When I have the cruise control on my car, 1992 L98 TPI, and am running at about 75mph, everything is ok until i come to a small hill.
When the car accelerates itself the car shakes somewhat violently until the gas goes back to where it was at cruise.

It will do this w/o cruise on but not as bad.
Any suggestions?
Thanks

^
pleae help me with this

Have you tried this without the cruise? It's possible that your transmission isn't downshifting and the increased load is causing a vibration - possibly a bad rear transmission mount.

It will do it without the cruise but when I press the gas a little more it stops it
Could it be the timing causing this or a lack of fluid pressure in the tranny causing it not to downshift?
I have a 92 B4C, I noticed that it will shift into OD @ WOT. Could this have naything to do with it?
Trying to help you guys help me

Could be a driveshaft problem or a weak Yoke.

Hey Jason, My car does the same thing, and so does my friends truck(92Chevy). I have not figured out what it is. Mine does it worse when the AC is on. It is almost like the torque converter can't unlock itself and is causeing the shaking. If you find out what it is let me know.

That is exactly what it feels like!
Hey great answer bro,
reckon I could rig up a switch to control the lock and unlock?

Let me start by saying it may be the torque converter. My 82 K5 Blazer is starting to do something similar when coming to its first full stop after sitting a week in between runs to the dump. But,,,,what's all this talk about downshifting, converter unlocking, etc. on small hills? My 86 IROC will climb everyone of those monster hills on I-64 between Richmond, VA and Sam Black Church, WV (with two passengers, suitcases, guns, ammo, etc.) without ever coming out of overdrive. If you've got any power at all why would it be trying to downshift? Just curious. Just though of something else....My 81Z used to do something similar (350 with an electronic Q-jet) till I got the throttle position sensor set correctly after installing a new carb.

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Z's r Best

[This message has been edited by Z's r Best (edited October 04, 2001).]

Not downshift but unlocking the torque convertor.
I dunno, it aggrivates me bad.
SO you think it is the torque converotor?
Would changing the tranny fluid help this at all?

85,

Changing the trans oil couldn't hurt, unless the oil has never been changed and you have eleventy-jillion miles on it.

My guess is a sticky TCC or possibly maladjusted TPS or TV cable. It could also be a OD sprag that is slipping a little, but I would suspect that you would feel that worse unnder heavier acceleration on those hills. Since inspecting the sprag clutch for the OD shell would require removal of the transmission, I would check the easier things first and change the oil and filter in the trans.

Anyone know where to contact GM Tech? He could probably shed some real light on the situation. I'm just a hack at transmission problems.

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Later,
Vader
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Thanks for your help everyone
I guess I will keep driving it until it doesn't go anymore
GMTech won't help me, but that is another unrelated story!

you probably have a broken or warped flex plate

You might wanna make sure your plug wires and especially your coil are good. I had an Olds that would get a violent shudder under light acceleration while cruising at highway speeds. It did this only at high cruise speeds. I replaced the coils and it went away for about 8 months, and then came back, I replaced wires and it went away for good. When you get a high load (accelerating while in OD)miss your engine of course loses power and then your TC unlocks creating the shudder. Just a thought.

Bob

i had the same problem a while back.tried the driveshaft that didn't work looked in the rearend no problems either.turns out it was a cracked flexplate even a little crack around one of the bolt holes will cause this.check both the tq. converter flange and the crank flange

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