4T60E had TCC clutch failure issues but suddenly drives fine
Hi guys, I posted a while ago about my 1997 LeSabre, 3800 Series II, 2.84 ratio 4T60E. Car has 70K miles on it. About 1500 miles ago, the car developed a problem where the TCC clutch would start unlocking (banging hard) and locking back up, repeatedly, once the car was very warmed up. This problem only occurred in o/d and lockup, over 50 mph, under load going up a significant hill (if you really tried to get it in lockup and bog the motor down you'd really get some repeated, hard banging from the TCC). The transmission fluid smells very, very burned. The rack failed on this car, and I had to take my mother'* car back to college, so she ended up driving the LeSabre for a few weeks. When I just got the car back, I can not get the TCC to act up -- I drove the car for a 2 hour trip. When I'd find a good long hill on the highway or main roads, I'd get the car in the 50-60 mph range, let the car get into o/d and TCC locked, and then progressively increase throttle, trying to replicate the TCC banging/shudder. The transmission seems to be completely fine. The TCC is locking properly (at first I figured the clutch had failed entirely, so it couldn't start failing under load, but it is definitely working as it should). Fluid still is burned. Is it possible that a freak problem, like an intermittent engine miss under load, had caused the TCC to disengage harshly under load, burning the fluid and leading me to believe the trans was the cause of the problem? I had the dealer scan for codes, and there were none. (obviously the TCC mechanically failing will not trigger a code, but an ignition wire/bad spark plug will cause an SES light) I'm tempted to change the fluid and filter and see if the car still continues to drive fine. My thinking is that if the fluid burned as noticeably as it did, the trans is or is soon to be needing replacement. I am getting an Intense PCM this week, so I need to make sure the transmission is ready to handle a significant power increase (exhaust was also changed to a full mandrel bent 2.5") I already bought a 30k mile used trans and an engine hoist, anticipating the trans needing replacement, and now it seems to be fine. My mother drives a lot easier than I do, so I'm worried that the problem is going to come back with me driving. However, my bat out of hell wost-case driving on the 2 hour test trip could not replicate the TCC problem even once. These transmissions are such a pain!