OK. my car has had this problem ever since i got it a year and a half ago.

whenever you're driving and the car has warmed up a bit, and driving around 60-70 km/h, enough for the TCC to engage in 3rd gear...the TCC will engage alright, and then if you jerk the gas the whole car will sharply shudder for a second and unless you give it gas AGAIN, the TCC will remain locked up. like it will shudder (the RPM'* will go up 200 or so, fall back down, then climb up about 500-600 as it disengages)... that only happens sometimes. other times you won't get the shudder and it will just be smooth. is this normal.

other times when the transmission gets very warm, the TCC will almost not apply at all. when it goes to do it, you'll get this gRrrRRRR noise as the RPM'* slowly drop down but suddenly it will start rhythmically jerking with the RPM'* jumping up and down a few hundred...like it'* slipping and catching badly ... you can tell the TCC is still engaged at this point until you floor it and get out of that mess.

the fluid and filter were changed last year and they said they didn't notice anything special about the transmission that would be causing this behaviour.

the vacuum modulator was replaced a month ago, to no avail.

the TPS was checked today and it gives 1V at idle and 4V at WOT. it seems to be smooth in between.

there are no codes stored in the computer.

whenever it locks up, there is a noise...i want to say grinding but that'* a bit harsh...it sounds like a solenoid applying.

i took it to like 3 transmission places who either say it'* normal and that it'* an engine problem. they probably just say it'* an engine problem because it takes about 30 minutes of driving to realize what'* going on. i've changed the air filter, fuel filter, o2 sensor, pcv valve, spark plugs/wires, battery, alternator and oil all within the past year and nothing fixed it.

IF it is the solenoids, how easy are they to replace? do you take off the side or bottom pan and are they easy to access?

Edit: Also, when driving around 40-60 km (usually) there is sometimes an audible huMMMMmmmmmmm that doesn't last longer than 5-6 seconds and doesn't seem to be affected by engine speed... i don't know, maybe low tranny fluid pressure is causing this whole thing? Sometimes there is a rattle when you start up the engine after it'* been sitting and a website (consumerguide.com) says that in 92-95 bonnevilles this condition can be caused by a starved transmission pump...

also the haynes manual states about the TCC: "If you detect a "chuggle" or "surge" condition, perform the following check..." and the check is the brake switch check, and it says if that passes then....yes you guessed it, take it to a shop. what are these chuggle and surge conditions indicators of?
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1992 Bonneville SE
~245,000 km




<font size=-1>[ This Message was edited by: Greg on 2002-05-06 21:02 ]</font>

My car does the same thing.

My dad works for a company (Torrington) that manufactures parts (bearings mostly) for our transmissions, he'* talked to the engineers who designed the 4T60E and he tells me that it is a design flaw, the TC is too eager to lock up and stay locked under light throttle. It is annoying as hell when it does it in my car, when I am trying to be gentle and save my gas. So I just get on it harder and it goes away. BTW the problem seems aggravated by bad gas (from el cheapo stations), when I put good gas in (Mobil usually) its not as bad.

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Cameron
1992 Pontiac Bonneville SE, K&N cone, stereo
145,000 miles and triple digit speeds no problem!

<font size=-1>[ This Message was edited by: csprague on 2002-05-06 21:26 ]</font>

hmm, interesting.

http://www.bonnevilleclub.com/forum/...106&forum=6&14

now i'm starting to get the 'classic' GM tcc solenoid sticking failure...it wanted to die on me at a stoplight today.

funny thing is that it wouldn't actually die because it'* probably so weak it can't keep the fluid inside the torque converter clutch enough to actually stall it. guess i found why the shuddering/slipping was occuring. :P

finally an excuse to get them to replace the solenoid.

Here check out this site:
http://www.transtec.com/specific_trans/4t60e.htm
It has all the trouble shooting specs.