Hi. My names Jonathan, and myself and my family have been avid pontiac fans for years. My first car was a pontiac 6000, and then a sunbird and now two bonnevilles. The latest bonneville is giving me a pretty significant problem and I came here hoping someone has an idea as to what'* wrong.

2002 Bonneville SSEI, 3800 deluxe package(Heated seats, double electric seats, onstar, 2 person memory, hud, the works) with 118,000 miles. I purchased it used from a 2nd owner and while when I test drove it I noticed something a little wonky with the tranny, they said they had recently had the tranny rebuilt. Knowing that they generally go around 110k and 125k I figured I was in the clear and it just needed some minor tune ups. 3000 miles later and the tranny goes out completely. Took it to a local transmission guru who replaced everything(including the new hardened pieces) and he informed me that the previous "Rebuild" was just them slapping on the wrong size converter/flywheel or some such and machining it to fit.

Essentially when its shifting between 25mph and 45mph it slams into higher gear and then back down, i've counted as many as 7 slams. The car jerks enough for my head to come forward. The only way around it is to floor the gas or accelerate so slow as to not even press the gas. I've also noticed fluttering around 55 or so when it seems to drop in and out of Overdrive. I trust my tranny guy with my life and I know the work he did was good, so now I'm out of options. I know the catalytic converter is bad and I'm getting that replaced but that is the only code on the car.

Check the TCC swtich. https://www.gmforum.com/t284972/ Keep in mind this was on a 97 so your might be a bit different. Mention it to your trans guy and he may know what needs to be checked and adjusted.

Welcome to the forum.

Welcome to the forum!!! sorry to hear that your 02 isn't doing well we'll get ya fixed up

I think the TCC might be the issue. I tried the 50mph trick and it jumped up about 400 rpm and didn't come back down. Already liking the forum, ha. Thanks.

Hi Jonathan!

Welcome to the Bonneville Forum!

Please add your year and trim of your vehicle to your signature line. That way when you start asking questions in other areas of the forum, we all have a better idea on how to assist you. Click on "Quick Links" above, go down to "User Control Panel" and then click on "Edit your Signature" It'* pretty straight forward from there.

Then it'* our of adjustment. You will need to move it in about 1 tooth and drive it. Then adjust again if needed. You may need to do this a few times. But if you go to far with the TCC switch, the brake light will be on all the time and your cruise control will not turn on. So you need to get them balanced.

Welcome to the BonnevilleForum Jonathan. hope it all gets worked out for you. We certainly do our best to help out.