Thanquol
Junior Member
2018 Tradesman 6.4 Hemi with the 66RTE(?) transmission:
A few months ago I had to hammer down on the accelerator while towing a small camper. Shortly thereafter the engine light came on and the trany was shifting gears in a crazy fashion.
Replaced the 2 filters, pulled the valvebody and replaced the modulator per the engine light code. Refilled with new Mopar 4 fluid. Works great and engine light is off.
HOWEVER, shifting is fine UNLESS I accelerate hard like on an on-ramp. Then the trany seems to stay “stuck” in the next lower gear and will not kick “up” to the correct gear. E.g. at 70 mph it normally runs at about 1800rpms in 6th gear. If I hammer it down, it stays “stuck” in 5th or 4th gear and runs at about 3,000rpms. And wont kick “up”. If I coast in neutral and shut the truck off a moment and then restart it- the problem goes away and it shifts normal again. Or if I stop and shut it off.
Is it a bad module again? The light isnt going on and it was a “Mopar” brand modulator. Fluid is topped off correctly.
Thanks!
A few months ago I had to hammer down on the accelerator while towing a small camper. Shortly thereafter the engine light came on and the trany was shifting gears in a crazy fashion.
Replaced the 2 filters, pulled the valvebody and replaced the modulator per the engine light code. Refilled with new Mopar 4 fluid. Works great and engine light is off.
HOWEVER, shifting is fine UNLESS I accelerate hard like on an on-ramp. Then the trany seems to stay “stuck” in the next lower gear and will not kick “up” to the correct gear. E.g. at 70 mph it normally runs at about 1800rpms in 6th gear. If I hammer it down, it stays “stuck” in 5th or 4th gear and runs at about 3,000rpms. And wont kick “up”. If I coast in neutral and shut the truck off a moment and then restart it- the problem goes away and it shifts normal again. Or if I stop and shut it off.
Is it a bad module again? The light isnt going on and it was a “Mopar” brand modulator. Fluid is topped off correctly.
Thanks!
