I am having some problems with a stock 2001 Allison. The truck it's also stock. It has ~250k+ miles.
Here are the symptoms:
ONLY when decelerating, towing a load with the truck in tow/haul, torque converter locked, speed approx 30-35mph the transmission will "shift" to a neutral state and try to "grind" back into gear. The condition feels similar to driving a manual transmission and pulling the truck out of gear then trying to "dry shift" back into gear. It is also intermittent. It happens sporadically. I haven't found anything that makes it happen or not happen other than the conditions mentioned above. The transmission operation can be remedied by shifting to neural then a forward gear or simply stopping and restarting.
The TCM indicates a P0846 & P0847.
I have checked fluid (bright red, clear, good), changed internal and external filters, dropped, opened, inspected transfer case (fine).
I have not check the harness for fluid (yet). I plan to try that this morning.
Any other ideas?
Here are the symptoms:
ONLY when decelerating, towing a load with the truck in tow/haul, torque converter locked, speed approx 30-35mph the transmission will "shift" to a neutral state and try to "grind" back into gear. The condition feels similar to driving a manual transmission and pulling the truck out of gear then trying to "dry shift" back into gear. It is also intermittent. It happens sporadically. I haven't found anything that makes it happen or not happen other than the conditions mentioned above. The transmission operation can be remedied by shifting to neural then a forward gear or simply stopping and restarting.
The TCM indicates a P0846 & P0847.
I have checked fluid (bright red, clear, good), changed internal and external filters, dropped, opened, inspected transfer case (fine).
I have not check the harness for fluid (yet). I plan to try that this morning.
Any other ideas?
