case 855D

[kermit bryant]

My loader stopped moving. Working fine when last parked. I had been chasing leaks for a while on the torque converter housing , so I know its been low on fluid at times. pulled the floor pans, there is a grinding noise coming from the housing. charge pump is holding pressure, hydraulic pump is working but drive shaft stops turning when i put it in gear. drive yoke seems Ok. thinking might have lost something in torque converter or splines on short shaft??

 

[alrman]

Welcome to HEF @kermit bryant
Can you clarify which housing the grinding noise is coming from?

If the driveshaft stops when put into gear, and the machine is stopped, not moving, that is normal.
Question is, how fast is the driveshaft spinning? Fast as a blur? Or slow and docile?

You haven't mentioned if oil level is ok?
Did the park brake work on this machine? Has it released properly?
Brake pedals feel normal?

 

[kermit bryant]

oil level is good. the parking brake is not hooked up. cable was missing when I got it. the noise is coming from the front housing where the charge pump and hydraulic pump is mounted. the driveshaft spins pretty fast but doesnt look like motor rpm. the driveshaft stops when put in gear with no brakes applied. brakes feel normal

 

[alrman]

Hmmm.... If the loader hydraulics are still working, the convertor is still turning with the engine.
What is the transmission pressure reading?
Does the pressure come up as soon as you start the engine?
The noise you are hearing could be cavitation - air being pulled into the transmission charge pump suction hoses.
If they cavitate bad enough they won't drive too well, the transmission oil will also be aerated (foamy).

Are you in snow country? Tracks frozen?
I imagine it wouldn't be that cold in Alabama.

 

[kermit bryant]

Hmmm.... If the loader hydraulics are still working, the convertor is still turning with the engine.
What is the transmission pressure reading?
Does the pressure come up as soon as you start the engine?
The noise you are hearing could be cavitation - air being pulled into the transmission charge pump suction hoses.
If they cavitate bad enough they won't drive too well, the transmission oil will also be aerated (foamy).

Are you in snow country? Tracks frozen?
I imagine it wouldn't be that cold in Alabama.

no snow. So does the torque converter stall or disconnect from the drive shaft when brakes are applied. I do not understand the relationship between the engine turning and the driveshaft not turning. charge pump pressure is around 300 psi

 

[alrman]

When you engage a gear, is there a clunk in the drivetrain?
Does the driveshaft stop suddenly?
Any track movement whatsoever?
Does this machine have anything mounted to the rear PTO? Winch maybe?

 

[kermit bryant]

not a sudden stop like something locked up but pretty quick. no movement at all. nothing attached to rear or pto. Im going to put a larger scale gauge on charge pump and see if pressure is higher than 300PSI. manual says should be around 250, maybe pressure regulator is plugged. not sure high pressure would cause my problem.