904 transmission puzzler

[65moneypit440]

Having never torn into a transmission before, I probably won't be attempting to fix it myself, regardless of what the problem is thought to be. Thanks in advance for reading and for any education/advice that you care to give.

The trans (904) and engine (318) both came out of a 1987 Ram 1/2 ton pickup, no idea how many miles, now in a 1965 Coronet 440 hardtop which just completed a 1700 mile trip. Trans was professionally serviced (fluid and filter) before being run, but had set for a few years. The issue: up shift to 2nd doesn't happen until 1-2 miles (3-4 minutes) after cold start-up, running about 3k RPM. Up shift to 3rd usually happens a minute or so later. This happens regardless of whether I manually up shift or start out in drive.

Downshift at a stop doesn't happen for another few minutes; it wants to start out in 3rd. Once everything seems to be warmed up, it up- and downshifts fine. Fluid is normal, measured hot in neutral, and runs through a cooler in a new aluminum radiator. Trans pulls fine otherwise, and passing gear rod seems to be adjusted right. These conditions existed before the trip, and haven't changed.

What other info is needed? Thanks again for honest input....yes, a 4 speed transplant would be nice, but not right now.

 

[silversedan]

sounds like the governor valves are sticking, they are in an aluminum housing, when it gets warm it expands and works better, sticking governor valves are also the cause of it wanting to start out in third. the governor is in the tail housing , you should be able to get it off in the car with out pulling the trans.

 

[Cranky]

Had a trans do a similar deal with slow up shifts but always down shifted. It finally quit shifting up at all and it was the governor sticking.

 

[Greg Ducato]

I agree, it does sound like governor problems