TL90 driveline issues?

[dntfxr]

Can anyone help me out with a TL90 that the rear end isn't pulling? It's stuck in 4wd which I've read is common but with the rear end not pulling I can't figure out where to start. Does anyone have any suggestions on what might be the issue? Thanks for any help

 

[Harry in Ky]

Not sure if "stuck in 4WD" is such a common issue. I see the 4WD light on the dash staying on due to a defective pressure switch as much more common. As for the rear drive, I'd suspect a broken pinion shaft in one of the rear axle units. If you jack up each rear wheel, one at a time and try to rotate it, neither one should turn unless the the other three turn as well. If any one turns independently, that would indicate it's not connected.

 

[RickB]

Not sure if "stuck in 4WD" is such a common issue. I see the 4WD light on the dash staying on due to a defective pressure switch as much more common. As for the rear drive, I'd suspect a broken pinion shaft in one of the rear axle units. If you jack up each rear wheel, one at a time and try to rotate it, neither one should turn unless the the other three turn as well. If any one turns independently, that would indicate it's not connected.

A broken half shaft can't be diagnosed that way. One broken shaft will allow either rear wheel to turn without turning the front wheels. Differential action. Test for a broken half shaft by driving the tractor with the differential lock engaged. One rear wheel will be powered, the one with the broken half shaft will not be. Might consider disconnecting the front driveshaft for these tests if you haven't sorted that problem out first.

 

[dntfxr]

Ok thanks guys that gives me a place to start. I'd discovered that on these models when the 4wd actuator quits working it stays in 4wd, I guess it's not real common but I'd read several threads about it on another board. I think that part is an easy fix, but the rear end sounds different. I'll start there guys thanks again