tranny slippage

[necromancer_tat]

I have a 1995 trans am automatic that i bought recently, it runs and drives awesome as long as i don't pin the gas to the floor. If i stomp the gas pedal the car runs great all the way up till about 80-90mph then when it goes to upshift the car acts like it's upshifting and then downshifting a whole bunch of times really fast. if i let off the gas the car upshifts fine and then it'll keep accelerating.

what can cause this? the trans was rebuilt 20k miles ago according to the previous owner, he said he never had the problem but he never really pushed the car above 70mph.

what should i check? is it an elctronic problem or a mechanical problem?

 

[melsg5]

I would check with a shop that specializes in transmission repair

 

[necromancer_tat]

I would check with a shop that specializes in transmission repair

thanks, I was kinda hoping that someone on here had had the problem before and could steer me towards the right direction without involving a tranny shop. most repair shops i've ever dealt with will usually try to steer you to a full rebuild and new tourque converter... the tranny was just rebuilt 20k miles ago.

 

[GatorIsaac]

Sounds like the downshift linkage needs adjustment. First my disclaimer : I have never been under the hood of a 1995.
The models I have worked on have a downshift cable on the throttle. It usually attaches on the same side as the throttle cable. The cable will pass through a hard mount within a few inches of the throttle. The adjustment is here. On older models the proper adjustment procedure is:
WITH ENGINE OFF
Pinch the release tabs on the adjuster and allow it to withdraw as much cable as it wants.
Keep the tabs pinched and have a partner hold the gas pedal to the floor.
Release the tabs.
Done.
fine adjustments can be done from this reference point to make the downshift more or less sensitive. Yours is now too sensitive.