Is it possible for a tractor to have limited slip?

[tulenutn2o]

Diff lock is the only thing I'm aware of on tractors, the independent brake pedals work too. As far as autos go, we would set the diffs up with tight clearances and achieve a poor mans posi, short of welding the spiders as in our dirt track cars. Some Ford vehicles have a neat feature in their autos where when it is in 2nd, that is indeed, what gear it is in. This allows reduced power to wheels and tends to control traction better. Sort of like that other power control device................your foot.

 

[Ford tractor]

I wish I had a link to a TV news story I saw last week where a Bimmer owner spun his tires fast and long enough on the ice to catch his car on fire.

I'm not sure where the exact ignition point was; but it was an interesting video.

I'm sure that was a fake video. Not possible to create enough friction to catch a car on fire from an ice burn out.

We called that a "dummy drop." We would put the car in reverse, then without stopping throw it in L1 (or whatever gear is on the other side of N) and floor it. It was more fun on country roads where a lot of tar had risen to the surface in patches. Man that was fun, but those poor cars took a beating.

"Dummy drop" is a good name. I have some splined shafts with all the splines missing from something similar Yes, I used to be much less intelligent!

 

[EE_Bota]

When doing those burn off's with one wheel near motionless, and one tire spinning, usually the speedometer indicated 120 MPH, as the speedo is driven by a gear in the transmission, so the driveline was going 120 and one tire was near motionless, then it follows that the spinning tire is going 240 MPH. It is a wonder that more of those old tires did not come apart.

James K0UA

Does that actually follow? I thought I understood how a diffy works, but now I am not so sure.

 

[Robb71]

Does that actually follow? I thought I understood how a diffy workes, but now I am not so sure.

No, even if only one tire is spinning the speed of the tire does not double.
The speed of the tire (one or both) is limited by the engine rpm and gear ratio. Theoretical top speed of the car is the same as the max speed the one tire will spin. Actual top speed of course is less due to friction, air resistance, etc.

 

[tulenutn2o]

No, even if only one tire is spinning the speed of the tire does not double.
The speed of the tire (one or both) is limited by the engine rpm and gear ratio. Theoretical top speed of the car is the same as the max speed the one tire will spin. Actual top speed of course is less due to friction, air resistance, etc.

Plantetary action comes into play.Check out this link for an explanation.YouTube - How spider gears work.

 

[EE_Bota]

No, even if only one tire is spinning the speed of the tire does not double.
The speed of the tire (one or both) is limited by the engine rpm and gear ratio. Theoretical top speed of the car is the same as the max speed the one tire will spin. Actual top speed of course is less due to friction, air resistance, etc.

Thanks. I could have tried to prove it to myself, but unfortutely, my Subaru Baja has limited slip, and a viscous coupling between front and back, and it will take any attempts at playing as a challenge to destroy the garage.

I asked some folks in the shop, and they said the free wheel will double. Then they said, they didn't know if it would double, but it will go right much faster.

 

[EE_Bota]

Plantetary action comes into play.Check out this link for an explanation.YouTube - How spider gears work.

Thanks! Most times when I know my tire is slipping, I have never been in a situation to SEE what that means. And even when on the tractor, I find I can't actually look (too risky) and even when I glance, it looks like a brown mud covered blur.
It is nice to learn something new, only for the price of asking!

This was also very good.
http://www.youtube.com/watch?v=K4JhruinbWc&feature=related

 

[tulenutn2o]

Thanks! Most times when I know my tire is slipping, I have never been in a situation to SEE what that means. And even when on the tractor, I find I can't actually look (too risky) and even when I glance, it looks like a brown mud covered blur.
It is nice to learn something new, only for the price of asking!

This was also very good.
YouTube - How Differential Gear works (BEST Tutorial)

I posted that link because I couldn't find the words to explain it, I must suffer from ALLTIMERS! I'm glad it helped. I saw that other one too, but the 4WD one was crystal clear-with no way to argue against.

 

[tcartwri]

I'll put my vote on post #5. The mention of planetary action and sun gears was made. Neither are in the common automotive axle.

You might want to look into that a little bit more.

 

[RickB]

You might want to look into that a little bit more.

K7LN is correct. Don't confuse a planetary unit with a differential. You might want to look into that a little more.

Some tractors have locking front and rear differentials. Some MFD tractors have limited slip front axles. I know of no tractors with limited slip rear axles, but am willing to be educated.