Are Open-Diff Chain-Drive Axles a Thing?

[l008com]

Is this a thing? I have a Manco Dingo so it's a simple solid axle with a giant gear on it.
As we all know, a solid axle with knobby tires will very quickly make a mess of any surface you're driving on. But with an open diff, I might be able to drive across the lawn once in a while without destroying it.

But what about when I'm off road? Well I never am but hypothetically, an open diff with a cable actuated lock machanism would be perfect. When I wanted to have more fun, I could stop, throw the lever and lock the axle. And when I wanted to have less fun, I could stop, throw the lever the other way and unlock the axle.

There are all sorts of mall powered vehicles out there, like ATVs and Gators and stuff. I'm sure many of them do have open or LSD or manual locking diffs. But most of them are also probably drive shaft driven, not chain driven.

So I'm pretty sure one problem a chain driven open diff would have is that the case/carrier would have to be held still for it to work, which is part of the job the drive shaft does in a car. But my kart has no rear suspension so it wouldn't be much of a problem to attach some kind of stabilizer bar from the case of the differential to the body of the kart.

 

[Denny]

You’ll still tear up the grass. That’s kind of what they do and how you drive them. By sliding the but around.

 

[madprofessor]

Even if the rear tires were greased-up slicks that could levitate across the grass, anything you do besides sit still and admire the nice yard will tear up the grass with the front tires alone. They have tread on them for a reason also, to bite into the turf to turn the kart.

 

[Kartorbust]

Few options exist, the Peerless 100 differential exists(ed) requires a sprocket with a unique bolt pattern. Getting an older Miata differential with or without the Torsen mechanical limited slip. Quaife is another option but its stupid expensive.

 

[Willie1]

Few options exist, the Peerless 100 differential exists(ed) requires a sprocket with a unique bolt pattern. Getting an older Miata differential with or without the Torsen mechanical limited slip. Quaife is another option but its stupid expensive.

The Peerless 100's still do exist - really not that hard to find new or used. I've bought 2 of them new in the last year for under $150 each shipped. They can be found with both 3/4" and 1" axles and in a variety of widths and wheel mounting machining.

I used to source them used from small rear engine riding mowers and commercial walk-behinds. Funny thing is someone copied the Peerless 100's and made their own versions. True Peerless units should have 16 tooth side and spider gears - the copies are 15 tooth.

 

[Willie1]

As to the yard damage issue.
Karts with solid axles only want to go straight - the front tires have to dig in and force a rear tire to slip, and this is what causes most of the damage. An open diff in the rear will be a lot more forgiving to both turning and not damaging the turf.
But don't expect either to be entirely scuff free.

 

[l008com]

I didn't get notifications from the 6th or 7th. And I only just came back to this thread because I was on craigslist and I found this crazy little goofy 3-wheeler thing form the 70s that has a differential. It's more or less just what I'm looking for, a chain driven diff. I also googled Pearless 100 and it looks like the same exact thing.

So an open diff would be an upgrade. But an open diff that I can manually lock out to increase the fun would be an even better upgrade. Doesn't look like there's any way to do that though. But it's a start!

 

[l008com]

Here's an intersting video talking about that diff if anyone else is searching and finds this thread:

 

[Willie1]

This is a Peerless copy-cat from a Homelite/Jacobson rear engine rider, and it has the drive sprocket mounted correctly on the diff. I say it is a knock-off because true Peerless 100's have 16 tooth internal diff gears, where these are 15 tooth. There is also a slight difference in these case halves than Peerless ones. In this case the side gear is staked on to the axle - the P 100'S axles are retained with snap rings.

 

[Willie1]

So I'm pretty sure one problem a chain driven open diff would have is that the case/carrier would have to be held still for it to work, which is part of the job the drive shaft does in a car. But my kart has no rear suspension so it wouldn't be much of a problem to attach some kind of stabilizer bar from the case of the differential to the body of the kart.

In your video above - it shows the sprocket attached to the axle, which effectively makes it only drive the one tire, and the diff and the other tire to rotate freely. It is pretty much a wasted and incorrect use of a diff axle. In that application - if you hold the diff case from rotating as you mention and use the chain to drive the axle forward, the other axle/wheel will rotate in the opposite direction at the same speed.

 

[l008com]

Hey says in the video that the right way to do it is to connect the gear to the center of the diff directly. Driving just one axle would still work for non-off-road, non-fun-based vehicles. Like an electric powered vehicle that moves around inside a smooth warehouse floor.

 

[Willie1]

The first pic I posted above shows the sprocket mounted to the diff "correctly". On the projects I use these axles on, I mount the drive sprocket to one side of the diff and a brake rotor to the other side, so it will drive both axles and brake both axles. Too much power still spins one tire, although not as easily as just driving one axle. And if you apply too much brake on loose surfaces - one tire can continue to roll forward, while the other one spins backward LOL.

And yes, as you mention - driving one axle will still move the vehicle and will permit easy turning. IMO that would be more of a "use what you have lying around situation" than engineering it that way from scratch and buying all new parts. There are easier and cheaper ways to just drive one tire.

Enjoy your project.

 

[l008com]

Looking more and more at this axle and thinking about it, I feel like you could design a locking mechanism fairly easily. Assume you have the main drive gear fixed to the diff body. Then if you could make two cup-shaped objects that could slide over the whole diff casing, and lock into the sides of the drive gear with some precision drilled holes. Some mechanism would let these cups slide in and out, locking and unlocking the diff. Only while stopped, not while in motion. Else they might go the way of a G80 locking diff in a V8 powered SUV
I don't think I have the fabrication skills to make something like this. Plus it would essentially be a second diff case to go around your diff case, so it would take up a lot of space. But first things first, the kart isn't even running right now If I ever do a reverse project, I'll see if I can do an open diff axle at the same time.

 

[Willie1]

If your goal is to have a rear axle that can be changed from single to two wheel drive there is a simple way to do it.
Take a page from 2 stage self-propelled snow blowers. They use a solid axle and wheels that are held on with lock collars and are driven with bolts through the wheel hubs and axles. At one end an easily removed hitch pin is used to drive the axle when wanted and pulled when not.

 

[TNThomas]

Im currently building a 6 wheel buggy with duel rear diffs. Its not too bad to make. Midwest Miata has one in stock for $50 right now. I found two for $25 per on there. Pricey shipping however. With the miata setep, you could manually switch to a solid axle if you were to unbolt the diff setup, and bolt in a solid axle/sprocket in its place. Not fast, but its possible:

.

I used low temp aluminum weld rods for my can lids.

 

[FlyFrog]

This is a Peerless copy-cat from a Homelite/Jacobson rear engine rider, and it has the drive sprocket mounted correctly on the diff. I say it is a knock-off because true Peerless 100's have 16 tooth internal diff gears, where these are 15 tooth. There is also a slight difference in these case halves than Peerless ones. In this case the side gear is staked on to the axle - the P 100'S axles are retained with snap rings.

i have a rear end very similar to that, it came stock on a bird baja cart from the 60s i think, i wish i had more info for you guys about it but it works really well except in mud on hills, it spins the tire with least resistance and you get stuck, but it handles better than my klipper cart with a solid axle that hates turning and when it turns it slides and drifts around, fun for drifting but not precise driving, the baja is good for precise trail riding

 

[Willie1]

OK - I drafted this up because I was bored . . . R E A L L Y bored . . .

It is "possible" to attach a torque limiting clutch on a jackshaft and have a limited slip differential axle.
POSSIBLE, not cheap or easy. They sell torque limiting clutches for machinery that are adjustable and
rebuildable. There are options for chain types and torque ratings, along with shaft size. The clutch body is
keyed to the shaft, and it drives it's sprocket by a clutch plate that is adjustable with the retaining nut.
The one I looked at in McMaster-Carr is adjustable from 25-60ft/lbs. Nice thing is that if the clutch fails
or a chain comes off you will still have drive through the axle diff.

Bad news? Starting with a new Peerless 100 ($150) and buying the clutch, sprockets, chain, bearings, shaft, etc.
from McMaster ($250-300) this would not be a cheap investment.

As I said - I was bored, and just wanted to show a way that someone - given a fat budget, fab skills, and some time
COULD end up with a limited slip axle. And this is just a quick draft of the fundamental of operation, so don't
nitpick the off scale aspect of the drawing.

 

[l008com]

Would a cheaper solution simply be this:
A peerless 100 open diff. Two rear brakes, one on each side. Two master cylinders that would both be activated at the same time by the brake lever. But a pair of other levers located on the little control panel somewhere that would let you hit the brakes individually. Then if you're stuck and one tire is spinning, hold it's brake and hit the gas and the other tire should move and get you right out. I would imagine you could set up a system like that pretty easily.

 

[Denny]

I don’t see why you could not build one from a pto torque limiter. Just need to make sure it is balanced real well for high speed.

 

[Willie1]

Would a cheaper solution simply be this:
A peerless 100 open diff. Two rear brakes, one on each side. Two master cylinders that would both be activated at the same time by the brake lever. But a pair of other levers located on the little control panel somewhere that would let you hit the brakes individually. Then if you're stuck and one tire is spinning, hold it's brake and hit the gas and the other tire should move and get you right out. I would imagine you could set up a system like that pretty easily.

Yeah, I had a 3 wheeled trike (Tri-Sport?) years ago that had a similar setup. It had a brake lever on each side of the handlebars that operated a drum brake on it's side of the trikes rear tire. It was fun to grab the inside lever for turns, but kinda hard to use in mud. You pretty much need to run disc brakes to do that with any effectiveness - it's hard to control the self-energizing effect of drum brakes wrap around band to control the slip of the drum to give resistance but not lock up the drum. Discs are much easier to modulate.

So, yeah - that is another option that is more cost effective that the one I suggested. Setting it up with one control to operate both brakes and another pair to run the brakes individually would be the tricky part. Easier to do that using cable operated discs than hydraulics. While as I suggested, the system I drew up is expensive and slightly complicated - it also is automatic system that you don't have to operate separate controls to make it work. But I've never seen anyone here suggest anything
like it so I just wanted to show a new idea.

Again - bored - drawing.
If I was going to use the brakes to work as you suggested - here's how I would do that. Use a foot pedal to control both brakes - you will need more pressure to apply both brakes than would be comfortable by hand. A cable or rod would pull in the center of a floating balance bar - this would apply both brakes. The front levers could be mounted as the builder chooses -
levers on the sides of the seat, on the wheel, etc. Applying either and it just applies that side brake - the balance bar needs to be able to slide up the apply rod or cables so it won't interfere with the other side. Obviously you are using mechanical brakes - hydraulics would be hard to make this work.

Again - just a proof of concept drawing - not to scale.