Kubota B2920 rear drive problems

   / Kubota B2920 rear drive problems #1  

jjmjones

Member
Joined
May 24, 2010
Messages
31
Location
Western Massachusetts
Tractor
Kubota B2920
My B2920 has rear chains on Ag tires. Using with a blade and bucket to move some snow. I am noticing a dramatic decline in the ability of the rear wheels to provide any help with moving the machine. It is in "4 wheel" and I am using the differential lock. The fronts are spinning like mad and rears do very little. I've tried to isolate the rears by switching to "2 wheel drive" and the rears can barely move the machine with little or no load. Nothing obvious to me is wrong. Am I missing something simple here? Trying to avoid bringing to dealer.
 
   / Kubota B2920 rear drive problems #2  
It shouldn’t have any effect, but what is the result if you don’t lock the rear differential?
 
   / Kubota B2920 rear drive problems #3  
Is it HST - Hydrastat? or Mecanical 4 wheel?
 
   / Kubota B2920 rear drive problems #4  
No bad noises? I don't think you are missing anything simple unfortunately. If no rear wheels are moving even with diff lock engaged you've probably broken the rear diff, since you still have the front drive. I wouldn't run it more than you have to, to get it to the dealer, as there could be metal in the hyd fluid.
 
   / Kubota B2920 rear drive problems #6  
Could be something as simple as a roll pin slipped out of the carrier, or it could be more complicated. If still under warranty, the dealer should be the one to open it up. If out of warranty, you lose nothing but some oil and gasket material by opening up the differential & taking a look
 
   / Kubota B2920 rear drive problems #7  
Sounds like it's hydrostatic. Must not be getting the same oil to rear.
 
   / Kubota B2920 rear drive problems
  • Thread Starter
#8  
It shouldn’t have any effect, but what is the result if you don’t lock the rear differential?
I have HST. NO change in the rear when lock is on or off. No unusual sounds. Probably should take a look.
 
   / Kubota B2920 rear drive problems #9  
Rear tires possibly slipping on the rims??

Mark the wheel and tire. see if the line moves on either side. It is sometimes hard to see this problem when actually driving the tractor.
 
   / Kubota B2920 rear drive problems
  • Thread Starter
#10  
Bingo sd445dan. I marked the tires-put under strain and the wheel is moving but the tire is not. Good call. I notice a small nick on the rim and some leaking of the beet juice. I'm going to hope if I take the tire off, do any repair on the wheel etc that this will be the solution.
 
 
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