Lockup not Actually Locking

blacksix

Member
Joined
May 15, 2002
Have a fairly fresh fairly stock 200-4r, works perfectly except lockup. D5 converter. Manually switched, new solenoid, tested in place with the pan off and blowing into it -- plunger moves. On the road -- no lockup.

Missing O-ring on input shaft? If this is the case, what happens to the fluid flow circuit when my switch is on? Do I still have the low cooling and lube flow in 4th?

What else might be the cause? Can the clutch itself actually quit working? Basically I want to know if it's safe to drive the car for the summer while building a serious trans, if I watch the fluid temps.

Thoughts?.
 
Do you have a scan tool that will tell you if your 3rd and 4th gear switch signals are getting to the ECM?


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Not electrical as all that is bypassed for now. Forget about all the switches etc. MECHANICALLY lockup is not working.
 
So when you put 12v to the solenoid you hear it click? Did you put the scanner on it as suggested above, does it show the computer is calling for lockup?
 
Did you follow the GM flow chart?


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OK so it's possible the O-ring and valve are missing from the end of the turbine shaft, will have to pull the trans to see I guess. In the meantime, if I keep an eye on the trans temps, is it safe to drive on the highway, or absolutely not? Or is there an issue other than heat from reduced cooler flow?
 
OK so it's possible the O-ring and valve are missing from the end of the turbine shaft, will have to pull the trans to see I guess. In the meantime, if I keep an eye on the trans temps, is it safe to drive on the highway, or absolutely not? Or is there an issue other than heat from reduced cooler flow?
With a D5 converter it shouldn't be a problem. Just watch your temps.
 
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