I've got a 95 CTD that just started having the in and out of lock-up problem. Super annoying. I tried adjusting the old plus a new TPS with no change. I believe the cause is the transmission temp sensor. The connection between the wiring pigtail and the sensor itself is very loose. I can wiggle it around quite a bit. If I shove the pigtail all the way in the sensor, I can get the transmission to act normal for awhile. Is this connection supposed to be loose? If not, do I need to try to find the wiring harness & pigtail or will a new sensor tighten things up? Not sure if there is supposed to be, but there is no o-ring or any type of rubber on the pigtail that holds it tight in the sensor. Thanks!

 

Shouldn't be loose. If pressing it on better solves the issue for a while, replace the connector.

 

I've always hated how late the PCM commands lockup, especially in a diesel. The loose fluid coupling really kills the torque transfer to the wheels... You have a 47RH which is a pretty simple trans when looking at it electronics wise, as in there isn't any inside other than a pair of solenoids to shift lockup and OD. It has a simple three wire vertical plug for said solenoids, middle wire is keyed power, the outer wires are the grounds controlled by the PCM. Tap into the orange wire with black tracer and run it up to a grounded switch. Then when you're cruising you can flip the switch on and the oscillation in and out of lockup will stop. If you get a similar oscillation with OD you can do the same with the wire for OD and solve the problem for good.