2011 John Deere 85D. What could cause diminished power in drive motors/tracks?

[Serega]

I have been noticing the speed and power diminish on the drive motors/track over last few month on my 2011 John Deere 85D even on full RPMs and power mode. Everything else seams to work ok and no problems with the engine or other hydraulics. Would the problem be something in the actual drive motors or the hydraulic pump or valves?

Any advise is welcomed!
Thanks.

P.S I have 24 in steel tracks.

 

[Tones]

Seals in the rotary coupling worn allowing oil to bypass

 

[Bls repair]

^^^^^^^x2

 

[Serega]

Seals in the rotary coupling worn allowing oil to bypass

I see, Ok.. Sorry if it sounds like a stupid question.. the rotary coupling... that's inside the drive motors, correct?
Thanks

 

[uffex]

Good day Serega
You may find the attached helpful, the FAR document whist not specific to your machine the principles are the same for trouble shooting.
Kind regards
Uffex

 

[Serega]

Good day Serega
You may find the attached helpful, the FAR document whist not specific to your machine the principles are the same for trouble shooting.
Kind regards
Uffex

thank you