200R4 strange behavior

[SupremeClassic]

So I had my 200r4 in my '88 done by a shop that put a 2 year warranty on it. They installed a shift kit when I just asked for a rebuild (im gonna assume for pressure) and after driving it awhile it bangs pretty hard shifting down into first, and shakes.Then the lockup torque converter cuts on after shifting into 2nd and 3rd. I THINK( I'm not good with transmission stuff) it basically shifts and then the rpms go down a good bit. It only does it after the hard downshifts start (if I'm driving and I run her hard all these things happen faster). My dad said its the lockup torque converter, but he's not a rebuilder, but he has done several projects in his lifetime and was top 20 GM ASE in the country at one point. The shop is an AAMCO. And I did it because of the 2 year warranty. They say there's nothing wrong with it. So what is this behavior? I've been scraping the internet for info as much as possible. Apparently it's gonna behave strange and shift hard "Sometimes" with a shift kit?

 

[pontiacgp]

I would bring it to another shop that is reputable and knows the 200 r4 and get them to diagnose the transmission. Even if you have to pay for the second shop to look at it I'd do it. You need someone who is qualified with certificates to give an opinion on the transmission (no disrespect to your dad). If the transmission does have a problem and AAMCO does not want to fix try to get them to put their refual in writing. Then contact the head office with your assessment from the other shop and the refusal of the AAMCO shop

 

[Longroof79]

First of all, Aamco would not have been my first choice to have my 200-4R rebuilt. I would try consulting with one of the better trans builders who are proficient, and specialize in the 200-4R.
Where in the country are you located?

 

[pontiacgp]

and looking up the AAMCO warranties they don't offer 2 year according to their website

Depending on your needs, AAMCO offers a variety of Coverages:

• The AAMCO 90-Day Limited Warranty for Minor Services.
• The AAMCO 90-Day Limited Warranty for ElectronicComponents.
• The AAMCO 90-Day Limited Warranty for ManualTransmissions.
• The AAMCO 12-Month/12,000 Mile Limited Warranty for Automatic Transmissions.
• The AAMCO 36-Month/36,000 Mile Coverage for AutomaticTransmissions.
• The AAMCO Lifetime Coverage for Automatic Transmissions.