Hi,the test he did was called power braking, to see if the unit is slipping. It normally wouldn't shudder,but it hard to tell you what was going on without being there. The price is actulally reasonable, at least in my area. The price in NY for a rebuilt transmission, parts and labor is from 1800 to 2300. If you are unsure of the shop,I would get a second or third opinion,along with a scan for codes. These transmission had a problem with the pressure control soleniod,and also valve body issues. I will send you some info on service bulletins for this. The problem is that a shop may try the repair and sometimes it doesn't help and the unit needs an overhaul,they wind up not being able to charge for the lost time,so many would preffer to just go through the unit with it on the bench.
Hi, I have not heard of any problems with the replacement solenoids from GM. If you are unsure of the test tesults form AAMCO,you may want to have the problem checked at a dealer. They should be able to do the transmission pressure test as described in the TSB I sent, and recheck for any codes.The soft parts are the usual parts in a rebuild,gaskets,seals,clutch plates. Hard parts such as pumps,planetarty gears,are usually an extra charge needed.You can get a trans from a company called http://www.jasperengines.com/ for a little over 2K,between the shipping ang the installation it will be a little costly. You can ask the dealer abou the price of a SERTA trans,they are rebuilt for GM to their specs,and come with a good warranty. The problem with buying your own unit and having installed is, if there is a problem,the labor can become an issue.