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ECO Hubs Who needs 3:07 gears?

GeneralDisorder

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Not to offend those who do/did...

Not in a MILLION years.

As ballast for a farm tractor to help keep the vehicle from tipping over, sure.

Beyond that, nope.

My reasons are based on fluid dynamics.

But if people "think" it helps, that's all that matters.

:)

*and if you do, dilute that shit good (it can be caustic)
Can you provide any links with information on the fluid dynamics that contra-indicate use of antifreeze (mixed with water) for balancing? I'm certainly interested to read about it given that my tires are full of the stuff already :unsure:

Anti-freeze contains corrosion inhibitors as well as zinc as a sacrificial anode. It's not just straight Ethelene Glycol. I'm pretty familiar with it's use and what it will and wont corrode generally. I'm not worried about my powder coated rims which are effectively plastic. And I'm of the opinion that it's not going to be an issue till long after I need new tires due to age anyway.

Ethelene Glycol should have zero effect on the inside surface of tires. The inner surface is Butyl Rubber due to it's very low permeability (holds air), and is 100% compatible with EG. I've posted videos before of reported anti-freeze used in tires for 10 years with seemingly zero effect on the Butyl.
 

Third From Texas

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Can you provide any links with information on the fluid dynamics that contra-indicate use of antifreeze (mixed with water) for balancing? I'm certainly interested to read about it given that my tires are full of the stuff already :unsure:

Anti-freeze contains corrosion inhibitors as well as zinc as a sacrificial anode. It's not just straight Ethelene Glycol. I'm pretty familiar with it's use and what it will and wont corrode generally. I'm not worried about my powder coated rims which are effectively plastic. And I'm of the opinion that it's not going to be an issue till long after I need new tires due to age anyway.

Ethelene Glycol should have zero effect on the inside surface of tires. The inner surface is Butyl Rubber due to it's very low permeability (holds air), and is 100% compatible with EG. I've posted videos before of reported anti-freeze used in tires for 10 years with seemingly zero effect on the Butyl.
I'll dig something up for ya on the fluid dynamic aspect.

As far as the corrosive nature, that dates back to when I had a radiator shop. The supplier we used for cores (Modine) warned about running straight antifreeze (opposed to diluted). The literature provided at the time broke down the various types, inhibitors used, and chemical reactions with metals/solder (I don't recall negative effects on rubber). But from what I recall, it was more far more of an issue the greater the exposure to oxygen increasing the corrosive issues (keeping in mind that a cooling system is flooded and tires wouldn't be). No doubt rims that have been powder coated on the inside would be far less susceptible to corrosion (but most LMTVs likely don't have that same level of protection.

I've read lots of pros-cons on using antifreeze (especially since I got my first A0 and lost a few fillings). We ran an Off Road Center here (4x4 lifts, etc) and we saw some nasty messes when some guys ran it trying to balance their big Mickey Swampers and such. I read a lot of LMTV user results (everything from "it all just disappeared" to "my CTIS systems acted really funny with antifreeze inside of it". I'm just not a fan and personally have no interest in messing with it. I merely suggest that anyone looking to pour antifreeze into their tires do some research first and understand all parameters in the instances where people say that it worked for them.

To each their own. IMO, beads would be far more efficient. But I thankfully I don't have any vibrations issues to cure.
 

chucky

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I have not put anything in the 395s yet but a few months back put some in brand new 15 in trailer tires to see first hand and when the tires got put on they were out of balance so i let the air out of them and jacked the trailer back up and sucked 12 oz back in each tire and so far so good they run smooth so now to look at long term effects when i have to get new tires ! I will report back on findings on steel painted wheels !
 

GCecchetto

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The big draw of ECO hubs (at least for me) is that it's something that can be done in the driveway in about the same time it would take just to service the hubs. And it's just as easy to revert back to stock. Also factor in the price at around $2500 shipped

Where 3:07's will require pulling the axels, dropping the drive shafts, cracking open the pumpkins, etc, etc. Having someone do the work is pricy (especially if they really know these trucks) and the work is mostly all geographically isolated. The cost of the 307's is historically anywhere from $3000-$5000 for just a pair of pumpkins (yeah, the originally cost about $80 ea at auction but "supply and demand"...or blatant wallet rape depending on your perspective). The price may be falling as people shy away from them in favor of the, IMO better solution of ECO hubs. I'd not saying that 3:07's are still not a good deal at $80 each, I'd just rather the flippers who have controlled the pricing up until now keep them. The 3:07's are FAR more complicated to revert back to OEM should someone wish to do so for whatever reason. And shipping a couple pumpkins across the country is not cheap.

Personally, I'd always MUCH rather support someone who is actually making a product.. opposed to just flipping old surplus (especially when it's for big profit justified by "supply and demand").

ECO hubs are a win/win in my book. There's no question as to which is the better/smarter purchase/install, IMO.

ymmv
And the cost of 307's only gets worse if you have a high pinion rear diff, where that is of no consequence at all with eco hubs.
 

hike

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As mentioned the axles are gross milspec overkill even for one of our trucks grossly overloaded. Because of the weights we typically do run, I do not think loosing the 2:1 hub final will significantly effect their operation.

I think the benefits of dropping the engine RPM closer to engine peak torque at highway speed(60MPH with 3.9 in 6th gear will yield 1517 engine RPM) and cutting the driveshaft RPM IN HALF on these very steep driveshafts far outweigh any possible downsides that I can see… Thats why I was attracted to the concept way back when…

The only place I would be curious to see final performance is in slow speed wheeling. The low speed torque manipulations provided by the torque converter in the Allison are where this combination really shines though. I am sure it will be different, but I do not think that difference will be significantly different/unusable at slow speed Because we have that added 6.93:1 first gear.

Would love to come wheel your truck, but don’t think I am getting to Indiana anytime soon…

You can put me down for a set though:)

edit: Easier to read the tables as screenshots. Forgot how difficult it was to do columns in HTML:)
Hoping to build upon the shoulders of giants...

I may look at things from a different point as my experience comes from Land Cruisers, Land Rovers and Jeeps, not military vehicles. So, wanting to see crawl ratios and inches per minute I built upon @Ronmar fine table and then added in our latest Jeep Wrangler's numbers for comparison.

crawl-ratios-lmtv.jpg

crawl-ratios-jlurxr.jpg

Some thoughts from this:

1– why did they build 2:1 wheel hubs instead of changing the ratio in the transfer when in MODE?

2– the reduction to the crawl ratio is much more significant with the ECO HUBS than the 3.07 differentials.

3– ECO HUBS with the 3.07 differentials in MODE almost matches a JL Wrangler Rubicon Extreme Recon model in 4H for crawl ratio.

4– in 4LO a JL Wrangler changes the shift points, though more importantly changes the throttle action. The pedal is much more subtle in 4LO, less punchy. It makes slowly walking obstacles easier, though I wonder if it reduces the chance for sudden torque changes that may damage the axle shafts?

Any way fun puzzle to work on. With some of the places I'd like to go in the M1078 I am still on the fence, though I really want to get rid of the 2:1 hubs. Point out what I am missing and have yet to realize–
 

Ronmar

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Took me a bit to get my brain around your table, and your gear ratios are a bit off.

1- the transfer is not shiftable. It applies a fixed 1.2:1 to all the input ratios using 3 large gears. They took a 3060 transmission with its 6 speeds(our 2-7) + R and hung the 1.2:1 off the back end. In the upper rear of the transfer they put the C6 clutch pack that brakes a shaft that runs up thru the middle of the trans output shaft and transfer primary gear to the sun gear in the last planetary gear set. This allowed them to squeeze an additional gear out of the 3060 core and provide us with that very low 1st gear.

The only thing selecting mode does is to lock the center diff down in the bottom, and of course limit the top gear to 5th.

here are the final ratios including the fixed 1.2:1
GEAR RATIO CLUTCH

1st 6.93:1 C3-C6
2nd 4.18:1 C1-C5
3rd 2.24:1 C1-C4 + LU
4th 1.69:1 C1-C3 + LU
5th 1.20:1 C1-C2 + LU
6th 0.90:1 C2-C3 + LU
7th 0.78:1 C2-C4 + LU
R -5.00:1 C3-C5
 

NotThatGuy

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I know I’m going to get flamed, but here we go. PLEASE DO NOT ASK ABOUT PURCHASING ACCEPT THRU PM.
I just finished an up grade to my 1078. DELEATED the hub 2:1 gear reduction. I built direct drive hubs that can be
installed in 20 to 30 minutes per wheel. Doesn’t harm the original reduction system,(that can be reinstalled in
20 to 30 min). NO shim changes, ( the shims stay in place).

4 hubs. If there is enough interest…. Sorry for the long post.

Anyone interested in purchasing a set, please post in the sales thread:

A) What Material did you use and; B) Have you an estimated/actual Rockwell Hardness?

Good job!
 

aw113sgte

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I do worry a little in recovery situations, literally twice the torque to the rest to the drivetrain to apply the same force. Really don't want to shred a diff or snap an axle.
I'd be hesitant to do stump pulling or other such activities, with the 2:1, likely traction is the weak link...now it may be something else.
 

Xengineguy

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I do worry a little in recovery situations, literally twice the torque to the rest to the drivetrain to apply the same force. Really don't want to shred a diff or snap an axle.
I'd be hesitant to do stump pulling or other such activities, with the 2:1, likely traction is the weak link...now it may be something else.
I have had customers try stump pulling. (I don’t recommend that !). In first gear traction seems to be the week link so far??
 

NotThatGuy

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How was the 2-3 shift? I have a theory that our 2-3 will be nicer with this configuration due to the way the Allison brings on the lockup clutch in 3rd.

Yea the fill is thru a inner to outer hub mount hole. The amount of oil in the rear is not so critical, any extra you add will just flow back into the main axle housing, with a proper fill of the axle the rear hub heights are maintained automatically

The original instructions say add 11-13 oz of oil from empty, but that was for a different size housing full of the hub gear set. I believe that volume of oil was to set the oil at a particular height in the housing. The other method for filling and checking front oil level is to roll the housing drain plug to 4 o'clock and add oil till it runs out. The O’clock method in the original configuration sets the oil level(bottom of drainplug opening) to just above the bottom of the axle shaft. How much oil it takes to reach the same level in the new configuration I have not yet determined.

The bottom edge of the rear axle fill hole on the pumpkin sets the oil level just below the center of the axle. Differential oil level is considered normal if within 1” of the bottom edge of the filler hole, to the bottom edge when cold. That is between bottom and middle of axle shaft . I would say between these two heights would be acceptable in the front to keep the axle bushing and outer hub bearing properly lubricated And allow room for any expanshion.

With this setup there should only be heat from the bearings, and that should be pretty low…
Good Catch Sir!
 

Ronmar

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I do worry a little in recovery situations, literally twice the torque to the rest to the drivetrain to apply the same force. Really don't want to shred a diff or snap an axle.
I'd be hesitant to do stump pulling or other such activities, with the 2:1, likely traction is the weak link...now it may be something else.
You cannot apply twice the torque to anything, because you do not have it available. With 2:1 hubs, if you are VERY heavily loaded in a max traction situation and against an obstacle/slope you cannot surmount you will apply all your available torque until you reach TC stall. All the drivetrain components had to be able to withstand this force(TC Stall test). The driveshafts are typically the weak link, and they are clearly specced to more max torque than we can deliver. General disorder with his tuned up C7 is closing in on the limits though:) The only thing the ecos do is reduce the possible force you can apply to the wheel by 1/2…
 

GeneralDisorder

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I do worry a little in recovery situations, literally twice the torque to the rest to the drivetrain to apply the same force. Really don't want to shred a diff or snap an axle.
I'd be hesitant to do stump pulling or other such activities, with the 2:1, likely traction is the weak link...now it may be something else.
You worry needlessly. @Lostchain and myself have been going off-road quite a bit. I went through a gully at the beach that was steep enough to scrape the paint off my skid plate and never even went lower than 2nd gear.

Is you truck/trailer/cargo combination in the realm of ~100,000 lbs? If it is you might want to keep the reductions.
 

GeneralDisorder

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1– why did they build 2:1 wheel hubs instead of changing the ratio in the transfer when in MODE?

2– the reduction to the crawl ratio is much more significant with the ECO HUBS than the 3.07 differentials.

3– ECO HUBS with the 3.07 differentials in MODE almost matches a JL Wrangler Rubicon Extreme Recon model in 4H for crawl ratio.

4– in 4LO a JL Wrangler changes the shift points, though more importantly changes the throttle action. The pedal is much more subtle in 4LO, less punchy. It makes slowly walking obstacles easier, though I wonder if it reduces the chance for sudden torque changes that may damage the axle shafts?

Any way fun puzzle to work on. With some of the places I'd like to go in the M1078 I am still on the fence, though I really want to get rid of the 2:1 hubs. Point out what I am missing and have yet to realize–
It's an interesting comparison but a bit of apples to oranges.

First - the biggest glaring difference is the power plant. The C7 in my truck makes 931 ft/lbs of torque - now that number doesn't seem impressive on the surface since the Jeep Wrangler XR with the 392 Hemi puts out 470 ft/lbs and definitely weighs a LOT less than half my M1079 - but it doesn't make that torque at 1450 RPM. The engine torque peak on that wrangler is around 4500 rpm.

And then remember you have an automatic behind that torque so at 1450 RPM with full converter stall we have 1862 ft/lbs going into the transmission input shaft.

Gearing is simply a crutch for a lack of necessary torque from the power plant. If you have more torque from the power plant then you simply don't need more gearing. And our lower RPM torque means we can idle along and crawl at low speed and low RPM using our tremendous torque advantage.

Also the M1078 isn't a rock crawler and never will be. Pull your Jeep toy behind it and it will never notice or care that it's back there. The M1078 will not appreciate jeep trails or rock crawling. That's not it's bag. It's too heavy and too large to play that sport. It's a cargo hauling off-road capable truck. It's meant for unimproved roads, cross country, and maybe a little fording. If there's a mountain in the way the military will fly over it or blast a hole in it, or have the engineers move it out of the way.

As to why they built the 2:1 into the axles - the boundary conditions. An A1P2 wrecker pulling it's full rated load up a mountain..... that's about 95,000 lbs of truck and cargo. Just getting that moving up a very steep grade requires a lot of mechanical advantage. But my M1079 is 21,000 lbs. So at 1/5 the weight it's just not needed.
 
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hike

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It's an interesting comparison but a bit of apples to oranges.

First - the biggest glaring difference is the power plant. The C7 in my truck makes 931 ft/lbs of torque - now that number doesn't seem impressive on the surface since the Jeep Wrangler XR with the 392 Hemi puts out 470 ft/lbs and definitely weighs a LOT less than half my M1079 - but it doesn't make that torque at 1450 RPM. The engine torque peak on that wrangler is around 4500 rpm.

And then remember you have an automatic behind that torque so at 1450 RPM with full converter stall we have 1862 ft/lbs going into the transmission input shaft.

Gearing is simply a crutch for a lack of necessary torque from the power plant. If you have more torque from the power plant then you simply don't need more gearing. And our lower RPM torque means we can idle along and crawl at low speed and low RPM using our tremendous torque advantage.

As to why they built the 2:1 into the axles - the boundary conditions. An A1P2 wrecker pulling it's full rated load up a mountain..... that's about 95,000 lbs of truck and cargo. Just getting that moving up a very steep grade requires a lot of mechanical advantage. But my M0179 is 21,000 lbs. So at 1/5 the weight it's just not needed.
The comparison I am interested in is the crawl ratio. In a vehicle this big a crawl ratio over 50 would be helpful on difficult trails (7+). Moving methodically and steady through obstacles is easier on the equipment and the occupants. For example: I'd like to have ECO HUBS on our rig and take the Road to Hite to camp at The Doll House. The low crawl ratio is giving me pause.

Now if I could reprogram the throttle control in MODE to make it less punchy that would be helpful.

You have much more experience than I do running 48's on a rig. I value your comments—
 
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