Broken FWD on JD 755 CT

Snowman9000 · Dec 14, 2013

I went to clear snow today. Was doing okay until I wasn't, at which time it was painfully clear I had no FWD. I tried moving the lever in and out, and it felt like it disengaged and engaged. But no go power. The last time I used the tractor, I was working it very hard, using the loader to push and move something heavy. I actually felt a little guilty afterwards, but then again this tractor has always taken a licking and kept on ticking. Maybe not this time, and it was harder than anything I've made it do.

So did I break an axle, or what? How to proceed with troubleshooting and repair? So far I've done nothing but park it and curse.

Zebrafive · Dec 14, 2013

I think I would:
1 check the linkage for 4wd. See any thing broken, sheared pins?
2 get the front axle on jack stands. With it out of 4wd try turning the drive shaft to the front axle and see if the front wheels turn.
3 with the front axle still on jack stands try turning each front wheel by hand. Not sure, but I think the opposite wheel should turn, but in the opposite direction. Or the same direction if the front has limited slip.
4 get the whole tractor up on jack stands and see if the front drive shafts turns with it running, in gear, in 4wd. Be carefull.

Snowman9000 · Dec 16, 2013

So far I've only had time to check some basics. I put the tractor on ice against a tree.

With the MFWD engaged and a rear wheel spinning, the driveshaft to the front axle is driving, but the wheels are not. So something in the front axle assy itself is broken. I found the parts explosion on the JD website. Wow, that is one complicated assembly. Not looking forward to this.

I'll jack it up and test item #3 above. If it passes that test, then I'll figure it's in the input shaft area, which I can probably tear apart and fix. If it fails test 3, I think it's off to the dealer.

Mechanos · Dec 16, 2013

Ten bucks says the teeth on the pinion gear are wiped out... as well as any number of teeth on ring gear. $$$$

4jd318 · Dec 16, 2013

Mechanos said:
Ten bucks says the teeth on the pinion gear are wiped out... as well as any number of teeth on ring gear. $$$$

Yep that is weak park on x55. We have stripped gears 3x. Try to remember to take out of 4wd when turning. I wouldn't take to dealer. It will e expensive. Not that hard to do yourself.
Gp

Mechanos · Dec 17, 2013

4jd318 said:
Yep that is weak park on x55. We have stripped gears 3x. Try to remember to take out of 4wd when turning. I wouldn't take to dealer. It will e expensive. Not that hard to do yourself.
Gp

The parts alone are $$$. Taking it to the dealer to fix would be $$$.

Snowman9000 · Dec 18, 2013

My neighbor found something online, maybe in another forum. The guy had the bolts back out of his ring gear. We took it apart, and the same thing here. Four bolts backed out, probably over time, and finally the remaining two snapped. The debris must have fallen to the bottom of the case and stayed there. There does not appear to be any damage other than heavy cosmetic damage on the back flange of the planetary assy where the bolts came out. All of the bearings and gears seem fine. I'll get six new bolts and a gasket and put her back together. I would think I should use red loctite on the bolts. ?