1992 V6sei auto gearbox repair

[Dean]

The clutches will only suffer if you drive it with the fault, i wouldn't think it is the torque converter at this stage.
Does drive return once the oil temperature drops back to ambient? and how was forward drive lost, was it fine until you stopped and then it wouldn't move forward again? or did gear selection become increasingly restricted until it would no longer drive?
oil colour?

D

[MTXM]

I hope the t/c should be good if there is still strong reverse and I thinking more likely the valve chest, which would certainly be preferable to another engine/box removal! Is it really possible that the clutches could burn out after such a short time with the earlier governor issue? The first task will be to drop out and check the oil, although I will speak to the mechanic before removing the v/b. I also have a spare v/b that could try. Regards, Matthew T.

[Dean]

If the clutches are allowed to slip they can overheat very quickly, they are man enough to handle a good few hundred thousand miles of use and are much more resistant to overheating than a dry clutch but the concern is if they start to shed material in the box it can get into everything else.

If the new governor is fitted ok and working correctly, given the symptoms then i would guess it has to be the valve block, do you know what valve stuck last time?

D

[MTXM]

Thanks Dean and on the previous occasion the car still had some drive while clutches were slipping and I had also covered a few more miles. This time after refitting the governor the drive went suddenly and completely and I had only covered about 1/2 mile. Unfortunately I do not know which valve was effected last, although the characteristics now are quite different with no forward gears at all! I am fairly confident the governor went in correctly without damaging any seals and previous governor seal issues have affected changes and removed reverse, which I still have this time. With regards, Matthew T.

[Dean]

Yes the governor is part of the reverse inhibitor circuit, the main signal for inhibiting reverse actually.
Sounds like a valve block issue, very much like a stuck valve if drive just suddenly vanished.
i think first uses the low clutch the same as reverse but also uses the forward drive clutch as do 2nd 3rd and maybe, i think.... 4th, so if you had no forward drive clutch, surprisingly, given the name, you would lose all forward drive, off the top of y head this could be the valve block but equally it could have blown the seal out of the forward drive clutch slave cylinder or cracked the forward drive clutch drum and the retainer ring for the clutch pack has dropped out, lets hope not though as that is a box out job.

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[Dean]

explained here by the guy with the LOUD intro


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[MTXM]

Thanks again Dean and I am more inclined to think (and hope) it is a valve block issue rather than some other failure, after such a short run and the box having just been rebuilt. The v/b has also been rebuilt of course, but by another specialist and there seemed to have been an problem with their work before. I think I lost the drive when testing kickdown in third gear around 30mph if that is at all significant. I shall let you know what the mechanic has to suggest. With regards, Matthew T.

[Dean]

An oil drain would be the acid test as you would have a section of the outer lip of the clutch drum rattling around in the bottom of the casing.
I do have in my possession a box that has done this but not something i have first-hand experience of so couldn't say but i will keep my fingers crossed for valve block, it wont be the governor as of all the ways it can fail i can't see how it could prevent 1st gear selection.

Good luck
D

[MTXM]

My apologies Dean and I just realised I missed one of your posts! The drive has not returned after cooling and was lost suddenly while in motion and I think I was testing kickdown around 30 as mentioned above. I will certainly take a look at the oil pronto. That was reassuring about the t/c and clutches, which did not appear to be slipping as before. With regards, Matthew T.

[xantia_v6]

Clutches don't burn out quickly, and would always be accompanied by burnt fluid, which you would have noticed. The torque converter also operates for reverse gear, so I think that your fears of major mechanical issues are probably pessimistic.

It would seem to be pointing back to the governor or valve block. What are the chances that a fragment of rubber seal has migrated to somewhere else it shouldn't be?

If it worked well initially, then I think that you are probably diagnosing a completely new fault, transmissions don't often have intermittent faults.