904 trans issue(updated)

[markmopar]

We have a '76 Cordoba 360/904. The mainshaft snapped so we had the trans rebuilt(not professionally, friend of a friend thing).
When it's cold the shift points are very high. The warmer it gets, the lower the shift points are. When fully up to temp it seems to shift normally.

Any ideas where the problem might be?

[John_Kunkel]

The person who rebuilt it may have cranked the line pressure adjustment way up. Only a gauge on the line pressure test port will tell.

[markmopar]

What should the line pressures be?

[John_Kunkel]

Around 45-50 psi in Drive idling and 90 psi max at WOT in Drive.

[markmopar]

Thanks. When it warms up a bit, I'll do a check. 

[markmopar]

All I had was an 80psi oil gauge.
Hooked it up today and had nothing at idle in neutral. Put it in drive and it no response until I touched the gas, then it shot up to where 150 or so would be on the dial!
Reverse showed nothing, even on the gas. Back to neutral, went back to nothing.

[c00nhunterjoe]

Wbat port are you using

[markmopar]

Wbat port are you using

The line pressure port on the right side of the trans case roughly in the middle.

[c00nhunterjoe]

Park and neutral will be 0. It wont build any pressure at all in drive until you raise the rpm?

[markmopar]

Right, No pressure until I raise the RPMs. Then it shoots way up.

[John_Kunkel]

All I had was an 80psi oil gauge.
Hooked it up today and had nothing at idle in neutral. Put it in drive and it no response until I touched the gas, then it shot up to where 150 or so would be on the dial!
Reverse showed nothing, even on the gas. Back to neutral, went back to nothing.

Well, you need a gauge that will actually show correct pressures over 80 PSI but, if the pressure actually is 150, then somebody has been messing with the regulator.

[c00nhunterjoe]

John, shouldnt there still be line pressure at idle in gear? Something is wrong if it shows 0 until he build wheel speed?

[John_Kunkel]

Yes, as stated, you should have at least 40-50 psi at idle in Drive.