Ford 7700 4wd wont run

[Jamsmik1]

have and old ford7700 i want to ask if anyone know whats wrong with my tractor. The tractor wont run when i engage 4 wheel drive. It seems like the front wheel is stuck.it runs wheel engaged back to rear wheel drive.

 

[Harry in Ky]

Maybe you could describe in a little more detail what happens. The tractor won't MOVE in 4WD? The front wheels don't turn, just skid? They roll okay in 2WD? None of the wheels turn, the engine stalls? Give us something to work with here.

 

[Jamsmik1]

Maybe you could describe in a little more detail what happens. The tractor won't MOVE in 4WD? The front wheels don't turn, just skid? They roll okay in 2WD? None of the wheels turn, the engine stalls? Give us something to work with here.

The tractor runs but only when 4wd is not engaged. When its engaged the front wheel looks like its jammed.

 

[Harry in Ky]

I'm not sure where to start, other than to disconnect the front axle driveline and see what changes. If it still won't roll, I would drain the oil from the transfer box and see what falls out.

 

[TractorTech]

Or, jack up the front axle and turn one side to see what happens. Listen and watch to see if it is a hub or the differential. Whe the tractor is off, the 4wd is engaged so the driveshaft will not turn.

Only other place where a problem would be is the transfer case where the 4wd driveline comes out of the rear end, but not likely