Tranny Help -Hard Shift Into OD Under Load
 

OK Gear Heads--My 4-speed auto shifts whiplash-hard into OD only under towing loads. Dealer didn't know what to do with it & told me it was better than shifting soft and mushy. Any fixes?

2006 Ram MegaCab 4X4
5.9 Cummins 4sp auto
bone stock
WW 5th wheel toyhauler

I've got 212,000 on mine and it to shifts pretty firm into OD when I'm loaded up and pulling the RV hard. However, I wouldn't call it violent or anything... More a function of the torque that's being put out and then a sudden shift.

I can somewhat control the firm shift if I back off the throttle and bring the boost down right before the shift. OD is by far the most firm out of all the shifts.

If you are in tow haul mode when that occurs it is because the torque converters locks during the 3-4 up shift. It does it at wot acceleration also. Mine shift very firm from 3-4 normally. In tow haul or at wot it shifts even firmer, enough to roll you head back.

the spacer for the overdrive clutch is to thin,. built wrong from factory.
mine was doing the same thing. if you dont fix it it will blow the piston right out of the overdrive clutch

Thanks for the quick replies. It does it worst under half or light throttle, and the same in either tow/haul or regular mode.