727 won't shift - help!

[WayneT]

I finally got my GTX on the road yesterday and found the tranny wouldn't shift out of first. I went back and adjusted the kickdown according to the factory service manual. It was adjusted a little too far back. Now it shifts into second but not third, even when I let off the throttle. I adjusted the kickdown to where it would barely push the linkage back and still no third gear. The trans was just rebuilt by a transmission shop and they put in a B&M shift improver kit. I'm thinking the problem is in the valve body? I plan to drop the valve body and check it to the service manual specs. Anyone have any ideas?

[MoparMarcIdaho]

the govener circuit plugged,easy to overlook sometimes,it spins on the tailshaft and tells the valve body how fast the car is traveling for shift points.

[WayneT]

How can I check the govener circuit? Can this be fixed on the car or would this be another trip to the shop?

[MoparMarcIdaho]

to whoever the rebuilder is and tell them what you suspect the problem is.If it was me,I would try just one thing.CAREFULLY,while the car is moving SLOWLY, forward in neutral,put it in reverse idling slowly.Less than 700 rpms.Somrtimes this will backflush govener circuit mabeye and save you and the rebuilder alot of hassles.Might kill the motor but shouldnt hurt anything if done properly.I have done it and fixed the problem once many years ago,use your own judgment OK?

[John Kunkel]

Before doing anything else, temporarily disconnect the throttle pressure linkage at the transmission lever and allow the lever to come full forward.
If the trans will shift to 3rd with the linkage disconnected, the problem is in the linkage; if not, the problem is internal.