Do Lawn Mower axles have differentials?

[rtimgray]

This may be a silly question, but I'm completely unfamiliar with riding lawn mowers. Here's my question, and why I'm wondering.

Do riding lawn mowers (particularly low cost brands like a Wal-Mart Murray or similar) have a drive axle that has a differential (of some kind). Or are they effectively 1-wheel drive? Do they have a chain or belt driving the axle? Any help on this subject would be greatly appreciated.

Now here's why I want to know. My 8 year old boy and I are working on a project. We started out building a ride-tank for him to drive around the farm, but he has developed an interest in half-tracks (we watch a lot of WWII documentaries, play Axis & Allies wargames, etc). I'm wondering if I took off the tires on the back of a riding mower and installed a set of tracks, would the machine be able to turn.

I've tried to do some research on snowmobiles (thought that would be kind of similar) and it appears that at least some types of snowbiles have some kind of differential, but they aren't intended to be able to turn on a hard, solid surface.

Anyway, like I said, if anyone has any idea if this would work, I'd appreciate the help. I don't have a lawn mower, so I expect we will have to find a cheap used one to start with.

Thanks again. Take care.

 

[Tig]

My old Bolens rider has a differential. I believe it was made by Peerless. On my Murray the differential function is more or less built into the transmission.
My snowmobile does not have a differential.
I would think that the tracks would have to have a V shaped profile in order to be reasonably responsive to the front wheels choosing direction on a solid surface. When things get real soft you would need to brake the tracks independently to force the turn.
Sounds like a fun project. I hope we get to see pictures.

 

[Jimbrown]

I would think that one of the cheap made in China golf carts or UTV's that are showing up all over would make a better chassis. About the same price as the cheap mowers.

 

[KentT]

The better quality ones do, but the cheap ones may essentially just be one-wheel drive. Neither are designed for one wheel to sit stationary and the other turn -- only to let one turn faster than the other.

IMO, your best bet would be two hydraulically driven motors -- then one could actually turn backwards while the other turns forwards, similar to a real tank, dozer, skidsteer, etc.

 

[rtimgray]

The better quality ones do, but the cheap ones may essentially just be one-wheel drive. Neither are designed for one wheel to sit stationary and the other turn -- only to let one turn faster than the other.

IMO, your best bet would be two hydraulically driven motors -- then one could actually turn backwards while the other turns forwards, similar to a real tank, dozer, skidsteer, etc.

The design for the tank actually uses to electric motors to drive the tracks independently; that way, it can operate exactly how you describe.

The half-track is a different animal because we want to be able to steer it with a steering wheel as opposed to having to use two different motors. From the research that I've done so far on what I can find on (real) half-tracks, many of them drove/drive just like a truck, with no steering input required beyond turning the wheel. There are at least a few examples, thought, that could have the steering assisted by applying brakes to each side.

So I'm wondering if a one-wheel drive set-up from a cheap mower would work. I appreciate all of the suggestions so far. A key component to this concept is the "cheap" factor. This is going to be a spare time tinkering project with as little capital outlay as possible. The idea behind using a cheap mower as a platform is because they can generally be found (in some kind of running condition) for $200 to $500, depending on how nice you gotta have 'em.

Thanks again for the help and suggestions so far.

 

[kenmac]

don't know about the high end ones . But the murry's & some others have several small gears with a chain inside. They aren't that difficult to take apart. I've had mine apart to apply new grease to the gears

 

[Stimw]

Everyone I have ever seen has a differential. The problem is they won't be strong enough to handle what you want to do. For normal use they work when one wheel slips on mud or wet grass but to steer or piviot would over stress them.
I drove a D-9 dozer in the ARMY for two weeks and it was set up with two levers R & L and R & L brake peddles. The levers disengaged that sides drive. You pull one lever and the Dozer made a slow turn. If you pulled the lever and hit the brake it would piviot hard.
I also had a VW Dune Buggie with steering brakes on it connected to the rear wheels. If you pulled the R or L Handle the Buggie would make a very hard turn in that direction.
Both these vehicles had heavy enough spider gears to handle this.

 

[Lickity Split]

I have a Murray and would like to know if you can make it in to a possi lock ( weld the gears ).
I want to use it for hauling wood out of the woods, and will need the extra traction.

Thanks Lickity Split

 

[Ryan03]

Yes, most lawn mowers do have diffrentials. Most Murray, Craftsman, Yardman, etc. use a peerless transaxle. two of the Spider Gears as well as the spider gear pin are located inside a hollow ring gear, which is about 4 inches in diameter, with straight cut teeth on the very top edge, similar to many conventional gears. The spider gear pin slips into a 1/2 inch notch cut into the inside of the gear, while the other 2 attach to the axle shafts with a c clip. The ring gear has a lip machined onto the edge of it on both sides, all the way around. This lip fits into the top and bottom half of the gear case, and this is what supports the ring gear. I have been inside many of these during my lawn mower demo derby days. The thing they don't respond well to is trying to speed them up by changing the pulleys. I would install a grease fitting in mine and pump it full of high temp grease, but it was still just a matter of time before it blew up. Also, disassemble the trans and weld the 2 spider gears on each axle to there respective axle. The snapring groove on the axle is a weak link, and this is always where they break. Clearencing the case and welding the gear on helps to prevent this. WorkmensMower video by bjdewey01 - Photobucket CM5 video by bjdewey01 - Photobucket mower on fire video by Tater1977 - Photobucket Carrol County mower demo clip video by Tater1977 - Photobucket

 

[Tig]

I have a Murray and would like to know if you can make it in to a possi lock ( weld the gears ).
I want to use it for hauling wood out of the woods, and will need the extra traction.

Thanks Lickity Split

My Bolens has been "repaired" and now has a sold rear axle. It steers like a toboggan and front tires do not last very long because the side walls tear up. Cutting the grass was like crop dusting, long arcing turns to swoop back and get those last patches.
The Bolens would not be fun to maneuver around trees in the woods.