Any bonnie owners experiencing harsh shifts from 3rd to 4th? 97 bonnie....111,000 miles. Its seems that if u "baby" it up to 46 mph....the shift is rough.but if u get on it...the shift is smooth. A pcm update maybe?

I had that after I got my tranny rebuilt but its not really in those gears its at a certain RPM I think like 1500 - 3000 RPM like at highway speeds or if Im going a certain speed that keeps teh rpms in taht range.

my 97 Riviera goes the same thing. I get a really bad surging as it'* shifting into OD. if I'm accelerating fast it'* fine just like yours. The surging on mine can be really bad at times though if I"m in OD and trying to accelerate without downshifting.

http://calid.gm.com/

use your VIN to see if its possible to update your PCM.

there is a TSB that addresses that problem, It is described as a 'Chuckle" by GM The correction is a chip called a MEM-CAL that changes the shift points

"Chuggle"

And it MAY be that, or any number of other similar issues. Symptoms with trannies are hard to describe.

My VIN is "invalid". Sometimes I really hate computers.

chuggle is a funny word. Pretty sure nobody has ever come to the dealer describing a trans liek that.