changed left front transmission mount and left rear trans mount and passenger belt motor mount and put four tires on car and now i have a shimmy or vibration that happens only when i have pressure on accelrater. if i am crusing down the street with foot off throttle no shimmy but as soon as i touch gas pedal i get bad shimmy rechecked all sub frame bolts and motor mount bolts any help would be appericated my wife is dying to get her car back

how is all of your suspension parts?,tires balanced? Lugnuts are tight? Recheck your torque on all the cradle bolts and everything you had taken a part?

when you're putting gas on the throttle on the street (when you're getting the shimmies), put the car in neutral, and then put gas on it again - you'll find out pretty quick if it'* tranny or otherwise... then you can work from there.

just my .02...

matt

It may be that the drive axles are out of alignment because the engine moved while jacking it around while changing mounts and/or if the engine was raised while the car was not on a level surface.Don't ask me how I know this can happen.Something related to a "dumbsh*t award".Check to see if the engine moves alot when in gear and given some throttle and causes the engine to drive axle alignment to change.Missing,broken or loose mounts can do this.Butt the car up against a concrete parking abutment,apply emergency brake and look for engine movement while somebody slowly applies throttle.

talked to some trans specialist and they recommended replacing axles and loosen subframe and reattach it evenly and it should fix it say r/* axle is misaligned
man i sure hope so another question on same car popcorn noise while accelerating exhaust doughnut moving?? sound right

There is a TSB on a shimmy at about 37 mph and above. Origionally, GM said to replace the back transmission mount but as time went on, technicians were finding that this dosent cure the problem...thus GM came to realize that is a torque converter issue.. which you seem to have narrowed it down to.. You can go to your dealer and inquire about this but most dealers are lazy and play games..I work at one and see first hand. According to the TSB, you need to replace your eprom (95 and below) with an "updated" one. However if you have an upgraded performance chip, there is a plug in trans tuner that will take care of the problem.. I had the same bull to deal with. Hope this helps.

update transmission will be going in next weekend because it is shot
metal and clutch parts in trans pan but still thanks for the help

another update changed all four motor mounts/ transmission mounts bought and installed 4 new tires replaced transmission and still have the shimmy while accelerating could use some more insight from anybody that has seen this. and no codes either in trans or abs or engine :? so what also has been replaced is both axles.

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Thanks

I don't think it has anything to do with the trans or mounts (or axles). Check to be sure you don't have an ignition problem first. Sounds very much like you do.