Looking for info on MAX running gear for a project

[Canadian_Zuk]

If it is a limited slip unit I would think turning radius is suffer greatly unless you come up with a way to uncouple the inside drive for turning. Hope for an open differential.

[mpilihp]

Ok thanks guys, so if I jack up one rear wheel and can spin it with the other side wheel stationary that means it is usable?

What is the difference with a limited slip vs an open differential and how can I tell the difference?

The idea will be to put a brake on each side that is independently controlled so I can intentionally stop/slow the inside track to assist in turning.

Thanks

~ Phil

[Canadian_Zuk]

Ok thanks guys, so if I jack up one rear wheel and can spin it with the other side wheel stationary that means it is usable?

What is the difference with a limited slip vs an open differential and how can I tell the difference?

The idea will be to put a brake on each side that is independently controlled so I can intentionally stop/slow the inside track to assist in turning.

Thanks

~ Phil

Best test is to jack up both sides and spin the input. When you turn the input both axles should rotate in the same dirrection, if you hold one of them stationary while you continue to spin the input the oppoiste side axle will start to turn the other dirrection if it has an open diff. If you are unable to hold the one side stationary while you spin the input then you have a limited slip.

An open differential will send power to the path of least resistance, if the resistance is equal then both sides get equal power. If one side becomes more difficult to turn (ie brakes applied) then the open differential will bias power to the opposite side with less resistance. Think of a 2wd vehicle in the mud or on ice, one tire will spin free with an open diff while the other tire with the traction remains stationary. The only way to get that stationary tire moving (and gain forward momentum) would be to slow down the free spinning tire via traction or application of brake on that side to force the stationary tire into rotation.

A limited slip differential will "try" to transmit equal power to both axles regardless regardless of traction, with a limited slip differential both tires will spin in the mud or on the ice. If you use a limited slip diff you will either burn up the clutch pack in the differential or eat your steering brakes up at an alarming rate. There will be lots of heat too.

[dirtdobber]

Ok thanks guys, so if I jack up one rear wheel and can spin it with the other side wheel stationary that means it is usable?

Make sure the vehicle is in neutral or it won't spin (also make sure the vehicle won't roll). If you can spin one wheel freely its an open differential. "Freely" is a tricky term, because you will have to spin hard enough to overcome the friction of a dragging brake and all the bearings and gears through the differential and into the transmission. If you can spin one wheel with great difficulty its a limited slip, probably with bad clutches. If you can't spin one wheel then it's 100% positive traction. I don't think you will find a full-time 100% positive traction automobile differential unless its been modified. Some are lockable, meaning the 100% positive traction can be turned on or off (electronically for some Toyota's, mechanically for some GM's).

What is the difference with a limited slip vs an open differential and how can I tell the difference?

You can tell the difference as I explain above. The difference lies in the spider gear setup. An open differential has free-spinning spider gears. If you jack up both rear wheels, put the vehicle in park, and spin one back wheel the other will counter rotate, and they will both be fairly easy to spin. This is an open differential. A limited slip has a mechanism (clutches) that provide significant resistance at the spider gears and ultimately delivers more power to the wheel with lesser traction. Search youtube and you can understand this a whole lot better than I can explain it.

[Canadian_Zuk]

I think you did a better job explaining it than I did dirtdobber

[dirtdobber]

I think you did a better job explaining it than I did dirtdobber

I wouldn't go that far.

[mpilihp]

Thanks guys, so the truck is 4WD so it probably is not an open diff and it sounds like using a limited slip and applying brake to one side will damage it. The truck is buried under 2 ft of snow right now so will have to wait till spring to actually test but Ill ask on the mini truck forum and see if someone knows.

Another though I had was to go with two smaller snowmobile engines, one each powering a track and use the existing snowmobile chain cases with reverse gear in it. It would be tricky to synchronize the throttles but I have seen a couple two engine two track sleds so it can be done. Benefit of this is simplicity, availability of the parts (I have snowmobile engines I could use on hand.) And if there was a way to have a coupler between the two track drives, I could If one engine died, couple the tracks together and be able to limp home, would not steer well but could at least get out of the woods.

My issue here is figuring out the gearing to adjust for now having 21 in wheels instead of a track. I would have to gear it down but by how much?

Thanks ~ Phil

[Canadian_Zuk]

I'd be willing to bet that it is most likely an open diff, they are the cheapest to build, most reliable and require the least amount of service....Ideal for a utility vehicle like the Sambar. I'd just want to make sure it is infact open before investing to heavily in the project.

[mpilihp]

Ok thanks, so I did some reading up on the different types of diffs and based on what both of you said and what the writeup said I wonder if it is what I want.

What I read about open diffs is they are not ideal for off road ie poor traction environments, as soon as one can slip that side gets all the power. So this will be used in snow and I don't want to have one track slip and it gain all the power, this could cause me to get stuck say on a hill. Ill be towing a snow grooming drag, very heavy load...

[ARGOJIM]

There are ASV's and Thikol's for sale all over, saw a ASV a while back for under 5000, 3200 sticks in my head.

You want the cheap way to do it? Yes I know, so get 2 old snow mobiles and make a frame work tying them together, place your cab on the frame work, using the tied together steering skis steer with your feet or using electric power steering from a side by side( perhaps your most expensive part), one throttle in each hand preferably boat style will control each track for variable speed light turns assisted by steering with skis, hand brake on each throttle handle will control hard turns. If you want 4 stroke do that.

Done. Perfect no, but done.

[Canadian_Zuk]

Ok thanks, so I did some reading up on the different types of diffs and based on what both of you said and what the writeup said I wonder if it is what I want.

What I read about open diffs is they are not ideal for off road ie poor traction environments, as soon as one can slip that side gets all the power. So this will be used in snow and I don't want to have one track slip and it gain all the power, this could cause me to get stuck say on a hill. Ill be towing a snow grooming drag, very heavy load...

All Argos (except those with the Admiral tansmission) have open differential transmissions. You are building a tracked vehicle not a 4x4 truck, I seriously doubt track slippage is going to be any real concern. IF you ever find yourself in a situation where track slippage does occur and is causing you greif you simply apply the brakes to the side that is slipping to force power back over to the side with traction. You can limit the slip using the steering brakes.

I honestly think an open diff is the way to go, you may give up a slight amount of ultimate capability but you will gain reliability using an open diff.

[mpilihp]

There are ASV's and Thikol's for sale all over, saw a ASV a while back for under 5000, 3200 sticks in my head.

You want the cheap way to do it? Yes I know, so get 2 old snow mobiles and make a frame work tying them together, place your cab on the frame work, using the tied together steering skis steer with your feet or using electric power steering from a side by side( perhaps your most expensive part), one throttle in each hand preferably boat style will control each track for variable speed light turns assisted by steering with skis, hand brake on each throttle handle will control hard turns. If you want 4 stroke do that.

Done. Perfect no, but done.

Hi Im looking to make a smaller version of a ASV truck. that will not fit on all our trails, too wide. Ive thought about the idea of using sleds but I rather like the idea of large balloon tires with tracks on them and being able to take the tracks off and use it in the summer.

Thanks ~ Phil

[mpilihp]

All Argos (except those with the Admiral tansmission) have open differential transmissions. You are building a tracked vehicle not a 4x4 truck, I seriously doubt track slippage is going to be any real concern. IF you ever find yourself in a situation where track slippage does occur and is causing you greif you simply apply the brakes to the side that is slipping to force power back over to the side with traction. You can limit the slip using the steering brakes.

I honestly think an open diff is the way to go, you may give up a slight amount of ultimate capability but you will gain reliability using an open diff.

Ok thanks for the feedback, I did learn that the Subaru Sambar truck has an open diff so it is a possibility. This summer Ill be seeing if the engine can be fixed and if so Ill try that, if not the engine has to go and figure out a way to do it with an all new running gear setup.

Thanks

~ Phil