Hey guys, read a lot of other threads but none seem to have the same symptoms. Ok I've had my coupe on the road for about 5 short trips, seems to do this only after its warmed up, but sometimes doesn't either. Ok so reverse is always fine, shift into drive and it doesn't really want to go, like slipping, shift down 2, to 1 and all the same but seem alittle better the lower the gear. Fluid is correct, modulator is hooked up correct. Tranny has been sitting for about 6 years and never gave me a lick of trouble before. Seems to be something sticky as it only happens sometimes, any good cleaners or ideas of what it might be just thought I'd ask before I dig in. Thanks much!
My father inlaw bought a 49 Lincoln, has a 400 in it and had been sitting a few years. It was fine the 50 or so miles home, it sat for a week and he got in it to bring it to my house to work on. He called me about halfway here and said it was shuttering really bad and slipping. I made a few calls and the way I understood it, on the 400s if they sit for a few years the clutch material starts to flake off. Hince the shuttering. We had to have it rebuilt. When we pulled it it looked new( no road grim on it) and still had the sticker from when it was built before.
Yikes, well everything else in this thing is new so if I have to go threw it I guess everything would be new and I wouldn't have to worry about it lol. Kinda just wanted to run it before it snows and rebuild it over the winter.
I don't think 400 TH clutch material goes away any more than any other, but I do know a stock style 400 filter will plug with debris and cause the problems you describe, worth a look see . Also check to see if the electric "dump" solenoid is tight ,couple of screws . Vaccuum is very important to operation of the modulator so that's another couple things to check . Good luck .
Sounds like the seals are old and hard which causes the fluid to bypass the piston which pushes on the clutches. And this is what causes your slipping. Only on O/H will fix it. A can of xmission conditioner will make the seals swell and might make the slipping go a way. But the slipping WILL come back.
Forward clutch sounds like seals have hardened up. You can try some of that trans conditioner stuff and see if it gets better. That will tell you if the seals are going. Reverse demands more pressure via valve body and pressure regulator, so it usually works, and it uses a different clutch. First, drop the pan, and if reasonably clean (no chunks or sludge from clutches), then seals look to be bad. Usually seals get better when warmed up, so that seems to be opposite to what you are saying, but try the pan drop and inspect, then go from there.
Sounds like forward clutch seal, change filter and add new fluid. See if it gets better, especially when warmed up. If so you can try the additives, but that is only a temporary fix and will fail more and more.
Thanks for the help, I agree just a temporary fix, think I'm just going to pull it out and go through i, then I won't have to wonder if I'm going to make it home from a show some night.
It sounds to me like it's just low on fluid. Some fluid may have leaked out while sitting around. If it sucks a little air in it would be slow to ingage in forward. Reverse uses a boost valve to increase preasure and would likely feel firmer even with air in the fluid. Good luck.
Yeah I've been messing with the fluid level too. Started off that was what it was but now it keeps doing it and is definately full. Hey nice T coupe by the way!!
The filter material in the original filter is a Dacron material that plugs pretty easily; when doing high performance transmissions I always replaced the filter with a screen type, the same filter as used in the Allison 540. Where the pickup tube enters the case (pump) I always installed two O-rings which would give you a more positive seal. It could also be a forward clutch seal, checking line pressure would narrow down your problem about 60 -65 psi at idle in drive and 115 -125 in reverse at idle
If it sat six years, I'd change the seals, to check, drain all the old oil, install new oil, it has a seal conditioner in it, seals will soften, but the tranny will go south soon after.
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