If you own an M35 you need this!

[hot rod deuce]

well as long as you didnt go and cut the back axle off you need this!

What I have is pile of parts that will make your life much easier and cheaper. We are all familiar with the horrable axle bind that comes from driving any M-44 seires truck down the pavement. Some people remove the rear drive shaft, but this not only takes time and is a pain but when you want 6 wheel peal but you gotta crawl under and put it back on. Dont forget getting the flanges lined back up. I usualy wind up jacking up one wheel to get it right.

The plan here is to replace your stock axle with an Alloy double splined shaft. This will let you to put a lock out hub on said axle. (the same hub that goes on a front axle.) This will allow you to "unlock" one axle.

Thus it will no longer power but you will not be binding up either. Saving both tire wear and gas milage. Not to mention a shorter turning radius that you can not put a price on. Now the big advantage of this is that when you want all wheel drive again all you do is go turn the dial to "lock".

PM for prices with a memebrs only discount.

 

[jwaller]

awesome idea. it's a bout time. pm me a price please!!!

 

[JEEPGUY]

SWEET IDEA MAN. DO YOU HAVE IT IN YOURS ?

 

[rmgill]

Squirt truck brought up a possible problem. What's the rear diff doing when you do this?

 

[gringeltaube]

from 6x6 to 6x2

What kind of problem? I would install that FW-hub on the middle axle and leave the rear axle as is. While moving forward, the rear axle gives better traction (gets a bit more load). Any speed difference between both axles while cornering will be absorbed by that free spinning shaft/hub, if unlocked. As long as the locking hub mechanism is strong enough I don't see any problems.
But if we wanted to save fuel, tires and significally reduce the turning radius when running unloaded we need to somehow (quick)disconnect the rear propeller shaft AND lift the rear axle up, via air bags or hydraulically, like the big rigs do. Who will be the first?

Gerhard

 

[rmgill]

RE: from 6x6 to 6x2

The problem that Squirttruck outlined was that the differential spider gears will be screaming as you run down the road.

 

[cranetruck]

RE: from 6x6 to 6x2

With any kind of cargo, the two axles are needed, lifting one is fine when empty....Would be nice to have a differential between the two tandem axles, hard to believe that one wasn't built.

HRD, good product, saves some of us the trouble of doing it ourselves.

 

[gringeltaube]

Re: RE: from 6x6 to 6x2

The problem that Squirttruck outlined was that the differential spider gears will be screaming as you run down the road.

Not at all. Running down a straight road there is little to no movement between the differential gears of both rear axles, with one unlocked or not. The diffs. would only compensate for some difference in tire diameter.
Of course that changes if the only drive axle starts loosing traction i.e. on gravel or wet surface. Than it's time to stop and dial in...

 

[rmgill]

RE: Re: RE: from 6x6 to 6x2

The differential is going to have zero resistance on one side and some amount of resistance on the other, drive input on that pumpkin is going to make that differential set spin one side more than the other because even just based on mass and not rolling resistance you're spinning either just a shaft on one side and a shaft, wheel, brake drum and tire on the other. Basically the unlocked side will spin a lot and the locked side will just spin as much as speed makes it turn.

 

[rizzo]

Re: RE: Re: RE: from 6x6 to 6x2

The differential is going to have zero resistance on one side and some amount of resistance on the other, drive input on that pumpkin is going to make that differential set spin one side more than the other because even just based on mass and not rolling resistance you're spinning either just a shaft on one side and a shaft, wheel, brake drum and tire on the other. Basically the unlocked side will spin a lot and the locked side will just spin as much as speed makes it turn.

right, but when you are going down the road they are all going to be going the same speed. the one connected wheel will be spinning as fast as the other wheels on the drive axle. both carriers are going to be going the same speed too. the spiders in the tag axle will be going as fast as the ones in the drive axle. if you lost traction on one wheel on the drive axle the spiders on the drive and tag will STILL be going the same speed.

 

[rdixiemiller]

RE: Re: RE: Re: RE: from 6x6 to 6x2

You will not have any issues running one unlocked rear wheel. You actually could have more issues if you unlocked both sides of a rear diff. If one axle has a tad more resistance to free rotation, it will stop turning. Then your spider gears would be screaming as the other side turned at 2X normal speed.
When driving down the road with one rear wheel unlocked, you will have a small amount of differential motion between the rear wheel hub and the unlocked axle. When turning, there will be a little more motion, but not enough to cause any problems.
As soon as I sell some of the scrap in the back yard, I intend to buy a rear axle kit and a pair of front hubs.

 

[Recovry4x4]

RE: Re: RE: Re: RE: from 6x6 to 6x2

I'm glad you guys figured that out! I went round and round over this very subject about 4 or 5 years ago with a bunch of folks on the Mil-Veh list. Some were very obtuse about the whole concept. I spent a long time on the phone with Art Bloom on this very subject. He's offered the kits in the past and one of our members has a kit on his water purification truck. On several trips I've removed a rear axle to conserve the juice. Anything more than one hub and a double splined axle is overkill. As explained, no problems wih the spiders, both carriers will be spinning the same speed so the only spidergear movement will come from different tire curcumferences. I offer this piece of advise though, NDTs, wet pavement and one rear drive axle on a deuce gets you stuck on blacktop real quick. Idealy, one should add a Detroit to the axle thats keeping both of the fixed shafts.

 

[readyman]

HRD,

Give up on the disengager HRD?
Today I just resplined the shaft to get rid of the wider index spline($75). This way it'll engage within a few degrees instead of a full turn.
Here is the basic concept using a couple of the original interaxle. With a full 3 inch spline engagement on both ends.

Looks like I'll need to shorten the interaxle drive shaft 3 inches after welding the splined shaft to the yoke where the splined hub was.

 

[M543A2]

Interaxle Shaft Modification

Readyman:
I'm not sure I understand your concept. How do you keep the shafts from separating when in the unlocked position? If they do, major problem! Or, do you intend to remove the shafts, and use the slider as an easier means of alignment when putting the shaft back in the truck?
The keyed spline is meant to keep the shaft yokes in time. If a driveshaft is not in time, serious vibrations can result when angular displacement occurs. The yoke half on each end of a shaft must align with each other for the joints to work without vibration during angular misalignment.
As for the discussions about the spiders when an axle shaft is removed, no abnormal motion will occur. The spiders are still controlled by the diff and the remaining connected axle. They will not turn in any abnormal way. I have removed one axle shaft from my trucks for years and many miles with no problems.
Regards Marti

 

[rmgill]

RE: Interaxle Shaft Modification

I think he has a yoke that'll keep them aligned but able to spin slightly differently as he makes corners.

 

[readyman]

RE: Interaxle Shaft Modification

It was just quick pic's to show the concept. Using existing parts.
I'll have a tube extension that'll keep the splined shafts aligned, same ID as the OD of the splined area.

I haven't mocked up the pneumatic actuator yet, that will engage/disengage the slider. Mounted on the diff.

M543A2,
Thanks. Wish I would have known the reason for the indexing spline before I started.
Think I'll have problems?

 

[Recovry4x4]

RE: Interaxle Shaft Modification

Its referred to as phasing. Driveline vibrations cancel themselvs out of the shaft is in phase and the pinion angles the same. Condidering the fixed geometry beween the 2 rear axles, I doubt that you would notice it.

 

[hot rod deuce]

RE: Interaxle Shaft Modification

Hey thanks for explaining this for me guys, i havent been able to get around here much lately just enough to send e mails.

Like ryan said the gears will take the difference, just like the inter axle on all other tandem trucks. The spider gears will be making up the difference any way so why not do it with out any load? I really dont think the RPM variation will be enough to do any thing.

Give up on the disconect? Me? Nope never will be here next week then all i got left to do is put the air cylinder on it.


pic's on this later

 

[readyman]

RE: Interaxle Shaft Modification

HRD,

 

[Rattlehead]

I bought a double splined axle and a Selectro hub from Arthur Bloom a couple of years ago, and it is great. I have it installed in the left rear-most axle. It makes a noticeable difference in turning radius and generally handles much better when driving around town, because you dont have the tandems trying to push you in a straight line during a turn. This also saves wear and tear on your front tires. Just wish the Oversion hubs were ought when I bought it! Anyone want to trade one for a Selectro? ha ha.