Locking the differentials on a D-Series. Fully Automatic?

[Spudgunner]

I was using the Search function on this site to explore the wonders of Work Mode and I came upon a thread that mentioned a couple of items that took me by surprise:
1. Lockup of differentials won't happen when All-Wheel-Steer is being used, and,
2. Somehow differentials can be locked with a switch or something.

I'm assuming that #2 is not for D-Series. This all is relevant to me as I managed to get stuck today to an extent that I had to call on a friend and his (t)rusty JD backhoe to pull me out. An observer noted that all power was being routed to one of my tires that had the least traction. This surprised me as I thought the TC had limited-slip. And yes, I was in AWS mode.

My conclusions were that #1 was TRUE for D-Series and, regarding #2, the D-Series has no switch/lever/whatever to manually lock out a differential. Are my conclusions correct?

Thanks!

Update: Further reading revealed that the limited slip is fully automatic. Given what I experienced today I still suspect #1 is true.

 

[trlbrkr]

With the D independant suspension we lost the locking differential on earlier models that had straight axles. Major loss that I hope will be solved on the E model. Of course the comfort in the cab is a great improvement over earlier models.

 

[radman1]

From a previous post, I recall someone saying one wheel could turn 2X faster than the other wheel but both would still spin. Maybe that doesn't apply to AWS mode. Will all 4 wheels spin in 2WS mode?

 

[Spudgunner]

From a previous post, I recall someone saying one wheel could turn 2X faster than the other wheel but both would still spin. Maybe that doesn't apply to AWS mode. Will all 4 wheels spin in 2WS mode?

My situation was that I dropped the two right wheels into a ditch next to the road I was plowing. I was in 2WS mode at the time. I could go forward and backward Ok but couldn't climb outta the ditch. So...just for fun..I switched over to AWS just to experiment a little. At that point my attention got diverted as a neighbor showed-up to see what was going on. After I talked with him a bit I jumped back in the cab to see what I could do. I could not move and all power, according to the neighbor/observer, was being routed to the front left tire (it was on the slick road surface). I didn't think to switch back to 2WS. About then Backhoe Man showed up and that resolved the problem.

Given these experiences I now operate under the assumption that I have open diffs when in AWS. I'm not 100% sure that's correct because when chained-up my toolcat will just about climb a tree...seemingly regardless of steering mode. But my experience in the ditch really would seem to indicate that AWS has no L-Slip.

D-Series does have Limited Slip according to the Bobcat website (as well as others). Apparently it doesn't do its thing in AWS, though....or at least not as well.(?)

Kevin

 

[theoshin]

My situation was that I dropped the two right wheels into a ditch next to the road I was plowing. I was in 2WS mode at the time. I could go forward and backward Ok but couldn't climb outta the ditch. So...just for fun..I switched over to AWS just to experiment a little. At that point my attention got diverted as a neighbor showed-up to see what was going on. After I talked with him a bit I jumped back in the cab to see what I could do. I could not move and all power, according to the neighbor/observer, was being routed to the front left tire (it was on the slick road surface). I didn't think to switch back to 2WS. About then Backhoe Man showed up and that resolved the problem.

Given these experiences I now operate under the assumption that I have open diffs when in AWS. I'm not 100% sure that's correct because when chained-up my toolcat will just about climb a tree...seemingly regardless of steering mode. But my experience in the ditch really would seem to indicate that AWS has no L-Slip.

D-Series does have Limited Slip according to the Bobcat website (as well as others). Apparently it doesn't do its thing in AWS, though....or at least not as well.(?)

Kevin

i understood it has limited slip but if the tire with the traction requires more pressure than the relief valve then you are stuck. so if it requires more pressure than the valve setting your tire will not turn even with limited slip. not sure if this is correct.

 

[radman1]

theoshin
You are correct. The relief valve may not let the wheel spin if there is too much traction. This helps prevent too much power to any one wheel and break an axle. This is what I was told by a Bobcat rep. However, in his situation, it would seem as though his traction was less than optimum given he could move but not climb out of the ditch. It seems strange that only one wheel would spin in his case of AWS. I challenge someone to tie their D toolcat to a tree and try pulling in 2WD and AWS to see what happens.

 

[dsb5610]

I could go forward and backward Ok but couldn't climb outta the ditch.

If it makes you feel any better I did the same thing with my 'A' only I was using the bucket. I wanted to push the snow away from the mailbox. It was very wet and the TC slid into the ditch (not steep). The wet snow was around 6" deep on the high side and over a foot on the low side. I tried locking the differential, crab steering, etc. Each time it would start up the incline then slide back down. Along comes a state plow truck. Guy pulls up right behind me and asks if I have a chain. I keep one in the back, threw it over the plow and I crab steered out. R4s work ok when traveling forward/backward but are horrible at holding sideways.

dsb