Lockup -vs- Non-Lockup

Dr. D

New Member
Jun 27, 2001
What changes to the valve body have to be done to change from non-lockup to lockup? I want to change out the 9" non-lockup converter to a lockup unit. Thanks.
The Art Carr valve required the pump to have an orficed cup plug drove out and the hole tapped for a 5/16-24 set screw to retain the valve and prevent rotation. I converted a pump back to a lock-up by removing the set screw and Art Carr valve from the front pump and installing a stock lock-up valve and spring in its place. Then I drilled a .093" diameter hole completely through the set screw leaving the hex intact. I then installed the set screw back in the tapped hole retaining with red Loctite (make sure you clean the threads with brake cleaner first). DO NOT tighten the set screw all the way down against the newly installed valve, just run it down just under flush and check to make sure the valve move freely with no binding. The set screw will now do the job of the stock orficed cup plug.
You also may need to install one check ball in the valve body side of the seperator plate.
You can leave the encapsulated check ball out of the end input shaft as Bruce (WE4) has told me it will just firm up the lock-up clutch apply.
My car still has a 9" non lock-up. I converted my Dad's car from the 9" non lock-up to one of Performance Transmissions' 9x11 and it works very well. His car was an 11.80 car on Nittos and 11.50s on slicks with the old convertor we have not got a time with the 9x11 installed yet. We have another car I'm working on with 9x11 that will be more serious when the engine is together and depending on how that car does I may switch mine back to a lock-up.