BX 4x4 drive system question .......

[Chugbug]

Question with the fronts off the gound and you spin them do you hear the gears clicking/ticking. This happens in or out of 4wd

 

[leonz]

In 4WD , if ANY wheel spins , the other 3 stop . If I apply the diff locker
( rears only ofcourse ) then the two rears will sync and it moves on.
Question ; Why does the other drive shaft stop being driven when
the first drive shaft starts to spin a "lost - traction - tire" ?

Which is referred to as a "Limited Slip Differential" otherwise you would be tearing out the front and rear differentials which is a very expensive proposition.


This is also why you can effortlessly turn your car or truck.

 

[CompactTractorFan]

I noticed the same thing on my BX25 when I got stuck in a hole...

 

[funwithahoe]

Thankyou all for your obervations :thumbsup:
I must have been spinning one on each axle

Yeah - The left front and right rear could spin but with no disrespect I highly doubt that only one wheel of the four spin.

You likely have one front and one rear spinnning and if you have a diff lock then two rear and one front spinning. Sometimes tractors are so slow you have to watch the wheels for a minute until you realize they are spinning and that is probably the case here. Keep in mind the slack out of the linckage has to be used up before they start to spin!

My new b3200 doesn;t have the same "click" that my old "L3750" had when the diff locked so I assumed it didn't work for a while and then finally I had a chance to see both the right and left spin at the same time and low and behold the diff did lock!

Good luck and welcome to the forum!!


Thanks!

 

[RoadHogg]

Yeah - The left front and right rear could spin but with no disrespect I highly doubt that only one wheel of the four spin.

Umm, you're right, :thumbsup: cause if neither rear wheel were spinning, you'd be moving and therefore neither front wheel would be spinning either.

 

[turkish]

I figured it worked as most of you say in 4wd: power sent equally to both front and back so that a front and a rear will spin when stuck. That would make one believe that the tractors have a "locking center differential," just as 4wd trucks have (different from AWD in some suvs that proportion power front to rear). BUT, I know that with trucks with a locking center diff (that sends equal rotation to both front and rear, same as these tractors) you can not have different size tires or different gear ratios, front to rear.

How can tractors, then, have such drastically different tire sizes, front and rear, if their 4wd system sends equal power to both ends.

I don't see how these tractors can really have 4wd (power sent equally front to rear) with different size tires at both ends.

 

[TripleR]

I figured it worked as most of you say in 4wd: power sent equally to both front and back so that a front and a rear will spin when stuck. That would make one believe that the tractors have a "locking center differential," just as 4wd trucks have (different from AWD in some suvs that proportion power front to rear). BUT, I know that with trucks with a locking center diff (that sends equal rotation to both front and rear, same as these tractors) you can not have different size tires or different gear ratios, front to rear.

How can tractors, then, have such drastically different tire sizes, front and rear, if their 4wd system sends equal power to both ends.

I don't see how these tractors can really have 4wd (power sent equally front to rear) with different size tires at both ends.

I am not a mechanic, but couldn't that be accomplished by using different ratios in the front and rear differentials?

 

[RoadHogg]

I figured it worked as most of you say in 4wd: power sent equally to both front and back so that a front and a rear will spin when stuck. That would make one believe that the tractors have a "locking center differential," just as 4wd trucks have (different from AWD in some suvs that proportion power front to rear). BUT, I know that with trucks with a locking center diff (that sends equal rotation to both front and rear, same as these tractors) you can not have different size tires or different gear ratios, front to rear.

How can tractors, then, have such drastically different tire sizes, front and rear, if their 4wd system sends equal power to both ends.

I don't see how these tractors can really have 4wd (power sent equally front to rear) with different size tires at both ends.

What you're calling a "center differential" is known as a "power divider". Yes, it does the same job front to back as a differential does side to side, just a different name to help keep them separate in our minds I guess. Not many 4WD vehicles have power dividers. They don' t have "locked power dividers" as you suggest, they simply aren't there. Front and rear drive line are both turned the same, all the time, when 4WD is selected. This is called "full time 4 wheel drive" as opposed to "All Wheel Drive". That's why you'll always get one front and one rear wheel spinning (or three wheels spinning) but never only one wheel spinning.

You can put whatever size wheels and tires on a 4WD vehicle you care to if you engineer the difference into the transfer case.

 

[funwithahoe]

What you're calling a "center differential" is known as a "power divider". Yes, it does the same job front to back as a differential does side to side, just a different name to help keep them separate in our minds I guess. Not many 4WD vehicles have power dividers. They don' t have "locked power dividers" as you suggest, they simply aren't there. Front and rear drive line are both turned the same, all the time, when 4WD is selected. This is called "full time 4 wheel drive" as opposed to "All Wheel Drive". That's why you'll always get one front and one rear wheel spinning (or three wheels spinning) but never only one wheel spinning.

You can put whatever size wheels and tires on a 4WD vehicle you care to if you engineer the difference into the transfer case.

I agree with this poster and boy do I wish there was an engineering society that would define all the terms used for 4WD!

The marketing teams sure do make it confusing and I understand all the confusion out there!

 

[turkish]

I am not a mechanic, but couldn't that be accomplished by using different ratios in the front and rear differentials?

Yes, it could, theoretically. By offering that solution, I can tell you understand what I was saying (afraid I wasn't explaining it well). I started to offer that caveat.

Although, not being a mechanic, I wonder if they could get *close enough* with a gear ratio correction not to cause binding. Surely someone knows the answer.