2 weeks ago, I had my trans rebuilt (original housing with all internals replaced). After the rebuild I did a test drive. Whenever I tried to give it full throttle, it would shift very rough, almost like it was slippng. It shifts great under normal driving, in fact it shifts MUCH better than it did when it was new. It is only when I give it full throttle that it shifts rough.

The mechanic said that it was caused by 2 things.

1. The car has to re-learn its automatic performance adjustment program. The rebuilt tranny is much tighter that the stock tranny and the car has to re-learn the new shift perfomance.

2. He said that my front engine mount was bad and allowed too much rocking, which magnified the tighter shifting feel of the rebuilt tranny.

These all made sense to me at the time, but here it is 2 weeks later and it is no better. I also took a closer look at the engine mount and it does not appear to be bad.

There is a 3 year nationwide warranty on the tranny, so there is no problem getting it fixed, but I don't have the time to get it into a shop right now.

Do either of those 2 explainations given by the mechanic sound valid ? Could this be caused by the computer or a bad mount ?

This is true, only if TAP values were reset. Do you know if the shop that rebuilt the transmission re-set the Transmission Adaptive Pressures (TAP) using a scan tool after the rebuild? If not, this needs to be done. The PCM will then re-learn TAP values.

Yes. They did reset the TAP.

My nightmare continues . . . . . . .

Today, I was backing out of my driveway, which is inclined, and I had to floor it to get backed out. Now, every shift is VERY hard. It feels like the trans/engine is going to jump out of the car.

I called the shop this morning and they said it could be a computer problem.

I am taking it to Cottman this afternoon.

My initial thought is a 730 code (incorrect gear ratio) or some other code that is commanding max line pressure in the trans. These do not set the SES light so without a real scanner you may not be able to see if the codes are stored or not.

@jastek1 - How much was it to have the transmission rebuilt? I was just quoted $1800-$2500 for mine (2000 ssei) and it seems high to me, but I don't know...

At the WalMart parking lot the other day a newerGrandAm drove by with the same sounding transmission noise and I got a little angry that they put the same faulty transmission in a car as expensive as the Bonneville.

Bumping this topic. I was told I need to rebuild my transmission in a 2000 SSei with 88K miles, for about $1800 to $2500. Is that a fair price? I don't know....

Bonnie, where did you get that estimate - at the dealer? For an independant shop, around here, that is high. The high end of an estimate would be about what your starting point ($1800) is. If you're going to have it rebuilt, I'd suggest a good local tranny shop over the dealer, or a chain.

We charge 1200 to remove rebuild and reinstall the trans. Parts that need changing/replaced/upgrdaded etc.. are extra and can cost any where from a couple hunderd for a stock rebuild to a few thousand for a complete race trans.

$1200 sounds a bit better than $2500. I'll try another shop, or more, to see if I can get a better price.

Thanks for the input

My rebuild was $2,800 (using my old case). I know the cost was high, but I was on vacation in the Smokies when it died, so I was at the mercy of the local shop. I called a shop near my house (Cincinnati, Ohio) and they told me their cost would probably be in the $2300 - $2,400 range.

Since I first posted this, my rebuilt tranny completely died. I completely lost reverse and every gear change felt like the engine was going to jump out of the car.

The shop decided to flat bed my car back down to their shop and fix it. They tell me that there was a warped plate that allowed a gasket to blow. I am no mechanic, but I think there was more to the problem that he has not told me. But, I have it back now and it runs fine (for now. . . . .).