Axles & Drivetrain

N1VSM · Post by **N1VSM** » Thu Mar 05, 2009 9:04 am

A few questions. Given a healthy 230, tranny & transfer:

Is there a way to modify the stock 3rd-members to make them locked full time (both wheels getting power)? It seems like giving power only to the wheel that slips is a stupid idea. I don't have the money (who does??) to install lockers and rebuild the pumpkins at the same time.

What would be the drawbacks to doing this? Broken axles? Decrease in mileage (that's a given, I suppose)?

I know some have replaced their axle units with Danas. Here I'll flaunt my technical ignorance and ask what is a Dana?

Does switching to road gearing and/or 1000x16's significantly increase the probability of a broken axle? If I switch over, should I replace with hardened axles?

To quote Paul: "discuss"

Lifer · Post by **Lifer** » Thu Mar 05, 2009 9:23 am

It is relatively easy to convert your differentials to full-time lockers. Unless you plan to use your truck only in the dirt, however, it is not a good idea. The purpose of the differentials is to allow the outside wheel to rotate faster than the inside wheel when cornering or negotiating curves in the roadway. This saves much wear and tear on the tires and improves handling. (A locked front diff will greatly increase the amount of effort you will have to apply at the steering wheel...especially on pavement.) Locking diffs are also hard on axles (much more prone to breaking when least desired). My recommendation would be to go with the bone stock setup, which is quite adequate for the type of work our trucks were designed to do. If you simply must "play in the dirt and rocks," a selectable locker is the only sensible way to go. That way, you can open your diffs up for the road trip to and from the "playground."

k8icu · Post by **k8icu** » Thu Mar 05, 2009 11:35 am

I have to agree with Lifer on locking diffs.

As for your other question Dana is the name of the coperation that makes axles. The M37s axles were made by Dodge and there is no Dana equiviliant, though many have swapped a Dana 60 axles in place of the Dodge axles with some modification. You can fine Danas on Fords, Dodge, and Chevy trucks. For example the M880 Dodge truck of the mid 70s had a Dana 60 rear axle and a Dana 44 HD (heavy duty) front axle. The M715 (the replacement to the M37) had Dana 70 axles. I believe Jeeps had a Dana 35 or 40. The number is the model number of the axle.

Other axles would be Ford 9" and a GM Corp 14 bolt. 9" the size of the diff in the ford very popular with the drag racing crowd and the GM 14 bolt is the number of bolts holding the diff cover on. The 14 bolt is very close to the Dana 60. CUCVs have a Dana 60 front and GM 14 bolt rear for example.

Post by **Cal_Gary** » Thu Mar 05, 2009 12:49 pm

Some of the bigger Jeeps also had Dana 44's-Trucks TV did a build on one a few years back.
Gary

W_A_Watson_II · Post by **W_A_Watson_II** » Thu Mar 05, 2009 4:32 pm

N1VSM,

My M currently is an open Diff (soon to have an ARB locker, I hope).

This picture is from the M when I bought it, with the stock 230-6.

This photo is from this past year, with the 318-V8,

Both are the (short) passenger side axle. Be very very careful if you make it a full time locker, even on soft dirt, you will likely break an axle.

jbxx · Post by **jbxx** » Thu Mar 05, 2009 5:35 pm

Jeep Dana' came in many types.
see:
http://www.offroaders.com/tech/jeep/Jee ... -guide.htm
J.B.

jbxx · Post by **jbxx** » Thu Mar 05, 2009 5:38 pm

If I was going to swap out I would probably go with
Dana 60 rear and 44 front or 60/60 .
I am not speaking from doing this though I am only going by capacity.
j.B.

Wayne64 · Post by **Wayne64** » Thu Mar 05, 2009 8:07 pm

Down and dirty, but you will break axels. Old skool back in the 60s if you wanted full time posi you welded the side gears in the diff to the carrier.

Post by **Cal_Gary** » Fri Mar 06, 2009 6:43 am

Dang Wayne! Bust out the Hooker headers and the Moon hubcaps!

Gary

Lifer · Post by **Lifer** » Fri Mar 06, 2009 8:53 am

Hmmmm! Wonder what Lakes pipes would look like under the running boards of an M37?

MSeriesRebuild · Post by **MSeriesRebuild** » Fri Mar 06, 2009 9:43 am

N1VSM wrote:A few questions. Given a healthy 230, tranny & transfer:

Is there a way to modify the stock 3rd-members to make them locked full time (both wheels getting power)? It seems like giving power only to the wheel that slips is a stupid idea. I don't have the money (who does??) to install lockers and rebuild the pumpkins at the same time.

What would be the drawbacks to doing this? Broken axles? Decrease in mileage (that's a given, I suppose)?

I know some have replaced their axle units with Danas. Here I'll flaunt my technical ignorance and ask what is a Dana?

Does switching to road gearing and/or 1000x16's significantly increase the probability of a broken axle? If I switch over, should I replace with hardened axles?

To quote Paul: "discuss"

Just do the smart thing, 2 choices fall into that catagory, leave it stock or install the ARB's.

Josh · Post by **Josh** » Mon Mar 09, 2009 8:04 pm

I have "Danas". A pair of 60's, to be exact. The rear has a worn out limited slip. I can't say enough about the swap, best thing I have done. Much stronger then the original axle, and you can get just about any ratio. Expect to pay about $1400 for a good working used pair. Avoid the cosed knuckle dana 70 front, it is weak (it is found in olders 60's dodge 3/4 and 1 ton trucks, and the M715). You want the one with the open knuckle and U joints. Other benefit is the front disc brakes. Only drawback is that it takes some fair modification to the front to make it fit. In my rebuild thread in teh main forum I discuss how to do the swap.

As for your idea, I am planning on putting a lockright locker in the rear, it is an overunning mechanical locker, and a detroit truetrac in the front. It is a torque biasing differential, much like a torsen that you can run on dry pavement and it wont do the funny stuff that regular lockers do, as it isnt really a locker, just a torque biasing gearset, but provides miles more traction, assumin both wheels of that axle are in contact with the ground.

Juan · Post by **Juan** » Tue Mar 10, 2009 4:18 am

FWIW I don't know up there, but down here all M-715 came with Dana 60s front axles. Of course, closed knuckle ones.

MSeriesRebuild · Post by **MSeriesRebuild** » Tue Mar 10, 2009 8:20 am

Juan wrote:FWIW I don't know up there, but down here all M-715 came with Dana 60s front axles. Of course, closed knuckle ones.

You are correct, all US M715 series trucks have a Dana 70 rear & a Dana 60 front closed knuckle.

Josh · Post by **Josh** » Tue Mar 10, 2009 9:34 am

ah, I thought it was a 70... either way, stay away from closed knuckle anything. Even deuce axles.

Axles & Drivetrain

Axles & Drivetrain

Re: Axles & Drivetrain