4R70W 1st and 2nd Require Double Engine RPM
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4R70W 1st and 2nd Require Double Engine RPM
1997 F150 4wd 4R70W, Installed new engine at 160K, and had Ford Dealer put in new tranny a month later after blowing drive bands for 3rd gear. (Did not have time to install myself) The new tranny is under warranty but before I bring it in would like some comment. (Currently at 166K)
Problem: 1st and 2nd Gear, Engine is running double the RPM to get vehicle to accelerate, Kind of like when its -15F and you first start the truck, the engine will rev high when you first get going. I drove with this condition for 100 miles (to get home from the hills) and it did not worsen.Problem occurred after a 300 mile run at 70-80 mph, pulled off got gas, and kaboom..no pickup high RPM's as I pulled onto the highway, pulled off checked fluid, OK, no smell, and looked for leaks.
Background: transmission has only 4K, all while towing,4WD or Pop-Up bed camper. 80% is highway miles above 70 mph, the other 20% is offroad. Dealer installed Filter in cooler line, and I did verify that the new transmission came with a new torque converter and was considered "new" by the dealer (although they all are rebuilds).
My guess is accumulator spring broken, or bypass in shift valve, I did get an engine light the day before in the hills P1506 MFg specific drivetrain, but I saw this on the old tranny to.
Problem: 1st and 2nd Gear, Engine is running double the RPM to get vehicle to accelerate, Kind of like when its -15F and you first start the truck, the engine will rev high when you first get going. I drove with this condition for 100 miles (to get home from the hills) and it did not worsen.Problem occurred after a 300 mile run at 70-80 mph, pulled off got gas, and kaboom..no pickup high RPM's as I pulled onto the highway, pulled off checked fluid, OK, no smell, and looked for leaks.
Background: transmission has only 4K, all while towing,4WD or Pop-Up bed camper. 80% is highway miles above 70 mph, the other 20% is offroad. Dealer installed Filter in cooler line, and I did verify that the new transmission came with a new torque converter and was considered "new" by the dealer (although they all are rebuilds).
My guess is accumulator spring broken, or bypass in shift valve, I did get an engine light the day before in the hills P1506 MFg specific drivetrain, but I saw this on the old tranny to.