727 problem

[Todd Wilson]

Ok got my truck back from the repair guy. 727 does an odd thing. He is gonna take it back in the shop to have a look but I wanted to see what the experts here think.........when the truck is cold.....it will  not downshift. You come to a stop at a light if you do not put it in N and back to drive or drop to low and back to drive as you sit waiting   it trys to start out in 3rd. Shifts up just fine if you do this. After say 10-15 minutes of driving the transmission is just fine. Stick ti to the floor and it hits passing gear. Stop at a light and take off and it works great 1,2,3......... 727 was rebuilt and new tork convt.


Any ideas?


Todd

[oldkimmer]

..........Seems the govenor is sticky...............kim............

[flyinlow]

I'm not a tranny guy, but check the throttle preasure linkage.  If it does not come back to the idle position at a traffic light it might make the trans stay in 3rd. When the car is cold the fast idle cam on the carb holds the throttle open a bit. When the choke comes off the idle position returns to normal. I'm assumming you have the choke hooked up.

[John_Kunkel]

The two most like causes are a stuck shift valve in the valve body or a faulty governor, the only way to know for sure is to hook a test gauge to the governor pressure test port. With the shifter in Drive and the rear wheels not turning the governor pressure should be no more than 2 psi.

If it's more than 2 psi the governor is the problem, if it's OK the valve body is the problem.