RE48 Shifting and slipping problem

[Revery Hi Yo]

I have a 2007 2500 with 5.9. Recent trip after dropping a 9K trailer with-in a few miles all of a sudden it started slipping in 2nd gear. It always pulled great before with no indication of slipping. Might mention towing has been about 20% of last 100K miles. It will not shift out of 1st, but let off gas and it slips into 2nd accelerate easy it's ok but a little harder on accelerator and it starts to slip. Won't shift up to 3rd with out letting up but once in gear doesn't seem to slip, same procedure to 4th and then it's locked and no problem. Scan does not display any codes. At 47K prior owner installed ATS 5 Star Converter and ATS tow valve body for better towing performance. Now has 168K but trans has had regular and routine service. Anybody have thoughts about problem. I thought maybe only valve body issue, but tranny shop guy says anytime it slips if worn out. Been ripped off before so trying to gain some knowledge. Thanks to all.

 

[BenchTest]

I'm not a trans expert, first and foremost. Any discoloration of fluid or burned smell? 168K seems like a good mileage to have a failed trans. The slipping could be caused by a lot of things, but worn/smoked clutches would show up in fluid color/smell (normally).

 

[Revery Hi Yo]

Fluid looks good, no smell, no debris of any sort. Level is good and the fluid shows no sign of problem and never has as I check it often. Text chat with ATS and they thought valve body issue. They supplied HD torque converter and valve body for towing which was installed by prior owner at 48K miles. I thought it odd that the slippage occurred "all of a sudden" with no prior notice of forthcoming problem. I had just dropped off the trailer after a 130 mile trip. Thanks for your input and anu additional thoughts.

 

[Ian1111]

Your intermediate band could have the link broke and bent or the band is worn out. If you get it, rebuilt put a super servo in it and the green lining band. You won’t have any more problems after that.

 

[Revery Hi Yo]

The servo actuator lever was broken at the joint, I'm replacing it with a billet one. Everything else seems to be fine. Thanks for the reply to mt dilemma. It will be back together next week, I'll post how it turned out.