Is there a problem with my differential lock?

[Snatchface]

I'm not sure how it is supposed to act and only have the manual to guide me. The pedal is impossible to depress if the tractor is not moving. I have to be moving forward and depressing the pedal to have a chance at it engaging. Then once it is depressed, it stays down - I can't get it back up unless I rock the tractor backwards in reverse, then it pops up on its own.

The manual states that you simply have to push down at any time to have it engage and actually says that the wheels should not be spinning when you engage it. I can't get it to work unless the tractor is moving. The manual also says that you should release the lock easily without having to rock the tractor. Can someone fill me in?

PS - New (<10 hours) BX24

 

[Lockport]

I'm not sure how it is supposed to act and only have the manual to guide me. The pedal is impossible to depress if the tractor is not moving. I have to be moving forward and depressing the pedal to have a chance at it engaging. Then once it is depressed, it stays down - I can't get it back up unless I rock the tractor backwards in reverse, then it pops up on its own.

The manual states that you simply have to push down at any time to have it engage and actually says that the wheels should not be spinning when you engage it. I can't get it to work unless the tractor is moving. The manual also says that you should release the lock easily without having to rock the tractor. Can someone fill me in?

PS - New (<10 hours) BX24

That doesn't sound right to me. The pedal should exhibit the same characteristic's whether you're moving or not. Wheteher or not it is engaging is not clear. I have a section of my ditch where I can position one rear wheel virtually free of any weight and then engage the diff-lock while slowy spinning the wheel. Sometimes they are difficult to get out of engagement. In which case a backwards 1/2 revolution should rectify that, but typically a 1/2 revolution moving forward will free it up. Either way, there is something not quite right, there. Try to determine if it's even engaging. When I first got my tractor, the diff-lock was broken internaly.

 

[RoyJackson]

This topic comes up now and then...

If your tractor is in a situation where one wheel is turning and the other wheel is not (lost of traction, for example), you depress the lock. Once both wheels start turning, it's locked (pedal stays down). It'll unlock itself (pedal comes up) once there's adequate traction.

This is what the Deere 790 states:
Engage Differential Lock:
1. Stop or slow machine movement.

NOTE: Differential lock will remain engaged as long as rear wheel slippage occurs. If tires slip and regain traction repeatedly, hold down pedal with foot so differential lock remains engaged.

2. Push down on differential lock pedal.

Disengage Differential Lock:
1. Remove foot from differential lock pedal.

NOTE: Rear wheel slippage will keep differential lock engaged. Lock will automatically disengage when traction equalizes.

2. If lock does not disengage, depress one turn brake pedal, and then the other.


You can't really tell if the thing is locked or not (except for the pedal position)...until both wheels start rotating. I just work under the assumption that when the pedal comes back up, it's unlocked.

It's one of those things that you don't know if it's working until you're in a situation that you need it. I don't stop (normally, the tractor has stopped all forward travel and one tire is spinning), I just lower RPM a bit, turn the steering wheels straight and depress the pedal.

 

[Gryantaylor]

I'm not sure how it is supposed to act and only have the manual to guide me. The pedal is impossible to depress if the tractor is not moving. I have to be moving forward and depressing the pedal to have a chance at it engaging. Then once it is depressed, it stays down - I can't get it back up unless I rock the tractor backwards in reverse, then it pops up on its own.

The manual states that you simply have to push down at any time to have it engage and actually says that the wheels should not be spinning when you engage it. I can't get it to work unless the tractor is moving. The manual also says that you should release the lock easily without having to rock the tractor. Can someone fill me in?

PS - New (<10 hours) BX24

I can't say anything about the BX series but what you described is exactly how my old B 7100 works. The wheels have to be moving in order for everything to align before it slips in. I usually try and lock it just before it will be required when I'm moving slowly, both tires are turning, and I'm not stuck. When it gets stuck I'll start one tire spinning, very slowly until the lever drops in. Likewise, it will not pop out of lock until the stress on the locker is gone. Usually I just take my foot off the lever and drive normally to get it to release. Within 1 or 2 rev's of the tires it usually pops out. If I'm turning sharp or on asphalt sometimes it requires backing up breifly.

 

[KeithInSpace]

By "not spinning when engaging" is to avoid one tire spinning feverishly at 20 MPH and the other stuck stationary in the mud...then you engage what amounts to a steel shaft connecting the two wheels together. Not exactly a recipe for flowery results.

You need to be "moving" for the splines to engage and wiggle their way into place. Likewise (as others have pointed out), stress needs to be off the assembly for the splines to disengage. That is why your pedal doesn't immediately lift off the deck (just like mine).

I have only used mine a few times...4WD takes care of most situations. It works great when you're trying to do doughnuts in the cul-de-sac while racing a 400cc dunebuggy in 8 inches of fresh powder. Not that I endorse such deviant behavior. Of course I had the added advantage of being able to drop a 200# brick of snow into his path. Fun.

 

[Jimbrown]

There are dogs(notches) in the differential thay have to line up for the differential to lock. It would be pure luck if they lined up when you are stopped. You have to move slightly untill they line up and then the pedal will drop about another 1 inch. Once the stress is off of the differential it the pedal should come up. Not necessarily as soon as you let up on it. it may have to roll several feet (6 to 10 )before the pressure is released.

 

[Snatchface]

Ok thanks a lot guys. So this sounds like normal behavior then. Guess I'll just have to live with the fact that I managed to purchase something expensive and NOT have any problems with it =). Quite unexpected given my usual luck with such things.

Just for reference my last big purchase was my Accord Coupe which was about $27K. I waited 2 months for them to get one in. They called me to come pick it up. I leave work early and rush down to the dealership. When I get there the dealer has a very somber look on his face. Apparently the kid who they sent out to gas it up for me pulled out into traffic without looking and got slammed front end near totaling it. They offered to repair and sell it to me for $1K off. LOL. Needless to say I had to wait another few months for another one to come around. (They were limited production when they first came out.)

 

[KeithInSpace]

offered to repair and sell it to me for $1K off. LOL.

Bummer. And to think you could have saved $1,000. $1,000? Are they kidding? The shame is that if they fix it nice enough, an unscrupulous dealer could probably sell it as brand new since it is essentially untitled at that point.

Rest assured. Sounds like the tractor is A-OK.

 

[Berniep]

1k? That's ONE thousand dollars?
I know people who wouldn't drive a car that's been crashed if you gave it to them. Personally I MIGHT think about it if you added a zero to that discount.
You are always gonna wonder is that a shimmy, are those tires wearing properly, that door closes a little funny.

 

[Snatchface]

Yah it was completely ridiculous. I even gave them the benefit of the doubt and gave it a road test. The paint job and body work was so-so at best and the car pulled hard to the right. They hadn't even taken the care to properly align it. The salesman offered to bump the discount to $1500. At that point I drove it right back into their lot and bid them a good day.