Four-wheel drive; Not all tires turning

[Jimbabwe]

Howdy,

I have a new L3901 manual transmission.

Two things:

When I engage four-wheel drive with the "heel" lever behind my right foot and then try to climb a hill, I get stuck. The rear wheels and only the right front wheel spin. The left front wheel does not spin nor does it seem to be trying to spin. What's up?

Secondly, when "in" four-wheel drive, sometimes the "heel" lever just pops back to where it normally stays, out of four-wheel drive. Normal?

Thanks!
Jim

 

[hodge]

The lever at your heel is a differential lock, for the rear axle. It pops back up, when you take your foot off and the differential is no longer in tension. As far as the front axle goes, that is normal. You have a differential up front, also, which does exactly that- it differentiates. Unless traction is equal at both wheels, the one with lesser traction will spin. Under different circumstances, the opposite wheel may spin, and the right one not. The fact that one of the front wheels spins, proves that your 4WD is working. If it wasn't engaging, or there was an issue in the front axle, neither wheel would spin.
You will have a hand-operated lever to engage and disengage 4WD; the lever at your heel is only for the rear, and mechanically locks both rear wheels together. DO NOT engage it while the wheels are spinning- you will do damage.

 

[Creature Meadow]

Hodge nailed it, nothing for me to add here, nice explanation.

Jay

 

[Bmyers]

If you look at page 33 and 34 of your manual, as Hodge pointed out, the foot lever on the right side is the differential lock and on the left side, the handle is the front wheel drive engagement.

 

[Treckerzeug]

Hello,

Some tractors have no spin front wheel differentials or limited / partially locking front wheel differentials,
Italian tractors, or italian front axles mostly have these systems,
Japanese donot

 

[North Idaho Wolfman]

Hello,

Some tractors have no spin front wheel differentials or limited / partially locking front wheel differentials,
Italian tractors, or italian front axles mostly have these systems,
Japanese donot

Not true, Kubota has that option on the Larger tractors.

 

[Tx Jim]

I agree with NIW. It's my understanding that my '11 M7040 has limited-slip front differential but I rarely engage the 4WD.

 

[fruitcakesa]

What other models have the front axle LSD?

 

[troverman]

A rear differential lock has more value than a front diff lock. It's a rare situation where you can be stuck with power to three of the four wheels, and be able to power the 4th would get you out of the jam.

 

[Jimbabwe]

Thanks to all of you.

I guess I'm in a rare situation. It's often that the two rear wheels and the right front are spinning and I'm going nowhere...

Jim

 

[BigG]

Thanks to all of you.

I guess I'm in a rare situation. It's often that the two rear wheels and the right front are spinning and I'm going nowhere...

Jim

What are you trying to do that this happens often? Perhaps with some details someone on here might be able to find a solution to help you out. Pictures might also help.

There are limits to what a tractor can do but just as often there are alternatives that will help you get the job done.

 

[SidecarFlip]

Not true, Kubota has that option on the Larger tractors.

Exactly. Not sure of the latest M series have a front locker but both my M9's do. 2 pedals right next to each other, one for the rear locker, one for the front locker. I rarely use the front one and only ocasionally use the rear one.

The open differentials are just like a 4wd pickup, not really 4wd, in reality 2 wheel drive, one in the front, one in the rear (unless the truck has lockers).

 

[Dchemphill1]

As an L3901 owner (HST) I found the tractor to be pretty light weight...so had the rear ag tires filled and man does that make a difference. Do you have your tires filled? If not I would look into that to increase ground engagement.

 

[North Idaho Wolfman]

Thanks to all of you.

I guess I'm in a rare situation. It's often that the two rear wheels and the right front are spinning and I'm going nowhere...

Jim

Yea I wanna know what and how you making three wheels spin, I can only pull that off in the middle of winter!

 

[skeets]

Yea I wanna know what and how you making three wheels spin, I can only pull that off in the middle of winter!

I guess that would depend on how deep the mud was

 

[hope to float]

What pressure is in the tyres? (I run mine around 8psi)
Have you a loader with no ballast? (You could be taking enough weight off the back wheels even with an empty loader)
Have you the right tyres for the work you are doing? (Ag tyres are best for field work, grass tyres for lawns (& snow apparently) and industrial for road work and heavy loader work)
How steep is the hill?

 

[wwidmer]

Thanks to all of you.

I guess I'm in a rare situation. It's often that the two rear wheels and the right front are spinning and I'm going nowhere...

Jim

Not really, what was said was "...It's a rare situation where you can be stuck with power to three of the four wheels, and be able to power the 4th would get you out of the jam."

So very likely when you are stuck with 3 wheels spinning, if that 4th wheel were forced to grab with limited or no slip, very likely you just would still be stuck and it would also just spin along with the other 3. Have gotten stuck in mud myself on several occasions and had to either crab myself out with my backhoe or lift and place boards/logs under the wheels to get free. Mud can really clog those ag tires and turn them into slicks in no time.

 

[mdhughes]

I have a L3901DT and have been in mud up to the front axle and haven't gotten stuck yet, I have AG tires. It was really wet around here this last winter.

 

[Jimbabwe]

Brand-new heavy-lug tires, steep hills, loose dirt.

Since it doesn't lock all four wheels like my Yamaha Rhino, it's just not going to be as capable.

There are limits to the steepness of hills this machine will climb. Period.

 

[mdhughes]

Brand-new heavy-lug tires, steep hills, loose dirt.

R1's or R4's?