Repair diff lock on JD 4100

[Jon E]

I have a 1999 JD 4100 with HST. By doing the stupid thing and trying to engage the diff lock while the rear wheels have been spinning, I have stripped gears or broken something in the differential. So now the diff lock does not work any longer.

My local dealer is basically refusing to do the work. He has not outright said 'no, but he's one of those guys that tries to avoid major service work because it ties up his very small garage bay. He's basically whining about how much work it will be and how difficult it will be.

Well, my brother has about 2500 square feet of heated high-bay garage and a full complement of tools and equipment to do the work. I just don't know how. I would like to buy the parts, tear it down and do it myself with his help (he runs a 4wd performance shop). How difficult is this job? And how much could I expect to be spending on parts for the repair? I am a novice when it comes to this kind of thing but I learn fast and am mechanically inclined so I think that with a service manual and the right parts, I can repair the diff lock myself.

I am also going to put a big sticker on the hood that says "DO NOT ENGAGE DIFF LOCK WHILE WHEELS ARE SPINNING!".

 

[RoyJackson]

Before you tackle this job, I suggest you call the closest Deere dealership and see what's involved and get an estimate on parts costs. If you don't have a tech manual...well, good time to buy one.
The good news, of course, is you had someone with mechanical knowledge, the tools and a good place to do the job. That can save you a lot of money (except for that bottle of vintage, single malt scotch for your brother!!)

 

[micky967]

did you manage to fix this? i have a JD 4100 HST tractor and diff lock doesn't engage anymore or slips back up after 10 seconds. Going downhill it just steams down out of control and its going to cause serious injury or death.