throwout bearing is not positioned right with the fork. Take it apart slowly, examining things as you go.

[Project Vixen]

And the answer is...

The clutch fork jumped the retaining ball and was too far down. From underneath, the issue was not apparent at first, except that the fork was completely bottomed out in the throwout bearing, which didn't register to me at first as a sign of the issue.. I could see that the fork was not centered on the shaft that goes into the slave cylinder. Rob Grady suggested we focus on that first, and when viewed from other angles the problem was quite apparent. We tried tapping the fork upwards to get it reseated, but it wouldn't budge until we loosened the bolts on the slave cylinder. Then it snapped into place with a satisfying 'ping'. Everything checked out after that, so we started up the car and all is good! It's still dripping a small amount of oil from the rear main seal area, which will require a little more exploration if it continues.

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[dmcman73]

And the answer is...

The clutch fork jumped the retaining ball and was too far down. From underneath, the issue was not apparent at first, except that the fork was completely bottomed out in the throwout bearing, which didn't register to me at first as a sign of the issue.. I could see that the fork was not centered on the shaft that goes into the slave cylinder. Rob Grady suggested we focus on that first, and when viewed from other angles the problem was quite apparent. We tried tapping the fork upwards to get it reseated, but it wouldn't budge until we loosened the bolts on the slave cylinder. Then it snapped into place with a satisfying 'ping'. Everything checked out after that, so we started up the car and all is good! It's still dripping a small amount of oil from the rear main seal area, which will require a little more exploration if it continues.

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If the rear seal is still leaking after replacing it, it might be due to either a constricted ventilation or a ridge was worn out on the crank where the original seal sat. If/When you do pull it again, look for a faint line around the main crank where the seal rides on. If you see one, that's a worn out groove and will cause the leak. You have a few options if this is the case:

1. First, make sure your crank case ventilation (black oil fill cap with the mesh jammed into it) is clean and is not clogged. If this is clogged, then all that pressure is forcing oil out the seal(s). You can pull the mesh out using care.

2. If the ventilation is clear, then make sure you install a double lip seal. This seal has a lip around the same area as the original single lip seal as well as another one more towards the front to act as a secondary seal. PJ Grady sells a beefy one that a lot of people like and seems to cure any leaks one.

3. Install a speedi sleave to repair the groove. It's just a thin stainless steel sleeve that is driven over the surface to create a permanent fix. You'll need to use Loctite 640 on the old surface of the crank prior to driving the speedi sleeve on, this ensures the sleeve is bonded.