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2012 Differential Problem?


John_RI

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Plowing today I noticed what seemed like a hesitation/skipping of power to the rear wheels, both in forward and reverse. It got worse as I continued to plow and I was barley able to get back to the garage. I've got the 2 rear wheels off the ground. When I hold the left wheel from turning I can spin the right wheel freely (nothing else rotates). When I and turn the left wheel (without holding the right wheel), the axle, axle tube and differential and right wheel turn in the same direction. Does this sound like a simple differential issue or might I have sheared key/keyway issues? Thanks, John

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Maybe the locking collar on the left axle loosened up & the gears moved away from each other. Don't know if this will fix it but you can try to tighten the locking collar. Jack the rear up so the tires are off the ground, loosen the square head set screw on the locking collar on the left axle. Push the right axle & wheel assembly inward. Slide the locking collar on the left axle inward all the way & tighten the square head set screw. Lower tractor & see if it helped. If this doesn't help maybe someone else knows. The axle keys being sheared are a possibility. Check to see if the axle tube is cracked or chunks missing also. Good luck.

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I think I've found the problem. In the pic below the hub on the right is what came off the tractor. I suspect the gears inside the differential pretty much match those on the hub. The one on the left is a potential donor and I'll have to find the differential it came out of and clean things up a bit.

IMG_0079 8x6.jpg

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Can I remove the differential (by removing the 8 bolts that hold it to the hub) without removing the axle or does the axle need to come out?

IMG_0081 8x6.jpg

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You can remove the eight inner bolts.

Unfortunately your bolts have the nuts on the outside which means that the spider gears fall loose when you pull the diff off the bolts. When you replace it you may want to insert the bolts in the opposite direction so that the nuts will be on the inside behind the flange. If you have to pull it off again it will come off as a single unit and the gears will remain in place. I set up all my diffs that way after I have worked on them for some reason.

What I have done is to get eight new bolts prior to diff removal. I then insert the new bolts in the opposite direction as I remove the diff. I will remove the nut from the existing bolt and use the new bolt to drive the existing bolt out. This keeps the gears and spacers in position as the diff is removed, and it comes off as a single unit. If you reassemble the diff with the bolts in this direction it will also go back on as a single unit and the nuts can be installed on the backside of the flange. There is no reason for the nuts to be on the outside, it works just as well with the nuts behind the flangs. I don't understand why the factory didn't install it this way.

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You should be ok on removing the bolts. I have done it in a lot hotter weather than we have now without issue. It is 20 degrees here. They probably wont slide much with the amount of grease in there in this cold. The inner gear and some pinion gears are more than likely toast. The axle doesn`t need to come out.

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I just use one extra bolt. Use it to push out the first bolt, then use that one to push out the next. ;)

Put it back together with the bolts reversed, like Rod said. It will never be a problem again.

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Thanks everyone for the help. I've got the damaged differential off and plan to use one I have that probably came off a 3012. It's been open and sitting in the garage for years so it will need a good cleaning. Hopefully I won't run into any problems. One question I do have is what type of grease should I use and how much should I use?

Thanks again, John

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You may want to replace the springs while you have it apart. They are still available at the dealer, and are fairly reasonable as I recall. That will give you what is basically a rebuilt diff, less likely for failure and good solid limited slip.

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The differential came off the axle tube fine. The donor unit was fine after cleaning the 50 year old grease out - that was a job.

combo.jpg

The inner gear was fine. I managed to get everything put back together and I didn't even have any of those pesky extra parts left over. I got out tonight to plow some more snow!

IMG_0115 640x480.jpg

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