Workmaster 55 Differential lock

[jsmcobra201]

We just took delivery of a brand new NH Workmaster 55 2WD this weekend and immediately put it to work with some box blade work and running our shredder. One of the areas I had to mow required me to cross a creek. Since this tractor was a 2wd and the creek was sort of steep I decided to play it safe and step down on the diff lock while crossing the creek. The tractor had no problems, no wheel spin at all, she just lugged right up the creek. Now here is where it gets interesting, after crossing the creek I noticed that it was hard to turn, the front wheels would just "plow" forward before finally turning the tractor. I also could not operate the R and L brakes independent of one another. So that has me thinking that the diff is still locked. On other tractors I have operated, (JD and Massey's), the diff lock automatically disengages when you take your foot off of it. I assume NH should work the same way?

By the time this started happening I was almost finished with my mowing, the air temp here in SE Texas was getting close to 100, and with no breeze to speak of down by the creek, I pretty much had to shut down, shower up and head home.

Obviously the tractor is still under warranty (I've got just a little over 10 hrs on it now) and I know our dealer is one of the more reputable dealers around (WC Tractor in Brenham) but I'd rather not have to take it in if it's something simple. Any ideas why the diff seems to still be locked? Is there some sort of way to release the diff lock that I am not aware of? Could I maybe have run over some sort of stick/ limb etc that wedged itself in some linkage somewhere that won't allow the diff to un-lock? -- just guessing here guys, I'm no expert though I didn't see anything obvious. Of course if I can't fix it, then I will have the dealer check it out, I know a locked diff is not good for long term operation.

I'll take a look at it the next time I am out on our property, but the bad thing is I live about 95 miles away from our property and tractor. It will be the end of June before I can get out there again.

Other than this complaint, I'm loving the Workmaster 55.

 

[Robert_in_NY]

How long did you use it after pushing the dif lock? One trick I have found is that when I have had the lock not kick out was to put the tractor in reverse. It usually pops out without any issue.

I only ever recall using the dif lock on my 45 twice without any issues at all.

 

[jsmcobra201]

How long did you use it after pushing the dif lock? One trick I have found is that when I have had the lock not kick out was to put the tractor in reverse. It usually pops out without any issue.

I only ever recall using the dif lock on my 45 twice without any issues at all.

I bet I ran it for another 20-30 min after I noticed it locking up. I know I had to reverse it a couple times when I used the loader to push brush out of the way. I even shut it down completely to check oil levels, transmission levels, etc. I let it sit for another 30 min as I got cleaned up and packed up, then fired it up to put it away and noticed it was still locked. I watched my father put it away and you could easily see that the inside rear tire was turning at the same rate as the outside rear tire when making a turn. That pretty much tells me that somehow the diff is locked together.

I hope it's something simple. From what I understand a diff lock isn't all that complex so there shouldn't be much that can actually go wrong-- especially with only 10 hrs on it. I may call my dealer today and see what they say.

 

[DieselMonk]

If the differential is still locked and you can't get it to unlock, try to lift somehow the rear axle with a jack or backhoe or something and rotate each rear tire back and forth by hand. That should get the bound up locker free.

 

[BeeferMan]

Something's not right. Assuming it's a mechanical device that functionally eliminates the differential, that lock should release as soon as the forces on the two axles equalize - and that should have happened multiple times in running the tractor 20-30 minutes. Broken spring, jammed linked, or something like that. If you called the dealer I would imagine he'd send someone out to have a look before hauling the tractor all the way back to the shop.