4210 "Locked" Rear Wheel/Diff, No Apparent Neutral

[D C]

In the snow today, the left rear wheel turns and the right rear doesn't move. Hmmm.... use the locker pedal and it moves reluctantly.

Pulled it in the garage, jacked up the rear.
Turn the left rear tire, the right turns the opposite way...EVEN IN NEUTRAL.
My son and I on opposite sides and we cannot get the wheels to turn in the same direction.

Rear still elevated...
Hop on, hit forward, no movement. Try reverse, no movement. Definitely in neutral.
Shift to A, left rear turns, right sits still
Engage locker pedal, they both turn and the engine bogs

Try the brakes...
Left brake on, can't turn right wheel in neutral
Right brake on, can't turn left wheel in neutral

4210 mFWD eHydro, roughly 900 hrs
Hydraulic oil is full, not dirty or due for a change
Flashing trouble code 13 (mis-adjusted/faulty parking brake switch)

Any ideas??

 

[herm0016]

In the snow today, the left rear wheel turns and the right rear doesn't move. Hmmm.... use the locker pedal and it moves reluctantly.

Pulled it in the garage, jacked up the rear.
Turn the left rear tire, the right turns the opposite way...EVEN IN NEUTRAL.
My son and I on opposite sides and we cannot get the wheels to turn in the same direction.

Rear still elevated...
Hop on, hit forward, no movement. Try reverse, no movement. Definitely in neutral.
Shift to A, left rear turns, right sits still
Engage locker pedal, they both turn and the engine bogs

Try the brakes...
Left brake on, can't turn right wheel in neutral
Right brake on, can't turn left wheel in neutral

4210 mFWD eHydro, roughly 900 hrs
Hydraulic oil is full, not dirty or due for a change
Flashing trouble code 13 (mis-adjusted/faulty parking brake switch)

Any ideas??

1. the speed ranges are well before the differential and this behavior is totally correct. because of the ratio and helical cut of a pinion gear it will take a huge amount of force to spin it from the wheel vs the transmission. when you are spinning the left, the right is driven by the spider gears in the opposite direction, and it is not spinning the carrier in the differential. the carrier is what is connected to the transmission with the pinion gear.

see:

2. normal save for the engine bogging when the locker is applied.
3. totally normal, the speed range has nothing to do with the differential operation. see explanation at 1.

It sounds like the right brake may be tight. but a full understanding of how it works will be beneficial to your diagnosis.

parking brake is fully off correct?

sounds like the parking brake can be a source of problem for these:

4210 brake issue

www.greentractortalk.com

 

[D C]

Thanks, I'm very familiar with open differentials.

What is absolutely NOT normal is that the wheels will not rotate in the same direction or independently while in neutral. With the pinion shaft disconnected (i.e. neutral), any 2 of the 3 "ins & outs" should be able to rotate together. Turning them in the same direction should result in the neutral/disengaged pinion shaft spinning freely.

 

[herm0016]

the final drives on a tractor are HUGE ratios. 5 to 1? something like that, then you must also overcome the ratio at the differential. it would take 10 of you to spin the thing from the wheel side. think of the ratio on a car, and the RPM, then think of the same on your tractor. the ratio in the transmission is not all that different, the difference is the final drive ratio.

if the reduction was all in the transmission, it would be twice the size at least.

 

[D C]

1. the speed ranges are well before the differential and this behavior is totally correct. because of the ratio and helical cut of a pinion gear it will take a huge amount of force to spin it from the wheel vs the transmission. when you are spinning the left, the right is driven by the spider gears in the opposite direction, and it is not spinning the carrier in the differential. the carrier is what is connected to the transmission with the pinion gear.

see:

2. normal save for the engine bogging when the locker is applied.
3. totally normal, the speed range has nothing to do with the differential operation. see explanation at 1.

It sounds like the right brake may be tight. but a full understanding of how it works will be beneficial to your diagnosis.

parking brake is fully off correct?

sounds like the parking brake can be a source of problem for these:

4210 brake issue

www.greentractortalk.com

That brake issue might just be what's going on.
I took a closer look at it and noticed that the right brake really doesn't have much effort to fully depress, while the left one does.
With the rear off the ground, the left side has what I would call a normal amount of differential lash. Maybe 1-1/4" at the tire tread. The right side only has around a 1/2" and is definitely not engaging anything else before it stops.

I'll look for wherever the brake shaft goes and lube liberally.

Thanks!
Dave

 

[rScotty]

Thanks, I'm very familiar with open differentials.

What is absolutely NOT normal is that the wheels will not rotate in the same direction or independently while in neutral. With the pinion shaft disconnected (i.e. neutral), any 2 of the 3 "ins & outs" should be able to rotate together. Turning them in the same direction should result in the neutral/disengaged pinion shaft spinning freely.

Are you sure about "NOT normal"?
Maybe it is worth trying the same test on your manual shift car or PU. Just jack up the back, put it in neutral, and turn one wheel. Which way does the other one rotate?

 

[D C]

Are you sure about "NOT normal"?
Maybe it is worth trying the same test on your manual shift car or PU. Just jack up the back, put it in neutral, and turn one wheel. Which way does the other one rotate?

Very sure. When both are turned in the same direction, the pinion/input shaft will rotate if the vehicle is in neutral.

 

[D C]

It was a stuck brake shaft on the right rear. Some PB Blaster, the butt end of a 5lb sledge, and an assistant on the tractor did the trick. Took turns hitting the brake, and hitting the bellcrank to release the brake. Lubed it up and it seems to be ok now.

Still wondering why the pinion wouldn't turn. Must be something in the trans/coupling that creates drag even when in neutral. I did notice that in neutral, the un-stuck rear wheel would turn. No torque on it to speak of and could be stopped with a finger.

 

[ruffdog]

It was a stuck brake shaft on the right rear. Some PB Blaster, the butt end of a 5lb sledge, and an assistant on the tractor did the trick. Took turns hitting the brake, and hitting the bellcrank to release the brake. Lubed it up and it seems to be ok now.

Still wondering why the pinion wouldn't turn. Must be something in the trans/coupling that creates drag even when in neutral. I did notice that in neutral, the un-stuck rear wheel would turn. No torque on it to speak of and could be stopped with a finger.

Yes, lube up all the control shafts going into the cases as they tend to freeze up. Also, hydro-static transmissions will NOT freewheel in neutral like you had done with a car/truck.

 

[herm0016]

glad your problem is solved.