Rear differential "weighty" problem...need advice

[rfc143]

I've learned (with my current Kubota L5240), that at times one rear wheel starts slipping (usually because of an asymmetric load on the FEL), I can press down on the rear differential lock with the left heel. But it's quite stiff, I don't weigh that much (well, more than I'd like), such that, even with the seat belt on, the force lifts me off the seat, shutting down the tractor.

I don't think the Diff Lock force is adjustable, but short of disabling the seat interlock all together (something I prefer not to do), is there any adjustment there?

Any other ideas?

 

[Sysop]

The diff lock isn't really that stiff, or shouldn't be. It is just that it can only engage in a couple of places throughout the rotation of the diff. What you need to do is put your heel on the pedal and VERY SLOWLY let the spinning tire rotate. Some tractors only have two places in the rotation of the diff they can lock, so the spinning tire may need to spin as much as 180 degrees to line things up inside. You shouldn't need more than 10-15lbs of weight on the pedal for it to engage. Once things inside the diff line up, you will feel the pedal drop as the lock engages.

If you are applying massive amounts of pressure as it rotates, you will actually be wearing the end of the lock away. Once one of the engagement holes comes along, you'll feel it.

Once engaged, sometimes it won't want to release immediately due to binding forces inside the diff. Sometimes moving in reverse a bit will allow it to release, sometimes you need to alternate right and left braking while moving forward or backwards for it to release.

As an alternative to the diff lock, you can also use the right or left brake to stop a spinning tire and force the power to transfer to the non-spinning wheel.

 

[rfc143]

Thank you. I didn't understand how they work. I'll try what you suggest.

 

[nybirdman]

The linkage may need to be lubricated also; rarely have used mine but it doesn't take a lot of pressure to engage(L4240 Kubota so very similar tractor).

 

[George2615]

I second nybirdman's idea to lube the diff lock linkage. I had the same thing happen on one of my tractors from lack of use. The linkage froze up (rusted?) where it goes into the trans. I could put my full weight on it and it would not move. I sprayed it in penetrating oil several times a day for several days. Then had to tap the pedal down with a hammer and pry back up with a bar. It took several tries spraying on each movement. Once it freed up I sprayed it once a week and made sure to use it more often. Very possible your could need lube also.

 

[teg]

Personally, I think you need more counter weight on the three point hitch so your back wheels don't lose traction in the first place. :2cents:

 

[Grandad4]

Personally, I think you need more counter weight on the three point hitch so your back wheels don't lose traction in the first place. :2cents:

I'll second that idea! If you're forever needing to lock up the back wheels, it indicates there's not enough weight in back. You can add fluid to the rear tires as well as put something heavy on the 3 point hitch, with the attachment in back taking first priority. The more weight you have in back, the more you can lift and besides, it makes tractor operation safer.

 

[rfc143]

I'll second that idea! If you're forever needing to lock up the back wheels, it indicates there's not enough weight in back.

That's not the issue. I always carry an implement on the 3pt; I have loaded tires, plus another 700+ lbs of rear wheel weights. I work on often wet hilly terrain, but don't lose traction all that often. I'm inclined to go with the concept that I don't use it enough, and it's gotten stiff/rusty.