Sun. I was taking my 10k 5er to the campground & merging onto eway the 2-3 or 3-4 (not sure which) was extrmely harsh then again an hour later in town. That was with the attitude set @3/3 with T/H on. Lowered attitude to 1/3 & it did not do it anymore. Any ideas ? I don`t rod the truck hardly ever due to stock tranny & fuel prices. Normally drive it 0n 3/1 or 4/1 on hiway, 99,000 on truck. Been using AMSOIL syn. torque drive since 20,000. hopefuly trans is not going, no extra $$ right now.:(

Did you let the tranny learn with the extra power? Also I wouldn't tow with the juice set to anything over level 2 with a stock tranny.

I have been towing that trailer fairly regular for about 2 years, 1st time it has happened, But haven`t towed it in 2 months though.

I just got back from Disney pulling a 8000 5er, and on the way there after a couple of rest area stops the tranny shifted real hard getting back on the interstate. The outside temp was around 90 and tranny temp was around 160. My truck is stock.