Join Date: Dec 2008
Location: Tyler, TX
Thanked 407 Times in 347 Posts
Don't buy-into the idea the Kevlar or other aftermarket clutch material is better, you NEED more discs.
Why do I say that? A lock-up TC is really no different (in lock-up) than a standard clutch, grip is a function of the coefficient of friction, force and area.
You can't increase area w/o more discs (double disc for example).
You can't increase TC pressure (lock up) because after a point (not far from factory) and generatae excessive heat and stress on the piston seals and they fail.
You can't really change coefficient of friction, except to keeep the ATF clean. Different clutch materials may have more friction, but that means they will wear out other components instead.
From what I have seen, the single biggest player in TC problems with regard to slipping is leaving the ATF in too long then changing it. As ATF ages (heat and time) the coefficient of friction changes to the positive, that is to say it has more grip with age and heat cycles. Now you change that out and put in new ATF with a lower fricition coefficient and the trans is shifting at the adaptive it had for the old "grippy" ATF so you get slip. Not enough to notice or set a DTC, but some. This slip in higher power vehicles can rapidly degrade the clutch packs, including the TCC.
The best thing to do is keep the ATF clean and reset the PCM/TCM every transmisison service by pulling the KAM fuse for 5 minutes.
'93 F-250 HD, 7.3L IDI, 5spd - FARM TRUCK
I Support: Trailer brakes an every axle over the towing vehicle's GVW; CDLs for RVers; Safety inspections for ALL vehicles and 6 axle trucks (97K GVW proposal).
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote - Benjamin Franklin
I vote for LIBERTY!