Differential Lock Question

[CharlieTR]

I have notice a few times by reading various threads that my tractor is not exactly the norm when it comes to some features and mostly the controls are different from almost all new tractors. It is my first tractor and only tractor so far. I pretty sure I would have to be taught the controls on any other tractor before I could use it.

Anyway... On my Long LongTrac 520 (2002 year model) there is a Diff lock peddle. I press the peddle when one wheel spinning in mud and never fails to get me out. The manual says to make sure you do not attempt to use while turning, and must be trying to go straight. Lately I have notice that it does not disengage when I think it should, there is a long delay and if I do turn, I really notice it's engaged. It really forces some strain on the transmission.

Do most tractors have this feature?
Is there any special maintence for this diff lock? (Not is my very skinny manual)
Maybe I should not expect it to disengage when the peddle is released. ??

 

[jwstewar]

Sounds to me like you have been the fork that engages the diff lock pedal. Probably by engaging it while spinning one of the tires too quick. It should disengage when you remove your foot from the pedal. Sounds to me like it is time for a trip to the dealer for some fixin'.

 

[thcri]

If you have any linkages on it make sure they are greased well. My lever when not used much will stick down, I have to reach down and pull it back up. Even then sometimes it will not come up and alls I have to do is back up or turn to get it back out. I think you can turn your steering wheel once you have it locked in and trying to get back out they don't want you turning while engaging. Check your manual closer and call your dealer as I am not sure of your brand and how it actually works.

murph

 

[JerryG]

The manual says to make sure you do not attempt to use while turning, and must be trying to go straight. Lately I have notice that it does not disengage when I think it should, there is a long delay and if I do turn, I really notice it's engaged. It really forces some strain on the transmission.

Do most tractors have this feature?
Is there any special maintence for this diff lock? (Not is my very skinny manual)
Maybe I should not expect it to disengage when the peddle is released. ??

There will be times when you push the pedal down that the gears don't engage until the tractor rolls a little. These are square cut gears and they have to line up before they will engage. I don't know if this is the delay you are speaking of or not but it is normal. When you let up on the pedal, the gears will disengage if the wheels are moving straight and the are not in a bind. If one wheel is on hard ground and the other is in mud or one is on a bank or ditch and the other is on level ground then it won't disengage because that causes a bind between the two wheels. If you are turning they will also be in a bind and won't disengage. There are times when you may need to lubricate the linkage from the pedal going into the transmission housing.

 

[Soundguy]

Good info here. I'll also re-iterate what another user touched on.. make sure you wheels are spinning -very- slowly when you engage the diffy lock.. ( not fast.. )

Soundguy

 

[kwolfe]

I am not a mechanic, however I have heard others say that you should only have the diff lock engaged when going straight as it will put undo strain on the driveline if you are turnning a lot with it engaged.

Think about it this way. With it locked, both wheels want to push straight at the same rate. If you are turnning, the insdie wheel wants to naturally spin slower than the other.

I would also echo the others posts that say go SLOW when engaging the diff lock.

 

[jinman]

Charlie, on my New Holland tractor, the Operator's Manual specifically says the differential lock pedal only needs to be pressed once and it will stay engaged until a locked differential is no longer required and then release by itself. I think this is saying that as soon as the driveline is not in a heavy load, the pedal will pop back up.

That's exactly as it works on my tractor. Yours may be the same or it may be binding as others have suggested. Either way, it should only be engaged for a short time and turning should be avoided as you stated. I would depress the pedal when I was not in a heavy load (such as slowly moving on a flat surface) and see if the pedal pops back pretty quickly. If not, a little lube may be needed.

 

[N80]

That's the way it works on my Kubota as well. It stays locked while under load and then pops out when no longer under load.

 

[George2615]

Mine is also supposed to release when your not pushing down on it. I noticed it did not release once when I took my foot off the pedal so I added a return spring to assist pulling it back up when I take my foot off. If its binding you may find it will release easier if you stop and back up a little. Keep the linkage well lubed also.

 

[wushaw]

My Kubota L2800 works as N80 & Jinmans does, It will release when lock is no longer needed..usually in a few feet when both rears are back on tera firma.