I own an 84 Eldo 4100 with 80,000 miles. Trans works perfectly around town at speeds below 50 MPH. Every time I drive more than 50 miles on the freeway and come to an off ramp stop, the trans shudders and affects the idle just prior to a complete stop. Never stalls, but almost does. Then leaving the stop, the trans will upshift early and harshly and have less power. I'm aware of the issue with TH125 transmissions where the lock up soleniod or brake switch fails causing the same issue but my experience was the car did stall and not affect upshifts.My question is, do I replace the TCC solenoid.

 

Trans is 325-4l, tcc sol could be sticking. If it acts like a manual trans and you did not press the clutch coming to a stop.

 

I have exact problem,manual trans W/O pushing clutch at stop is great way to put it. So how do you fix it? I think you can test it by unpluging wires that go into trans, but is it easly to replace?

 

You could unplug trans to see if condition goes away. If it does, check brake switch adjustment - both. If you have no trans experience it would better to find some who does to do repair. It is not recommended to drive indefinately with trans unplugged.

 

The replacement of the TCC solenoid fixed my car yesterday. You ask if its difficult to do. Not at all if you can remove a trans oil pan, have a torque wrench to reinstall the bolts you remove to get the solenoid harness out and the new one in. The solenoid has approx 8 inches of harness (2 wires) attached to it so it must be threaded thru all the pipes within the valve body. The new solenoid rattles when shaken in your hand, the old one made no noise at all because, I believe it was stuck.