When my B21 is in 4wd should either axle lock? I wonder if it ever did, it doesn't now.
is 4x4 workig right? B21
- Thread starter Roundgunner
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What do you mean by either axle “lock”? Rear axle would always be engaged but both rear tires wouldn’t spin at the same time without the diff lock engaged.Front would be the same except no diff lock on the front. Are you looking for all 4 tires to be spinning the same if it’s stuck?
That’s what I was getting at. Was wondering if he is looking for all four tires to spin at the same time in 4wd. I do realize it has open differentials in the front and rear.
Compacts do not offer front locking differentials, but many larger Ag tractors now include this feature.
If he is, something is a miss. In reality, 4 wheel drive is actually 2 wheel drive unless the differentials are limited slip (clutch packs internally) or have mechanical differential locks.
People buy 4wd vehicles and think they are when in reality they are 2 wheel drive (one wheel front and one wheel rear).
To answer the comment about not ever having seen a Kubota with a front differential lock, both of my M's have rear differential locks and front differential locks. I can activate both and have true constant 4 wheel drive but no steering. For straight line only. Don't think I've ever engaged the front lock. Never had a need to. Rear, yes, front, no. Both are engaged with separate pedals in the cab mounted on the floor by the seat. Front is actuated via a cable, rear is linkage.
People buy 4wd vehicles and think they are when in reality they are 2 wheel drive (one wheel front and one wheel rear).
To answer the comment about not ever having seen a Kubota with a front differential lock, both of my M's have rear differential locks and front differential locks. I can activate both and have true constant 4 wheel drive but no steering. For straight line only. Don't think I've ever engaged the front lock. Never had a need to. Rear, yes, front, no. Both are engaged with separate pedals in the cab mounted on the floor by the seat. Front is actuated via a cable, rear is linkage.
Jchonline
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So for the OP if you engage 4WD at least 1 wheel on the front should be spinning. If it isnt then your 4WD is not working.
Thanks, Front spins. I have a steep asphalt driveway and run chains in winter. I just wondered if front was limited. I have never had it back to the dealer, always try to do my own maintenance. This has just been oils and filters. I did wear out the front tires. 1100 hours. The last couple years it has been used more as a skidder than a tractor.
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Jchonline
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Thanks for sharing the pictures. These little B TLBs are just amazing for their size. I almost bought a B26, but decided on moving up a few sizes for my acreage.
Nope, it really is 4x4. Power "has the opportunity" to flow to all four wheels. It's not like it defaults to one particular wheel in the front and one particular wheel in the rear.
Power always flows to the path of least resistance through an open differential. That means if all your tires are sitting on approximately equal tractive surfaces, power will actually be sent equally out. The minute one wheel gets on snow or ice or sand or whatever surface has less traction...then, at that point all the power will flow to that wheel. Using part-time 4x4 like on a pickup or tractor, power is forced to the front and rear axles, but from there it will go to whichever side is easier to turn unless they are both about equal.
No. In an open differential without a limited slip clutch pack, power delivery tends to go to the wheel that is slipping the least.
Why lockers are built and why limited slip is a factory option.
In my case I run an ARB Air Locker in my front diff and a Detroit Tru-Track in the back on my pickup truck.
That's not correct. Power will always flow through the path of least resistance. So in an open differential scenario, power will tend to go to the wheel that is slipping the most.
And THAT is why lockers and limited slips are made...to help move power to the side that is slipping the least (or in other words, has the most traction).
I know we're digressing away from the OP's issue, but I love this topic. I've spent years driving off-road in my vehicles. I had a built-up 1992 Range Rover for many years. I also have a 2018 Ford Raptor...and recently traded my 2017 F-250 diesel for a RAM 3500 diesel (manual trans). One of the cool things about the RAM is that the rear axle has the "anti-spin" differential which is essentially a geared Torsen rather than the usual clutch packs which wear out. Very similar to what the Raptor has on it's front diff.
??? If power went to the wheel slipping the least, you wouldn't need lockers. It ALWAYS goes to the path of LEAST resistance.
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85Hokie
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This has been discussed on several occasions.......
a tractor.....B series, BX series can only have 2 wheel drive .....yes 2 wheel, even when in 4wd !!!!!! How many times have you been on a slight incline where one rear is slightly off the ground and the opposite front is off the ground?????
THE free tires are spinning at a rate that is twice the rate if you were going in a straight line! SO .......
now you say - I am going to lock the rear diffy ............BOTH rears will spin at the same time and the same rate!!! That little ol front tire is still spinning at a larger rate than normal ,UNTIL the traction is regained on the front end, thus both fronts will pull.
so the absolute best a tractor (B -BX) can ever have is three wheel drive!!!!
Now some bigger machines DO have diffy lock on the front end and the rear....that will result in 4 wheeeeeellllss going the more or less same ratio and rate. I have never used a tractor with diffy lock on the front.
On a car ......2wd on ice one tire.....that tire spins - due to the least resistance - or the least amount of friction - and ....it spins twice as fast as normal!
In the old days - you were told to apply the brakes a wee bit to stop that from spinning a hopefully the easy spinning tire will slow down and the tire that has friction to the ground will get some of the rate of spin.
Now before people chime in on clutch packs and computer controlled rear ends......
we are talking about the tractors .......B - BX and maybe the L's and M's......
remember we are NOT talking about linear track subarus!
a tractor.....B series, BX series can only have 2 wheel drive .....yes 2 wheel, even when in 4wd !!!!!! How many times have you been on a slight incline where one rear is slightly off the ground and the opposite front is off the ground?????
THE free tires are spinning at a rate that is twice the rate if you were going in a straight line! SO .......
now you say - I am going to lock the rear diffy ............BOTH rears will spin at the same time and the same rate!!! That little ol front tire is still spinning at a larger rate than normal ,UNTIL the traction is regained on the front end, thus both fronts will pull.
so the absolute best a tractor (B -BX) can ever have is three wheel drive!!!!
Now some bigger machines DO have diffy lock on the front end and the rear....that will result in 4 wheeeeeellllss going the more or less same ratio and rate. I have never used a tractor with diffy lock on the front.
On a car ......2wd on ice one tire.....that tire spins - due to the least resistance - or the least amount of friction - and ....it spins twice as fast as normal!
In the old days - you were told to apply the brakes a wee bit to stop that from spinning a hopefully the easy spinning tire will slow down and the tire that has friction to the ground will get some of the rate of spin.
Now before people chime in on clutch packs and computer controlled rear ends......
we are talking about the tractors .......B - BX and maybe the L's and M's......
remember we are NOT talking about linear track subarus!
They really do have 4-wheel drive. If you lifted a tractor so all 4 wheels were off the ground, engaged 4x4, and put the tractor into gear (or pressed the forward HST pedal)...all four wheels would be spinning. The action of the differential is what causes loss of traction when on surfaces of unequal grip.
This has been discussed on several occasions.......
a tractor.....B series, BX series can only have 2 wheel drive .....yes 2 wheel, even when in 4wd !!!!!! How many times have you been on a slight incline where one rear is slightly off the ground and the opposite front is off the ground?????
THE free tires are spinning at a rate that is twice the rate if you were going in a straight line! SO .......
now you say - I am going to lock the rear diffy ............BOTH rears will spin at the same time and the same rate!!! That little ol front tire is still spinning at a larger rate than normal ,UNTIL the traction is regained on the front end, thus both fronts will pull.
so the absolute best a tractor (B -BX) can ever have is three wheel drive!!!!
Now some bigger machines DO have diffy lock on the front end and the rear....that will result in 4 wheeeeeellllss going the more or less same ratio and rate. I have never used a tractor with diffy lock on the front.
On a car ......2wd on ice one tire.....that tire spins - due to the least resistance - or the least amount of friction - and ....it spins twice as fast as normal!
In the old days - you were told to apply the brakes a wee bit to stop that from spinning a hopefully the easy spinning tire will slow down and the tire that has friction to the ground will get some of the rate of spin.
Now before people chime in on clutch packs and computer controlled rear ends......
we are talking about the tractors .......B - BX and maybe the L's and M's......
remember we are NOT talking about linear track subarus!
It has it's uses but steering isn't one of them. Strictly for a straight line pull situation. I've rarely used mine but it's there if the need arises. Usually, the rear lock is sufficient. Both of mine are M's. Far as OI know, all M series have front and rear mechanical lockers.
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No side that I can see. 4wd is 2wd without a locking differential. How it works.