I just test drove what could be my next truck. The trany was just replaced with a Jasper unit and still has 65K of the 70K mile warrenty on it. The TC was replaced at the same time.

This being the first automatic diesel truck I've driven, I don't know if it's me or if there is a problem with the install. But: it seemed like the tc never locked. From a stop it the rpms would come up then it just stayed at ~2600-2800 rpm to 60. I could feel the 1-2 shift, but I couldn't say for sure where the 2-3 shift happened. The current owner said it was normal, but it seems like it would create a lot of heat and wear. Not to mention the fact that it seems like waisted performance.

So, is this normal or should I run?

 

Not normal. At 60 MPH it should have gone thru the gears and be in overdrive lockup, RPM about 1600 with 3.54 gears and normal tires.

 

here's how you test for TC lockup.

1. press overdrive button off
2. find a road you can maintain 45-50 mph safely
3. start from stop, accelerate through all the gears to aprox. 45-50 mph. then maintain speed. (if you let off throttle or brake, lockup is suppose to release) then while maintaining same foot throttle position, take your left foot and press on brakes. if you are in lockup, rpm will slightly raise.

normally from dead stop you should feel four shift (last shift is overdrive) then your rpm should drop when lockup occurs.

at least this is how my 97 operates...

 

ALright, thanks for the reply. I guess the search continues