Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors


7000 series differential question

Recommended Posts


I have a 7016 I use just for plowing snow. I noticed only one tire is spinning and was wondering how to fix this. This style diff has always worked well for me and it's been years since I have had one apart.(can this style diff be locked? Most of my plowing is straight line)

Share this post

Link to post
Share on other sites

It's a limited-slip diff so as far as I know it cant be locked but may need adjustment. The proceedure is in the owners manual. sm01

I've never had to do one. If nobody gives you the specs here I can send you the manual if you PM me your e-mail address.

Share this post

Link to post
Share on other sites

The later style diffs are not "adjustable" like the old tractors with the set screw. However, the springs behind the pinions could be shimmed for more preload, which would make the limited slip "stiffer". If you have a lot of wear inside on the ends of the springs and gears, you could be down on preload. Or any broken springs could cause a lack of limited slip/posi. I have heard of people locking them up, but the only way I see it causes poor tooth coverage from one gear to the next. Some of the pullers out there might have some input on locking one up. Tim

Share this post

Link to post
Share on other sites

I prefer to shim the diff if I need better traction. I did my first shimmed diff 25 years ago when I was tractor pulling with a Simplicity. I started out with a lock diff, but it is very difficult to turn the tractor when on a surface with lots of traction. I came up with the shimming of the springs, which dramatically increases the traction buy still allows the tractor to turn on high traction surfaces such as asphalt.

To shim my diff I just used regular washers that I bought at a hardware store. If I remember correctly, I had to grind down part of the outer diameter so that the washer would fit inside the radius of the diff housing. One washer under each spring gave me enough friction to tighten the lug nuts with one wheel on the ground and one in the air.

If you want to lock the diff, that is very easy. There is a gear on the axle that goes to the left wheel. The gear teeth are off center since one side of the gear is used as a spacer between it and the gear on the right side hub. If you just flip this gear to put the spacer portion toward the left side instead of the right. This will move the gear teeth inward so that they intersect both the spider gears on the left side and the ones on the right side. In this configuration the spider gears cannot turn, so the diff is locked. The good thing is that it can easily be put back to the stock position, since no parts are modified.

Share this post

Link to post
Share on other sites

Thanks Rod, I had a 3112 many years ago that had that gear turned around to lock the rear. I might try it, if I can't steer it enough I will just shim it. I usually just use my walk behind snowblower but I broke my left leg hiking thanksgiving morning. I haven't been on here in years, glad I remembered my password.

Share this post

Link to post
Share on other sites

If you use the tractor for mowing I don't think I would

lock up the rear end, as you'll tear up your lawn.

I have all B series tractors, that have the two bolt on the

Right hand hub, so all I have to do is crank them down a little.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Who's Online (See full list)

    • DaveTenney
    • SmilinSam
    • abu507
    • rokon2813
    • AllisLaporteb12
  • Today's Birthdays

    1. Carchief
      (57 years old)
    2. Geoff
      (56 years old)
    3. mohrds
      (51 years old)
  • Recent Status Updates

    • SonOfCreepfeed


      Thinkin' about this old girl.

      · 2 replies
    • Dean McFadden

      Dean McFadden

      Good morning peeps! I’m always searching for helpful information with my AC collection. Hope to find out new information and pass on my own experience in restoration. Here are some pics of my babies. I’m still looking for front rims for the 410 so yesterday I put the 310 wheels on took it for a drive. Working pretty good but still needs some carb work. Gotta get the 310 running next. Have a great day!😁

      · 1 reply
  • Adverts