My 2011 3500 Dually 6.7 automatic totally stock with 40k miles. as i was pulling my 38' 5th wheel (bout 13k pounds) for the first time when i noticed 1st to second gear shifted good, then the next shift when the truck reached 2600rpm the rpm increased 200 rpm quickly as like it was slipping to 2800 then shifted good, and also did the same thing on the next shift, 2600rpm increase 200 quickly and shift good at 2800rpm. i did have it in tow/haul also, trans temp was 170, did not see an increase in temp the whole trip. Anybody experience this? is it normal? what to do? Thanks for any help.

Donnie

 

I assumed the roads were dry, your tires are in good shape and your ATF level is in the proper range (must be checked level, hot and idling in neutral) and the right color (red, not brown). I would keep an eye on it and if it does it again take to the dealer and get it fixed before your powertrain warranty expires. There really haven't been any reports of tranny trouble to speak of on here on stock 4th gen autos. The 68RFE appears to be holding its own. That said, apparently the 2011 HOs had a better torque converter. Also wonder if you have the latest flash from the dealer. Under a previous flash my trans stuttered a couple of times between 5th and 6th when climbing a steep mt. passes mostly empty. Hasn't done it since I got a newer flash. Oh! And welcome!

 

Thank you!!! Yes ATF looks good, level and color. Brand new tires, dry road, perfect 75 degree day. Love everything about the truck, MUCHO MUCHO STRONG!! just noticed this and it bothered me a little curious if it was normal. i think i will drop by the dealer and ask them at least. Thanks for the reply