4X4 downhill traction issue

[csr0831]

YEs...actually I DO miss that tight turning radius. I used to think that the gravely was really "awkward" working around all the trees, now it is my machine of choice when doing that (the BX being the other choice). The GR was hard to beat when it comes to getting in and out tight places. : )

 

[SPYDERLK]

Sure will be interesting to see if the new tires fix the problem in themselves.. maybe we will all learn something.

They will fix the problem. Those turfs are almost like slicks on grass, esp if damp. He needs a sparser tread to link better with the ground.
larry

 

[jenkinsph]

Yes,it's a K664 and near as I can tell it's working properly.If it had no holding power on the downhill the tractor would immediately start sliding after launch.I've tried rear drive machines on this hill in the past.Tire type or weight makes little difference.I'm no whiz either,but I think the solution is to keep the front tires from losing traction.So,We'll see.



A pic of the backside of the front drive.I notice there is a short link above the tie rod that moves a shaft inside.While in the air I can turn one wheel with no affect on the other,doesn't try to turn backwards like a normal open carrier.Can also grab both wheels and turn them forward,meaning loss of engine power and the front axle goes along for the ride.

I would block up the rear wheels and see if you can rotate the front wheels faster than the rears while they are turning forward slowly. That would answer alot of questions. I wouldn't make any assumptions rather I would verify this.

Just speculating that the lever in your picture controls the wheel speeds in turns similar to the k92, making the outside wheel in a turn go faster and the inside wheel slower.

 

[locknut]

I would block up the rear wheels and see if you can rotate the front wheels faster than the rears while they are turning forward slowly. That would answer alot of questions. I wouldn't make any assumptions rather I would verify this.

Just speculating that the lever in your picture controls the wheel speeds in turns similar to the k92, making the outside wheel in a turn go faster and the inside wheel slower.

Ok,jacked it up and tried it.The wheels can be turned faster than driven speed,lust as I thought.There must be some sort of over-running clutch in the hubs.You can hear a muffled clicking sound when you turn them manually.How's the front end work on your 749,is it one of those that have individual gear motors?

Here's a vid of the GR on the hill.You'll notice the hydro straining,and towards the end on the last run down is the part that's longest and steepest.Not much room to turn and nowhere for a runaway to go,except the briars, stumps and small trees.

 

[jenkinsph]

So, if your front wheels will free wheel then they won't provide braking when driving down a hill. Hopefully the new atv tires will help with the rear tires traction.


My x749 is on a jobsite for a couple of days, I will jack it up and see what it does. So far it has held on some very steep grades for me.

 

[jenkinsph]

Yes,it's a K664 and near as I can tell it's working properly.If it had no holding power on the downhill the tractor would immediately start sliding after launch.I've tried rear drive machines on this hill in the past.Tire type or weight makes little difference.I'm no whiz either,but I think the solution is to keep the front tires from losing traction.So,We'll see.

The rears may be holding but the fronts are not, that makes it react the same as a 2wd on a downwards slope.

 

[94BULLITT]

Ok,jacked it up and tried it.The wheels can be turned faster than driven speed,lust as I thought.There must be some sort of over-running clutch in the hubs.You can hear a muffled clicking sound when you turn them manually.How's the front end work on your 749,is it one of those that have individual gear motors?

Here's a vid of the GR on the hill.You'll notice the hydro straining,and towards the end on the last run down is the part that's longest and steepest.Not much room to turn and nowhere for a runaway to go,except the briars, stumps and small trees.

http://i498.photobucket.com/albums/rr342/locknut-1/MOV00014.mp4

I am not sure if I understand. If you turn a wheel on a hydro in gear it will click.

 

[locknut]

The rears may be holding but the fronts are not, that makes it react the same as a 2wd on a downwards slope.

Yep,I guess you'd call it a hydraulic driven front wheel assist to the rear wheels.Of course,on the downhill you backpeddle the hydro and that puts a braking action on the front wheels as the gearmotor goes into reverse mode.You'll notice in the video I backpeddle the hydro on the GR a little to keep from overspeeding.These small tractors apparently don't have much holding power in the hydro neutral position.

 

[jenkinsph]

I live in a mountain ski town (Ruidoso NM) and often have to deal with steep slopes. I can drive up or down the slopes at a low speed without using the brakes. Just back off the hydro pedals. It seems to maintain the speeds without much fluctuation, my older L130 couldn't make it up the hills muchless down the hills with any control. I try to be careful of the slopes I tackle though since it is so dry here it can be easy to slide at times.

 

[jenkinsph]

I am not sure if I understand. If you turn a wheel on a hydro in gear I will click.

What he means is when you turn the front wheels on his tractor in the forward direction faster he hears a light clicking sound. So the wheels can free wheel not providing the four wheel braking that you have with a mfwd.