7400 John Deere stuck in forward

[hwbarefoot]

i have a 7400 jd with a powerquad transmission. just rebuilt the transmission but only replaced clutch discs and gaskets. when i put the transmission back into tractor and fired it up the tractor was stuck in forward. linkages are correct, 1234 power shift part is working but when i put the tractor in reverse and let out on the clutch it stalls the tractor. also the only way to keep tractor from moving forward is keep the ABCD in neutral, and even the clutch want stop the tractor. its like the forward clutch pack has constant pressure but everything is trying to work. took valve body off and checked the shift valves in the valve body and everything was ok, gasket holes lined up etc. please guide me in right direction.

 

[jd110]

The only thing I can think of would be something incorrectly assembled in forward clutch. Is it possible you installed one too many disks in clutch pack?

 

[690]

It's possible to nip a clutch plate in the hub when tightening bolts of clutch drum. There is a pressure port on bottom of transmission housing saying FWD if u can put a test gauge in here and have no pressure there then it must be mechanical fault which needs stripping. Why did u take to pieces first tome

 

[MightyReek]

I remember some time ago some gaskets were wrongly labelled and caused the tractors to move forward all the times, but if you say you had the gasket holes all lined up, I guess that's no it.
Also had a buddy repairing a PQ and assembled the valves on the opposite direction and also resulted on that type of problem.

Check the pressure at FWD port like 690 said.
If you have pressure there and you're absolutely sure every valve and gasket is ok, remember you can have the valve cover or the front cover with some internal leak of pressure trough a fissure or so. It wouldn't be the first time.

If not take the rear part of the PQ and check those clutches again. When assembling it's always possible that some spring gets out of it's bed and jams everything.