Kubota B2920 rear drive problems

[jjmjones]

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.

 

[seville009]

It shouldn’t have any effect, but what is the result if you don’t lock the rear differential?

 

[ljjhouser]

Is it HST - Hydrastat? or Mecanical 4 wheel?

 

[IndyIan]

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.

 

[5030]

Unless you are very mechanically adept, I'd say it's dealer time.

 

[alexpops]

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

 

[Jimbo16720]

Sounds like it's hydrostatic. Must not be getting the same oil to rear.

 

[jjmjones]

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.

 

[sd455dan]

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.

 

[jjmjones]

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.

 

[ruffdog]

What air pressure are you running?

 

[ljjhouser]

That would be a fantastic outcome. Good find and I bet you are feeling better about the whole situation. Good.

 

[jjmjones]

The tires on the rear of my B2920 are 12-16.5. I have liquid ballast. The manual indicates 40psi. Sound right to folks? I need to check what the psi currently is. There is no sign that anything is amiss- is that because the tire has ballast in it and it would not show low pressure?

 

[ruffdog]

It is common, especially during cold weather, for filled tires to be too stiff for an owner to notice low air pressure. If they are low, fill them to the correct pressure and get through the winter.

 

[Henro]

The tires on the rear of my B2920 are 12-16.5. I have liquid ballast. The manual indicates 40psi. Sound right to folks? I need to check what the psi currently is. There is no sign that anything is amiss- is that because the tire has ballast in it and it would not show low pressure?

40 PSI??? That doesn't sound right to me.

I run the liquid filled tires on my B2910 at around 12~15 PSI. Less sometimes when I don't check them for a couple years...and they somehow lose a bit of pressure.

 

[jjmjones]

Funny the tire in question registered 65 PSI. The other one registered nothing and gurgled when I put air in it. the brain is starting to hurt