On my sisters 1992 Buick Regal Custom (has a Series 1 3800 but different tranny than my 94 though right?) she first noticed this like jerking and thought it was going to die or something but anyways i took it out to figure out what could be causing it...after a few drives i've found that when the car gets around 50-55mph and goes into overdrive it starts kinda jerking back, feels like a huge quick gust of wind hits the front, the jerking is really spontaneous...ive checked all the fluids and air filter those are all good...when it was doing that once i switched it to regular drive and it stopped. Also my dad talked to a mechanic about it and he said it might be the overdrive lock? (not sure what that is) and that you can cut a certain wire and it will stop. im not sure if that is the best solution so i thought id see what you guys think. i definitely know its something to do with the OverDrive just not sure what. the engine has 106k on it btw if that is any help. Thanks!

my dad called goodyear and he said its to do with the tranny but thats out of their area and that we should get in touch with a transmissions place.

i dont think that it has to do with the plugs because then it would be sputtering all the time this only does it at 50-55mph when it first shifts into OD. i've floored it at lower speeds with it has no problem whatsoever and it idles fine too

yea ive only noticed this occuring in overdrive and i have to be acclerating for it to occur...i think that the heat might make it worse too not too sure about that. i havent really taken notice about the uphill down hill situations :? yea it does have a tach but i dont recall the engine speed changing as it bucks.

http://www.bonnevilleclub.com/forum/...ic.php?t=16529

HI ...just my 2 cents....i was about to rebuild the tranny on my wifes 97 caravan...142,000 miles...it was bucking in overdirve...turned out to be a bad plug wire...lot cheaper than a tranny rebuild!....

This is sometimes refered to as "torque converter shudder" and it is the transmission that is shuddering, but the problem does not necessarily lie in the transmission. This problem was occurring on my car but went away after I replaced the spark plugs.

That is the exact same problem I had with my 96 Bonne.

Solution: Replace Plugs and Wires. Cyc#1 Wire was corroded all to hell, and it only showed up under heavy acceleration at about 60kph and higher.

Rather dangerous problem really, if you needed fast acceleration, you didn't have it!

You can confirm that it is the torque converter by doing this:

When it starts jerking, keep your foot on the gas. With your left foot, tap the brake once. If the jerking stops, it is indeed the torque converter. If the problem continues, it may be something else not the torque converter.

i agree with you...my wifes caravan was doing the same thing...i finally found out it was a bad wire by taking it on a long drive...and varying the throttle under load...ie with the convertor locked ....i found out that if you opened the throttle very slighlty...the van ran fine....a little more open throttle...and it started to buck...still more open throttle caused a backfire through the air cleaner....definatley an ignition problem....