Another 126 Tranny Thread

[JerryBro]

My SD won't engage 4th gear when warm. I've done the due diligence thread searching and understand this is a sign of a big pressure drop during the 3rd to 4th transition. Fresh fluid and filter made no difference, so rigged a pressure gauge to the vacuum modulator port and found it at 62psi with the vacuum disconnected. With is adjusted down to 42psi the tranny will slip in all gears when warm. Even at 62psi, with the vacuum not connected to the modulator, shifts were not the hard bang I thought they would be.

Is it possible that someone set the modulator pressure high on purpose? I've had the car for about 75K miles and had to put a B2 piston in when I bought it, maybe someone did it then as a poor troubleshooting step?. I don't recall if it had the plastic or metal sleeve. Could this just be the result of pressure loss due to that sleeve being worn?

My Kompressor died over the weekend, and unlike it I am willing to spend the money to maske this one right again.