Bobcat 853 drive motor whine/pulls to right

[Mitch500]

Hello,

Recently got my newly acquired 1995 bobcat 853 going after a bunch of maintenance/unknown condition.

I've changed hydraulic filters, case drain filters and fluid, repaired most leaks that I could find.

My question is when I push both levers forward it wants to slightly turn to the right when going straight. There is also a minor hydraulic whine coming from the right side drive motor. The sound isn't noticeable/can't be heard if you slightly or slowly drive forward straight, but if you push the levers all the way forward or turn one direction the right side motor whining can be heard. This is forward and reverse.

I did notice some minor blue plastic material in the right side case drain filter which I was unsure of, but now thinking about it maybe it's a piece of a seal?

How should I proceed with this? Should I pull the drive motor and dissemble it and inspect the seals/metal components for wear? Can a damaged seal cause the whining from high-pressure leaking into a area In the drive motor it's not supposed to be leaking too?

Photo of case filter with blue material on it. No metal in filters.
Thanks!

 

[Old_853]

I think I remember a blue O ring inside the drive motor. The seal kits are inexpensive and it's fairly easy to rebuild. There's youtube videos of similar models, but not an 853 I could find. That's likely the culprit. What do you run for hydraulic fluid out of curiosity? They came with motor oil, many people switch over to AW-46. I often wonder how well they mix.

 

[Tlawdogg]

What brand drive motors? There are several different sizes and colors of O-Rings in them.
Here is a drive motor off 99' 863f. You can see the crumbles of what was an O-Ring. It was in my case filter.
PS my drive motor lacked power on one side. In both forward and reverse. That was the bad one for me. Only once it was warmed up ( Hyd. Fluid)

 

[wateka]

If it's pulling in one direction, the service manual suggestions are:

1. The steering linkage needs adjustment.
2. The hydrostatic pump has damage.
3. The hydrostatic motor has damage.
4. The tires do not have the correct tire pressure.
5. The tires are not the same size.

As old as our machines are, the steering linkage is worth looking at. I had to replace both the cables on my 853 and then readjust to both find neutral and eliminate any wheel creep.

 

[Mitch500]

If it's pulling in one direction, the service manual suggestions are:

1. The steering linkage needs adjustment.
2. The hydrostatic pump has damage.
3. The hydrostatic motor has damage.
4. The tires do not have the correct tire pressure.
5. The tires are not the same size.

As old as our machines are, the steering linkage is worth looking at. I had to replace both the cables on my 853 and then readjust to both find neutral and eliminate any wheel creep.

I have no wheel creep sitting idle. Tires are brand new and pressure is all the same.

I did notice some blue rubber material in the case drain and now that I recall there was some hard plastic/beach glass looking stuff in it as well that looked like a dried up seal.

I'm going to pull the right drive motor and do a little tear down and see what's up. The sound is definitely coming from the right side between the wheels so that tells me something is up with the drive motor.

Also I was driving over ice and snow so it's possible the left side had more grip than the right so this could be skewing my results. But regardless there is a minor sound coming from the right.

Thanks all.

 

[wateka]

Your post reminded me to finish putting my overhaul pictures together. The below may be helpful during your overhaul.

Thread 'Final drive motor overhaul for Char-Lynn 114-1064-005'
https://www.skidsteerforum.com/threads/final-drive-motor-overhaul-for-char-lynn-114-1064-005.120502/