Yeah, I was quoted 15 - 20 hours AFTER I already had it removed. $50 hour. This was not at a Kubota dealer but a reputable tractor repair shop with 3 ex Kuboata techs, I think the dealer must be quite a bit more per hour, I didn't ask. OUCH. So I decided to just do it.
I am mechanically inclined and have all the tools, including mentally and physically, I was a Mercedes, GM, Nissan, ASE master technician in a former life, 13 years ago! I did a lot of transmissions, automatic and manual, so I wasn't afraid. Never even bought the service manual, but used the kubotabooks.com for parts. Although I did finish it last night I could not lift it off the bench, I need help for that!
How it happend I'm not sure. I know all about the "rules of diff lock engagement" I didn't use it on high traction surfaces, never engaged it while wheels spinning, so who knows. I have used it a lot though, BX's are not high on traction in my opinion. I run turfs in the summer, ags in winter and when I know I am going to be digging or using the FEL. Both sets of tires have solution in them. I never thought the BX had enough weight/traction to put enough stress on the diff lock to break it. Obviously wrong! I think maybe the fork broke then the diff lock would not fully dissengage? Based on the amount of wear from the broken parts it has been this way a while. Last summer my daughter and wife started to mow the lawn for me, so I didn't drive it much, but I did do all the snow plowing this winter and didn't notice until the first mowing. Then the diff would lock up about 1/3 into a turn. Funny thing, when you see the broken parts, is that the diff lock would lock up correctly when the pedal was pushed. Once in a while, about 6 times I had heard a loud clank, the first time or two I thought it was the three point arms or something back there, I had a 5' rear blade on. Then my wife mentioned when she spread 30 yards of bark that she heard it also and it sounded to her like she ran over a shovel. I tore it down that night not wanting to do more damage. I saw a few other posts on this and it wasn't cheap.
I can't remember all the dirt and gravel this thing has moved but I know it is at least 8-12 15+ yard truck loads of topsoil, sand, crusher dust etc. I put in about 1300 sq feet of paver patio etc and of course put in my lawn on 2.5 or so acres. Not to mention all the times I've helped the neighbors and family. Probably 200+ yards of bark mulch moved, oh yeah, probably about 6 FULL cords of trees dragged out of the woods.
I don't have any hard feelings, I do take care of it and it has worked probably harder than a BX was meant to, but I can't see a bigger tractor on my lot, not anymore now that the pond and all landscaping has been done.