Originally Posted by ToledoRob

so a while back I discovered the problem and posted on here in a separate thread. Anyway before you pay for a new transmission or torque converter try this and it will cost you like under $25. I assume your cars are also AWD. And on the passenger side there is a small transfer case only holds like 1 quart of gear oil. The drain is easy and uses a 3/8 square drive plug. It’s a bitch to get to the full plug out it’s the same type but I needed to buy a belt tensioner to get it out. Not much room. Drain the old oil as the GM approved fluid I also added a Amsoil friction additive and it fixed the problem completely. I couldn’t believe the difference. Good luck and do this before paying anyone to do anything. It’s worth the effort and cheap just to make sure it’s not the same problem.