7700 need help with no drive

[mercury65]

tractor stopped moving in field , checked hi low presure found it at 120 psi in hi and low , resealed hi low and installed new clutch and presure plate while i was in there , reassembled all and tested , same problems , replaced hyd pump with new one and retested , same problem , unit will just pull itself , touch the brakes and the unit stops , what am i missing

 

[souNdguy]

have you checked the ring/pinion gear and axle shafts?

soundguy

 

[mercury65]

i removed the hyd pump and put a small pipe wrench on the shaft , i was able to roll the tractor with this , and when i held it there was no way i could roll the tractor

 

[mercury65]

is there a spline at the rear end of the transmission somewere

 

[souNdguy]

do hyds work?

how did the input shaft look?

soundguy

 

[RodinNS]

I'd be checking the dual power control valve. Mabey some trash in it. There may have been an inlet line screen in that one too. I don't know... but if there's a screen in the valve... it could be blocked and you'd still have pressure when you test.
Another option is that you have some problems in the clutches... plates stuck/binding and will not engage.. or a stuck piston, etc.
I highly doubt that the problem is in that rear axle.
Your pressures are none too good either but they will certainly cause locomotion without a load.

Rod

 

[mercury65]

yes the hydraulics are working , i should have mentioned i installed a new hydraulic pump due to the lower than nornal presures , i have also repaired a leak in the pto brake piping , i had a cracked fitting feeding the brake , i have since resplit at the clutch and removed and disassembled the hi/low to see if i had done somthing wrong , i got a retired ford guy to come out and go throught the hi/low with me thinking i was missing somthing , me bench tested the unit and than reassembled and air presure checked it in the tractor , i am as we speak reassembling to test , ill let you al know

 

[souNdguy]

good luck!

soundguy