I have a 200-4R tranny in a 1988 Olds and having problems with the lock-up converter. When cold for the first few miles with the selector in the D or D(O) position all is fine, but after that the converter will lock up every time it shifts into second, bogging the engine; no poop and terrible mileage. I recently performed an oil and filter change and with the pan off, removed the lock-up converter solenoid to make sure the orifice wasn't restricted-all was fine. After reassembly, I connected a 12v test light to the diagnostic port that feeds the signal to energize the solenoid so to monitor its operation. Took the vehicle for a road test and all works fine-signal comes on at 45 mph and drops out upon heavy acceleration and no throttle(high manifold vacuum). As a back-up test, I disconnected the harness at the tranny and went for another road test-same results lock- up with second gear upshift. The converter won't disengage till the vehicle is almost to a stop-comes close to stalling the engine. A review of the 200-4R hydraulic circuit shows two conditions must be present to have apply pressure to lock the converter-(1)hydraulic pressure to shift the converter clutch spool and (2)solenoid activation to block the bleed orifice so the converter signal hydraulic pressure can shift the lock-up spool. With the solenoid being removed and examined for blockage and finding nothing plus an electrical checkout, I'm puzzled. Could there be something temperature related, since lock-up works fine for the first few miles? A feel of the cooling line out of the tranny is moderately warm- nothing excessive. Could there be an internal leak or a weak/ broken converter clutch spool return spring? I need someone with expertise/experience with the 200-4R as I'm sure someone else has had this problem.
- posted
17 years ago