Axles that can be swapped in place of the stock axles

It all comes down to what you want the truck to do.

Taller than 38" tires, hi power engine swapped in and planning to climb walls. Then, the stock front axle is probably not stout enough to last. Especially if a front locker is installed.

Stock engine, hi powered ground pounder, 38" tall tires or smaller, no front locker and no hard core beating planned. The stock axles will probably last longer than the sheet metal.

The 5.87 gears in the stock axles are what lead most people to swap. Plus the closed knuckle, king pin, drum brakes and $200+ lock out hubs. By the time you change to a more street friendly ratio, put on lock out hubs and think about disc brakes. A set of CUCV D60/14b axles with all the goodies could be purchased with all the good stuff and money left over.

It all comes down to what you want to do. CUCV axles have tripled in price over the last 8 years or so. Now it is a dead even swap money wise.

I left mine stock, put on lock out hubs in front, a locker in the rear and my 396 Big Block has a NV4500 bolted behind it to turn the XZL tires. But, I am limited to 54 mph because of the NP200 tcase on long trips. The axles physically aren't the problem, just the gear ratio inside. A NP205 is my answer to the speed thing and the axles will be left alone.

Sorry guys, but Im ignorant about all these numbers and such describing axles.

I'm not into going straight up with the Jeep, Just haul with it and maybe pull a 5th wheel at some point later.
I don't know just by looking at a particular transfer case if its' a np200/np2xx OR 14 bolt from a 70.
SO, if I go to a 'yard'/pull it, What year ___ do I look at?
Some describe a 'dually' rear.. Does that mean you adapted your Jeep for a dually axle or did you mod it to have just one tire on each side?

Does anyone know or have pics of axles/t-cases that come with 4.10 gearing?
Here in the Memphis area, there are literally TONS of HD trucks around in the yards but don't want to be swapping a 5-700lb rear more than once

E

E,
The higher the number, the more mechanical advantage the engine has and the more pulling power the truck has. That is how the stock 120 hp engine is able to pull 1-1/4 tons of cargo off road. Gears, not power make it happen.

The lower the number for the gear ratio, the more highway friendly a vehicle is. However, it also becomes more pulling limited. The M715 was designed to haul 2500 pounds off road up to around 30 mph. Then to be able to run down the road at convoy speed of maybe 45 mph. It does that perfectly.

People wanting to run faster, have more powerfull engines installed or that don't care about the pulling power. Often want to get rid of the stock 5.87:1 axle gear ratio.

Gears can be bought all the way down to 4.56:1 gears. However, here is where it gets complicated. The Chevy M1008, M1028, M1031 CUCV 1-1/4 ton CUCV trucks all came with 4.56 gears in them. They also had a locker already installed on the rear, normal 8 lug bolt patterns for the rims, open knuckle front axles, front lock outs, disc brakes on the front and rear disc kits available for not much money. That is the Dana 60 open knuckle front/14 bolt corporate rear mentioned above. 1977 to 1991 depending on the model 1 ton GM trucks had these axles. However, lockers on the rear only happened on the M trucks.

There are a lot of semi floating 14 bolt rear axles out there compared to the CUCV full floating rear.

I would suggest you rear as much of the modified section post about axles and truck builds as you can to get a better understanding of all this because I really didn't scratch the surface. Just tried to explain the basics.

Barrman, I'm 'all up' with the gearing ratios, it's just terms like CUCV, M1008 yadda yadda that get me all cornfused.. I have no idear whatcher tawkin 'bout!!

I would LOVE pics of these rears (NO pun intended) I've pulled up some seaches but would like a link to a list with pics/casting #'s and Maybe even U-joint sizes.

There are a couple of LARGE pull a parts here in the Memphis area, and with all of the trucking here also, there's tons of vehicles that can be 'sourced' for parts. That is if The diff cover is still on them..
SO, I need to print out some pics of transfer cases and rear ends, memorizing them before I crawl under dozens of trucks.

I'd just hate to buy something that I DON'T need..

There were others that said to ask questions.. SO there..

Sorry, I'm in a goofy mood.
Errol

Google images would be your best bet. Do a Google image search for the CUCV and such and you will see what Barrman is talking about.

Questions are indeed welcomed and encouraged, but an effort at self-help will go a LONG way here on the Zone. ;)

As for rear axles you can pick up at the yard, look for a tab on one of the differential cover bolts. That's usually where the gear ratio is indicated. If the cover's off of a wrecking yard axle, I'm probably going to pass on it anyway, but you could count the teeth to determine the ratio.

OK, the way some talk of these axles is like they know some black magic telling them what gears are in them.
I'd doubt that 'yards' will let you pull off every cover off draining all the lube out that you'd be interested in.

Tried to look for the little tabs stating gear ratios on the cover bolts that are either rusted or broken off, and some CODE on the info plate that needs to deciphering..

Are those the only two ways of getting the ratio?
E

The ratio is just a way to represent how many times the drive shaft turns for every time a tire goes around once. Grab the drive shaft yoke (Pinion) and turn it around and around until the tire/axle shaft/brake drum on one side goes around 1 time.

Did you almost make it 4 times around? 3.73 gears.

A hair more than 4 times around? 4.10 or 4.11 gears.

Did it do about 4-1/2 times around? 4.56 gears.

Almost 6 times around? 5.87 gears.

3-1/2 half times around? 3.42 or 3.55 gears.

Just a hair more than 3 times around? 3.08 gears.

There are only so many number of teeth that can be on each gear inside the differential. The list I just made I think are all that could be combined for a 14 bolt.

Now that I have it stripped down to a rolling frame, I'll use some tape and roll her around.

I've gotten messed up before by trying to do that with both tires off the ground and someone mentioned to have BOTH tires on the ground.. (Didn't make sense to me at that time either) but I couldn't argue because for some reason, it was off like almost 3/4 turn..

At least I'll only have to do one end.:lol:

I still think that there should be an axle 'sticky' showing them WITH CLEAR pictures!

Errol

Here is another write up that says the same thing in a little bit different way:

http://www.jedi.com/obiwan/jeep/misc/gearratio.html

so im thinkin about an axle swap and have a quick question. For those of you that have 2.5 ton rockwells, what sort of highway speed are you able to maintain? From the research Ive done, there are no re-gear kits available for the 2.5ton rockwell that would allow you to change from the stock 6.17(i think) down to 4.56 or something more suited for highway speeds. only reason i ask is they are beefy axles and i found a pair for cheap. since i eventually want to run 46" tires it might be a good upgrade for me. any thoughts?

with rockwells that have stock gears, 46 inch tires a T400 tranny with NP205 TC and a 454 I can maintain right around 62 or 63 mph. There is a company called ouverson engineering that makes a gear kit for the axles. I think its in the mid 4 range but they are also $1200 each. I paid less then that for both my axles.

Tyson, Take a look at Overson. they have just about anything you could want for a 2.5 rockwell. o and the ratio you refered to is 6.72 stock ratio and they now have a 4.90. Not cheap but it is out there to be had if you really want it.

http://www.ouversonusa.com/gearsets.html

awesome ill check it out. I love this forum, everyone is super helpful and happy. Ive been on other forums where all people do is argue and pull out tape measures to see whose ______ is bigger.

Anyway, Thanks guys!!!

I just bought a 68 M715 and swapping the rear axle is the first thing that I want to do. My skill level makes a newb look smart but I am a pretty quick learner. I want to do this right and I have a couple questions reguarding the Dana 70 off a GM dually van.

1) Is there a specific model year van that has this axel? Or better yet is there a part # for that axel? I live in Houston, Texas and I went down to the salvage yards today with this information in hand. I found GM dually vans out the ass ranging from 1997-2009, but I dont know which one to pick. They all look the same but yet they all look a little different. When I told the guys what I was looking for they acted like I ws stupid because I didnt have a specific year.

2) Once I know what year model vans I need to be looking for how do I know if its a good axle? They all look like and are covered in rust. I dont want to buy an axle, put it on and then have to repair it anyways. Are there certain things to look for in a good quality axle?

3) Not knowing if it was even the right axle, I bartered with a few of the places just to get an idea of their pricing. I got pricing from $300-500. Is that a good price to pay for an axle?

Welcome to the Zone. Please try to keep the language suitable for any younger kids who might be reading over our shoulders.

Why do you want to swap just the rear axle? A 4x4 needs the front and rear axle to be the same ratio. Otherwise, it will kill gears and the transfer case real fast. You would be better off finding a donor truck with the front and rear axles you want. That way you get drive shafts and such too.

To answer your exact question. A full floating corporate 14 bolt rear axle is the one everybody pretty much agrees on as being the best rear axle smaller than a Rockwell for a big truck. I would recommend doing internet searches for this type of axle. Look for pictures so you can ID them. There are also a lot of threads here on the Zone about them with pictures.

Not exactly on topic but what axles would be able to handle 42-46" military rubber with a 6bt?

Im looking for a 12v cummins in a dodge truck and transplanting the drivetrain. The diesels come with a d80 out back and a d60 up front. Not sure how well they would transplant. the wms to wms of the rear is 70"....so I think they could work. I may have an issue with pass. v. driver drop though, because idk if the stock transfer case could handle that scenario.

Any one ton axle will handle that size rubber. If you are really going to be hard on them most axle shafts can be upgraded to make them even stronger. Put some good lockouts on the D60.

As long as the axles are SRW then you wont have major issues. There are way to many variables to tell you exactly what problems you may encounter. Spend some time looking at both trucks and taking some measurments and you will know within reason what needs to be done.

Get a D60 with pass drop if you want to use the stock Tcase or get a ford divorced Tcase.

How strong are the stock T cases? I am hoping the Cummins will have plenty of power stock, but thats still over 400lbs of torque. My other idea is to get a dodge np205 that will bolt straight to the dodge tranny and be pass drop.

Why dont more people use the stock axles? They are D60 and D70 no? Why buy a new D60?

The Dana 70 from a CJ10A is stoll one of the best choices with its width and 4.88 gearing. There is one in PA for $200.

Quote:

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Originally Posted by Thoner7

Why dont more people use the stock axles? They are D60 and D70 no? Why buy a new D60?

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The D60 in the front of an M715 is roughly of the same strength axle-wise as a D44. It has smaller shafts than a common D60 used in the open knuckle version. It also has the oddball wheel bolt pattern, which can be a hassle unless you don't mind running stock rims with tubes, or making/modifying/or having custom made rims for them. Then there are the drum brakes. The stock axles do work OK for what they are intended for and were pretty much bulletproof in a stock truck with low horsepower like the original Tornado. Larger tires and more horsepower will show some of their shortcomings a little faster. The D70 in the rear has a weird offset for the ring gear and that makes gears and lockers a little more difficult to find and a lot more expensive.

The stock transfer cases are NP200's and are as strong as an NP205 and are identical in many respects. The NP200 does make noise with the stock right rear output and will have heat problems with stock gearing. The noise can be overcome by relocating the output to the center and the heat issue will fairly well go away with more streetable gears.

Okay so I finally got the axles for my truck. I found a guy parting out a 1993 Chevy 1 ton dually and aftermarket 45 and aftermarket 456 gears. He also has the transmission and other stuff from the truck for sale. be oka or should I swap the transmis out as wel? If so will that transmission even fit in the truck? FYI I only paid $200! Springs shock Springs shocks brakes everythin everything included! 14 bolt full float rear and Dana 60 front.

you dont want DRW axles.

you should start a thread with your questions, what you have and what you want to accomplish.

Anyone know what year of VAN that rear axle is?

Randyscycle
You mentioned moving the NP 200 output shaft to the center.
I am unfamiliar with the NP200 since just getting involved with an M715. I am very familiar with the GM NP205. How does one go about moving the rear output to the center other than moving the transfer case inboard?

Quote:

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Originally Posted by renpens

Randyscycle
You mentioned moving the NP 200 output shaft to the center.
I am unfamiliar with the NP200 since just getting involved with an M715. I am very familiar with the GM NP205. How does one go about moving the rear output to the center other than moving the transfer case inboard?

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Welcome to the zone, BJ's offroad offers a kit to move the output. There may be other ways, I'll let others chime in

I think you are having a communication failure. The stock NP200 is just about the same basic case as a NP205. Where the big aluminum cover on the rear of the NP205 is the NP200 has another rear output yoke. That other output yoke is where the stock M715 drives the rear axle.

Switching the rear drive shaft to what is the rear output yoke on the NP205 is what people mean by putting it in the center.

This here is what is being talked about, see the rear output is on the right. Move it to the center.

http://img.photobucket.com/albums/v6...5/P1040329.jpg


http://img.photobucket.com/albums/v6...5/P1040326.jpg

Would the axles from a 88 chevy suburban 2500 fit or able to make fit?

Quote:

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Originally Posted by Kaiser68

Would the axles from a 88 chevy suburban 2500 fit or able to make fit?

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I have the perfect setup for a M715 if anyone is interested, Wide Dana 70 from CJ10A flightline tug (77", 4.88 with Gov lock) and a Dodge DRW Dana 60 front (4.88 and open). They were going under my red M715 but when I bought Spicer Gear's orange brush truck with the 6.2/NV4500 I used a Chevy front 60 and van 14 bolt with 5.13 gears. Axles have just been sitting. Someone make me a decent offer and there yours.

Richard

Pm me how much you looking for

I recently acquired a M715 and want to replace both axles with Unimog axles. I want to know if this can be done or not and what Unimog axles will be perfect for replacing the original ones.

Here ya go:

http://www.m715zone.com/vb/showthrea...ghlight=unimog

Scott

Has anyone done Ford superduty axles? the early (pre coil) ones seem to be pretty close, front spring pads seem to be within an inch and the rear calipers seem to clear the 715 leafs.....

Came from a mid 80's Penske rental delivery cube van. PM me for price and details. Located in upper Michigan.
http://i1301.photobucket.com/albums/...ps0eab0edc.jpg

anyone try 1990 dodge dana 60 front and rear?

Quote:

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Originally Posted by sshannon74074

anyone try 1990 dodge dana 60 front and rear?

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Tried 93, rear wouldn't work with springs in stock location, front might but these axles are really narrow. Id go chevy

Prospecting a 1996 3500 srw as a donor truck for my m715 .... Rear axles front axles breaks , steering ... Etc etc ... It is not 4wd ... Would this be worth it to buy the whole truck 128,000 miles ... 2800 for truck in tact ... ? Any advice would greatly be appreciated !

Has anyone posted up the stock spring perch center to center measurement? I haven't seen it anywhere, but it would be helpful to be in this thread or the one Brute has for axle specs....Thanks!

Quote:

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Originally Posted by ray steadward

Has anyone posted up the stock spring perch center to center measurement? I haven't seen it anywhere, but it would be helpful to be in this thread or the one Brute has for axle specs....Thanks!

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It is posted here somewhere...
But I dont have it handy.
I had to look it up several weeks ago, and wrote it on something, did my tests and moved on.

Let me know if You want the front or rear axle measurement, and I can actually measure what I have sitting on the used parts rack ( 2- stock 70's ) (1- stock 60 ) a newer Dana 70 HD with more splines, 8 lug and drums (1) and a 14 bolt AAM 1050.(disk , with 8 bolt lugs)

One of the latter 2 axles was only 1/2 inch off stock on the perches, I do remember.. and could have used it as is...
If I wanted 8 bolt lugs on the rear and carry 2 spares :(

I can get those measurments for you in the AM, unless someone has the exact specs handy again.
I think I was using WMS to WMS, and then also the perch width in my tests...
But I slept since then.

one more thing to consider is the "offset" of the pumpkin ( Carrier ).. as they vary from stock as well !

can anybody tell me if the 1977 Dodge cucv axles work??? I found a possible donor truck if they will.