M7040 limited slip front axle

[Dave M7040]

It has snowed and I am getting to use my new M7040 under slippery conditions. The literature says it has a limited slip front axle but at times one front wheel just spins with the tractor stationary as both back wheels are also slipping. Tractor has 15 hrs on it.

Can anyone advise what a normal limited slip should act like.

Dave M7040

 

[kuboman]

It has snowed and I am getting to use my new M7040 under slippery conditions. The literature says it has a limited slip front axle but at times one front wheel just spins with the tractor stationary as both back wheels are also slipping. Tractor has 15 hrs on it.

Can anyone advise what a normal limited slip should act like.

Dave M7040

Limited slip is just that, limited. It is not a lock up a clutch pack that will limit individual wheel spin but not completely.

 

[94BULLITT]

Under certain conditions a limited slip will not engage.

 

[gwdixon]

Next time that happens try turning the fronts rapidly back and forth as traction is lost. Seems to work.

It does take a little bit until the limited slip is convinced to engage.

 

[xring100]

Dave,
I've observed similar performance on my M8540 Its far better than an open diff (Unlimited Slip Differential) Usually if i get substantial wheel speed differences The LSD engages. If it engaged to easy it would totally destroy ground and your tires every time your turned sharp with 4wd engaged. I have dug 4 ruts 6-8" deep in pretty hard ground while trying to pull various objects free.

It has snowed and I am getting to use my new M7040 under slippery conditions. The literature says it has a limited slip front axle but at times one front wheel just spins with the tractor stationary as both back wheels are also slipping. Tractor has 15 hrs on it.

Can anyone advise what a normal limited slip should act like.

Dave M7040

 

[MHarryE]

Generally MFWD front axles are not designed to handle 100% torque through 1 wheel. Gear and bearing sizes get too large (and expensive). Consequently limited slip diffs are prevalent and that is what you are describing. There are some tractors that have full locking front diffs but all that I have seen have a manual hold to engage button intending to reduce the time a person will have it engaged thereby limiting load. The "Detroit Locker" is available although don't know of tractors using it up front because a true locking differential causes steering issues. Something like the "Truetrac" differential is used on fronts. It will limit torque to about 70% of total available. A Truetrac doesn't create the steering problems that a full locking differential can. The Torsen is another brand name limited slip that I believe was first developed for racing cars where a broken axle on a locking diff would often result in a horrendous crash. The Torsen would provide all of the traction of a locker but would cut all power to both drive wheels if one axle shaft broke.

 

[ovrszd]

My M9540 limit slip works very well. I rarely use the diff lock. But as described, it's not a locker, it's a "limit slip", so sometimes it can't handle the torque put against it and will slip. A lot more productive than an open front axle. All Kubotas smaller than the M7040 are open.

 

[samofsweden]

Hi, I just read this thread, and I have an M7040 from 2009, but I havnt notice any limited frontdiff "acting" when I got stuck.
Are all M7040 equiped with limited front diffs.
/Sam

 

[MessickFarmEqu]

Hi, I just read this thread, and I have an M7040 from 2009, but I havnt notice any limited frontdiff "acting" when I got stuck.
Are all M7040 equiped with limited front diffs.
/Sam

all but the SU or limited models.

 

[Sammy3700]

Are the L or Grand Ls available with front differential lock? Thanks