Antislip differential

[Gerg]

The traction control doesn't seem to work on my 7117. Any ideas?

[PhanDad]

See these posts:

https://simpletractors.com/forums/topic/32308-differential-question/?tab=comments#comment-32311

https://simpletractors.com/forums/topic/50115-7000-series-differential-question/

 

[TimJr]

Don't expect too much from the "limited slip/controlled traction diff".   It's just a little spring pre-load on the differential pinions/planet gears.  It just causes the need for a little extra break away force for lack of better description if you have one tire on a good surface and the other on a slippery surface.  If it was too "tight", it would tear up your lawn when you turned because it couldn't differentiate easily enough.

Don't mistake it for a locker/locking differential.  Just like in a car or truck, a limited slip/controlled traction diff just means there is a pre-load on the differential gears to help with traction on the side that wants to spin with no resistance. 

I have seen a Simplicity ad that I think was for a 90's Landlord.  It showed a tractor going up a ramp that was 4 or 5 feet long and probably 10 - 15 degree slope.  One was a normal ramp, the other wheel was on a ramp made of rollers like what you would see in a warehouse for moving boxes.  The tractor drove right up it.  I don't think any Simplicity I have ever been on would do that.  Maybe with enough momentum, but not from a standstill or slow speed.

[Gerg]

Thanks for the information, I may do nothing to the differential since I haven't added wheel weights or chains yet. my problem is when I was blowing snow one or the other wheel would spin even if I shifted my weight, never did both wheels spin at the same time.

Greg

[Gerg]

Anybody know why Simplicity dropped the old style differential with adjustable clutches and went to the spring loaded type? it seems like the adjustable would be great for winter use.

Greg

[Bill725]

The old style differential did not have adjustable clutches. The differential was open and there were 2 screws on the RH wheel hud which applied a force on the LH axle shaft. IMHO, the new style differential with the internal springs is the better of the two. In fact, I have already converted my 725 and will be converting my 2012 to the new style.

[Brettw]

If I recall correctly, the springs are still available and they are about 5-6 bux each.  Rebuilding the 8 gears then costs about 40-50 bux. New springs would tighten up the diff, and in the process clean everything up, new grease, etc.  Just a thought.

[Gerg]

Thanks for the information, I will take it apart in the spring when it is warm. I am going to get chains and weights for it before winter is over, may not need to tale it apart.

Greg

[MikeES]

Do you have the situation that one wheel is spinning and the tractor is. not moving?

I have had one tire spinning faster than the other,  but have never really experienced the tractor spinning one wheel .and not moving.  If I’m not moving, both wheels are spinning.

With our pulling tractors, I took out the springs in the diff,(no longer limited slip) and never once experienced a one wheel spin out like the cub cadets.  Always ended the pull with the front end off the ground and both wheels spinning in the dirt or blacktop.

 

[Gerg]

The tractor comes to a complete stop due to icy conditions (no movement). One or the other wheel (usually left wheel) starts to spin, the other stands still, even if I transfer my body weight to the side that is spinning. I have never seen both wheels spinning at the same time nor does it transfer back and forth between the two. It acts as if the limited slip isn't working at all.

Greg 

[Brettw]

On 11/30/2018 at 11:41 PM, MikeES said:

With our pulling tractors, I took out the springs in the diff,(no longer limited slip) and never once experienced a one wheel spin out like the cub cadets.  Always ended the pull with the front end off the ground and both wheels spinning in the dirt or blacktop.

That is likely a function of the spider gears being allowed to mesh with each other basically locking the axle. And that would mean some are, some aren't some partially locked, ,etc.  It doesn't sound to me like a good idea to simply remove the springs.  All that being said, locking the axle is great for pulling, but not so much for everyday use, cutting grass, etc.  Makes it a lot harder to steer the tractor and tears up turf, and in the snow they tend to "plow" (under steer)  enough already.  That's why the limited slip vs the differential being locked.  That's why the tractors with a diff lock are set up to turn it on and off as needed.  JMHO

[TimJr]

I think he put in a spacer in place of the springs.  Seems like that came up in a pulling discussion one time.  that way it was just a plain open diff, which can help make a pulling tractor more steerable via weight shifting.

[MikeES]

On ‎12‎/‎2‎/‎2018 at 7:34 AM, Brettw said:

That is likely a function of the spider gears being allowed to mesh with each other basically locking the axle. And that would mean some are, some aren't some partially locked, ,etc.  It doesn't sound to me like a good idea to simply remove the springs.  All that being said, locking the axle is great for pulling, but not so much for everyday use, cutting grass, etc.  Makes it a lot harder to steer the tractor and tears up turf, and in the snow they tend to "plow" (under steer)  enough already.  That's why the limited slip vs the differential being locked.  That's why the tractors with a diff lock are set up to turn it on and off as needed.  JMHO

TimJr post is right on!  Did notice a small change in "weight shift steering".

The diff is not locked, it is put together just like the older diffs with the spacer in place of the springs.  I had trouble with the springs compressing under load and then losing full contact on the spider gears and then BLAM you have a pile of useless parts.

A locked diff does not work at all for pulling.  If the officials don't DQ you for having a locked diff (dangerous) you will DQ yourself because you won't be able to keep the tractor straight on the track.

My point is that my experience with the Simplicity transaxle is pretty positive (pun intended).

Edited December 4, 2018 by MikeES

[Brettw]

37 minutes ago, MikeES said:

The diff is not locked, it is put together just like the older diffs with the spacer in place of the springs. 

Ahhh.  Now that makes sense.  

[Chris727]

I just had the diff apart on the B-210 over the weekend. It was locked and was very difficult to steer. It turned out someone had the axle gear flipped the wrong direction and they omitted the axle washers on the differential side. I used a donor diff and checked it over and cleaned it up. I'm getting great differential action now.