Diff Idea

[CartsXJ]

I was thinking and this is a place to do it outloud so here it goes. I am going to be a senoir at wentworth int. of tech this spring and I need to do a senior project. I was thinking of designing and fabricating a selectable open-l/s-locker differential. I am just kinda feeling the waters and see what you guys/gals think. I was thinking something that would be open normal, pull a level or switch and it become a l/s, then hit is again and it would lock up. Was looking at a gear driven l/s, does anybody know where I can find an exploded view of a truetrac? I have a feeling that it would one of those "how do you fit all that stuff in such a little space?" questions. What diff should I be designing the prototype for? Should it be air/cable/electric operated? Just looking for some ideas, commits, questions, anything. Thank in advance.

Bill

[What Rd]

Sounds like a pretty ambitious project.
The type of diff I'd like to see (but don't think exists yet) is one that goes from open to an auto locker (like a Detroit that you can switch to run open). That might be a more achievable goal than what you describe, too.
Just a thought.
I've seen an exploded view of a Truetrac, but don't recall where it was. I think a good unit to design around would be the D44 -it's got to be one of the most common units and is used in both fronts and rears.
Good luck.

[dmillion]

You know what I'd really like to see, even more than better choices in differentials? A better transfer case.

To me a transfer case ought to have one lever that selects front-wheel drive, rear-wheel drive, or four-wheel drive, and another lever to select low-range, neutral, or high-range. Then I should be able to select any combination--front-wheel-drive high or low range, rear-wheel-drive high or low range, and four-wheel-drive high or low range.

Doesn't seem to me like it should be all that difficult to make them work that way. I would definitely be willing to pay a few extra bucks for a transfer case that worked like that!

[ChuckD]

Doesn't an Altas do what your talking about. There around $2100 for the 4.3 version.

[BrettM]

if you make a selectable locker, make it for the 14 bolt. they have a 10.5" ring gear, so that gives you some room to work in, and there is no selectable locker available for them and many people would seriously want one.

[Drewlee77]

The Atlas has two levers. Each lever controls one axle, and each level has three settings - High, Neutral, Low. Therefore you can have any combination you want.

[Drewlee77]

Perhaps think about this, I believe if this were built it would be the "ultimate" locker...

Forget the mechanicals for a moment and just imagine... Imagine a locker that allowed no slip ever. That is, when you are turning it forces the outside wheel to travel exactly the amount faster it needs to travel to not slip and it forces the inside tire to travel exactly the amount slower it needs to travel to not slip.

This would not negatively affect street driving - would not require any manual input from the driver - and would increase traction in all circumstances - even driving on wet/icy roads. It would not increase strain on the drivetrain like a regular locker and it would give you your full turn radias always... or maybe I'm just a hopeful fool.

Now the only way I can think of for this to work would be if it was a limited slip with variable bias - variable down to ZERO (or whatever you call fully-locked) This could be syncronized with the steering input through a hydraulic or gear-driven setup perhaps. Hydraulic would allow even a non-steering rear axle to work the same way(otherwise, I think it could only work on the front). I know that varible-LS exist (WJ Overland has them front and rear and they work pretty well). I'm sure there are realistic problems with the idea (e.g. you'd probably need a fully custom diff) but in theory wouldn't it work beautifully?

[CartsXJ]

Thinking on the 14bolt idea, does anybody no why there isn't a selectable locker for it. I was looking at this page earlier and already thought of a way to make a selectable for it: http://www.pirate4x4.com/tech/billavista/14b_bible/index.html

Did I miss something :anon: or am I brilliant :D and thinking outside the box? If not :wstupid:

[dmillion]

Actually, you can't have any combination you want with the Atlas transfer case. It does not allow you to put the front axle into high range and the rear axle into neutral at the same time, so no front-wheel drive in high. Why, I don't know. Can't see any good reason why it shouldn't be possible, but it is not possible with the Atlas setup.

[ChuckD]

Originally posted by dmillion
Actually, you can't have any combination you want with the Atlas transfer case. It does not allow you to put the front axle into high range and the rear axle into neutral at the same time, so no front-wheel drive in high. Why, I don't know. Can't see any good reason why it shouldn't be possible, but it is not possible with the Atlas setup.

Why?

Say if you are crawling home, because you busted your rear dirveshaft for example, wouldn't you just pull it off anyway. Then just put it in 4wd High and go.

[Drewlee77]

The Atlas does allow FWD Low though... and now that I think about it, it makes sense. The reducing gears must also be the gears that allow engagement of the front driveshaft. I don't know if I discribed that right, but it makes sense to me...

[bluexj89]

What i would like to see is a three speed transfer case. one with High, somewhat of a stock low, then ultra low. Most of the time around here 4:1-5:1 low is just too low. But for some of the obstcals being lower would really be nice.

[CartsXJ]

Ok, so everybody wants a custom transfercase? Actually, the idea of a three speed t-case sounds really cool, and I already have a few ideas on the how-to's but that seems like a lot of work and fabricating for one semester. The possibility is there, just the time factor gets in the way. So, know body has any info on the 14 bolt and why they don't have a selectable locker for it?

[dmillion]

"Say if you are crawling home, because you busted your rear dirveshaft for example, wouldn't you just pull it off anyway. Then just put it in 4wd High and go."

Yes, putting it in 4WD high works just fine. And you can effectively make your rig front-wheel drive by taking the rear shaft off and putting it into 4WD high. The Atlas will not allow you to run with the front in high range and the rear in neutral at the same time, though--it is locked out.

Why? I don't know. Makes no sense to me. That's why I'd like to see a transfer case that allowed this.

[ChuckD]

Originally posted by dmillion
"Say if you are crawling home, because you busted your rear dirveshaft for example, wouldn't you just pull it off anyway. Then just put it in 4wd High and go."

Yes, putting it in 4WD high works just fine. And you can effectively make your rig front-wheel drive by taking the rear shaft off and putting it into 4WD high. The Atlas will not allow you to run with the front in high range and the rear in neutral at the same time, though--it is locked out.

Why? I don't know. Makes no sense to me. That's why I'd like to see a transfer case that allowed this.

Why would you need this feature? I don't see what the extra ability would acomplish.:confused:

[Jes]

Originally posted by XJCHUCK72
Why would you need this feature? I don't see what the extra ability would acomplish.:confused:

Ya, what he said. There is no reason to ever need front wheel drive hi-range.

Jes

[MrShoeBoy]

Originally posted by XJCHUCK72
Why would you need this feature? I don't see what the extra ability would acomplish.:confused:

Theres a perfectly good explination for Front 2wd high!:D

This feature would be used for when you want to pose as a ricer and pull the ebrake to do a smokey burnout with the front tires and pretend like your FWD car goes fast:rolleyes:

Sorry I couldnt help myself;)

AARON

[h.curtis]

Originally posted by CartsXJ
I was thinking and this is a place to do it outloud so here it goes. I am going to be a senoir at wentworth int. of tech this spring and I need to do a senior project. I was thinking of designing and fabricating a selectable open-l/s-locker differential. I am just kinda feeling the waters and see what you guys/gals think. I was thinking something that would be open normal, pull a level or switch and it become a l/s, then hit is again and it would lock up. Was looking at a gear driven l/s, does anybody know where I can find an exploded view of a truetrac? I have a feeling that it would one of those "how do you fit all that stuff in such a little space?" questions. What diff should I be designing the prototype for? Should it be air/cable/electric operated? Just looking for some ideas, commits, questions, anything. Thank in advance.

Bill

Hopefully this thread will get back on track. I think it is a great idea. Not an easy one, but you should go for it. I always thought a cable would be best. The OX locker is out there, but I think the install is out of hand. Something simple to install and that works great would be nice. I say go for it. I'll be your first customer when you get it together. Even if you could just make one that is a locker and open with a lever that is easy to operate and install.

Curt

[xj92]

I think electric operated would be the best, but not an electric motor that moves a shift fork, use some kind of electromagnetic pieces that move when charged instead. Electric wires are easy to setup and route, are small, inexpensive, etc.

[MrShoeBoy]

Originally posted by xj92
I think electric operated would be the best, but not an electric motor that moves a shift fork, use some kind of electromagnetic pieces that move when charged instead. Electric wires are easy to setup and route, are small, inexpensive, etc.


That would be a really cool idea but how well do magnets work under heat? Then how big would the magnet have to be in order to lock the diff?

AARON

[Amund2]

Klune-V underdrive and similar stuff gives you high, low, super-low and something in-between. But enough about transfer cases.

The ultimate diff I agree would be a selectable between a normal open differential and a Detroit-like locker. Fully locked just isn't as good as the Detroit way, because the wheels resist turning. I have a Powertrax No-Slip myself, and it's totally great. Actually, it's almost so good that I don't know if I'd need to ever "unlock" it.. :) But sometimes the one-wheel drive in turns is a little annoying, the judder when going off the throttle, and the extra driveline slop is not nice...