Swapping in a rear Dana 70 or Corporate 14

[niferous]

I have been wanting to change out my axles for a while now and I would appreciate some input regarding my choices. Mainly I want the better gearing of a 4:10 or 3:73 and I would like to have the 8-lug 16" wheels so that they match my Suburban and my I've been wanting an M101A2 trailer for a while and I'd like to be able to swap tires between the three as needed.

I've got a local lead on two different rear axles that I'm thinking about swapping into the rear my M1009. One is a Corporate 14 out of a mid 80's farm truck and one is a Dana 70 that a guy already modified to fit into a 1978 Blazer. The one guy with the Corporate 14 only wants $150 and it's complete with brakes and even has some tires with steel rims on it. So which do you guys think is the better choice? Right now I'm waiting for the guy to call me back on the Dana 70 so he may throw out a price that is way out of the ballpark. I'll update the thread when he gets back to me. But strictly from a mechanical stand point which do you think would be better?

Now on the front I was thinking of either doing a Dana 44 or I read on another thread on here that I can just convert my front 10 bolt to an 8-lug. Keep in mind that I'm not thrashing this truck or going out rock crawling. I just want a different gear ratio and the ability to swap tires around. I run 32" tires on the M1009 now and that's what I'm sticking with. So I really think that that factory front would do. The only reason I'm wanting a different rear axle is that that ones I've found for sale are usually about as expensive as the parts to re-gear my current axle. I'm also not afraid to spend some extra dough though on the front so I'm open to other suggestions there beyond just converting it to 8-lug and then re-gearing it to match the rear axle.

So what do you guys think?

 

[niferous]

OK the guy with the Dana 70 rear called me back. He said it's an open axle (no locker) and that he shaved the spring perches off. He also said he has a Dana 60 front with 4:56 gearing in it. He said he would take $500 for both. Sound like a good deal?

 

[nhdiesel]

The price sounds good on the surface, thats a steal considering it includes the fron 60. BUT it won't end up saving you any money if you are looking for 3.73 or 4.10 gears. 4.56 with stock or near stock tires in a diesel truck, and forget using the highway. For that rear, consider the time to install spring perches, get the pinion set correctly, and fab up shock mounts if needed. If its not work you can do yourself, it will add to the cost.

Usually the cheapest and easiest way to get what you are looking for is to either find a part's truck or buy a pair of axles from the same truck that bolt into yours. For a Blazer, the front is easy- and 1/2 through 1-ton fullsize GM truck will bolt right in. For the rear...well I'm not up on my GM dimensions that well, but I believe all the 1/2 through 1-ton, except cab & chassis, will bolt in. Worse case, the rear axle's spring pads may have to be moved.

I'm not sure about your area, but I know I can find 3/4 and 1-ton GM trucks all day long for $500-$1000 each, still running and on the road (but rough bodies). That would give you the axles, wheels, a ton of other spare parts, then scrap what you don't need for a few dollars back.

Jim

 

[kassim503]

I would go for the 14 bolt for 150 vs the 70 for 500, just because setting up the rear axle to bolt on is going to be too much work.

Just a word of caution if you do follow the 14 bolt path, measure the distance from spring perch to spring perch, I know somewhere in the 90's the gap got a little smaller. And stay away from dually's and cab and chassis trucks, they are shorter.

 

[kndllmtt]

 

[davo727]

Yeah put the 60 front in it and the 14 rear. If he insists on a package deal including the 70 rear just resell it to somebody else

 

[Recovry4x4]

Folks that know they have 60Fs usually don't sell them for $500. I'd have a looksee. It might even be a closed knuckle 60F which I would advise against. The 14 bolts are strong, plentiful and cheap. Lockers can be had much cheaper for the 14B FF than the 70R. If its a true 60F out of a one ton truck with disk brakes, it's a great price and worth buying even if you don't use it. I just bought a 14 bolt FF off of craigslist for a whopping $80.

 

[doghead]

$80 must be the minimum bid on Clist....

btw, my new to me, 1990 Dodge tug has a Dana 70, Detroit locker and 7.17:1 ring and pinion. I'm told I can re gear this thing to a 4.10:1. Does anyone have a set of 4.10 gears for this axle that I can buy cheap? I am considering "un bobbing" the tug into a daily driver.

I suppose without an overdrive transmission, my best choice would be to just use a different axle with about 2.70-3.08 gears. Just thinking outloud here.

 

[Recovry4x4]

Actually it was $20 below minimum bid. Gotta love CL.

 

[nhdiesel]

$80 must be the minimum bid on Clist....

btw, my new to me, 1990 Dodge tug has a Dana 70, Detroit locker and 7.17:1 ring and pinion. I'm told I can re gear this thing to a 4.10:1. Does anyone have a set of 4.10 gears for this axle that I can buy cheap? I am considering "un bobbing" the tug into a daily driver.

I suppose without an overdrive transmission, my best choice would be to just use a different axle with about 2.70-3.08 gears. Just thinking outloud here.

Double check that 70, because I thought those used a rear 80. I could be wrong though.

For gears, you would want something in the low 3s without OD, such as 3.08. I have a '96 with a Cummins and OD, running aprox. 32" tires (was 265/75/16, then 245/75/17) and with 3.54 gears I had an eeconomical cruising speed of around 75 mph. Any higher and mileage dropped quick. When I went to 3.73 gears (when I swapped to '04 axles) that speed dropped to around 70.

As long as you aren't towing anything too terribly heavy 3.08 will work just fine.

Jim

 

[niferous]

I think I'll probably just pick up the Corporate 14 and then keep my eyes and ears open for a suitable front axle. A Dana 60 would sound cool but honestly it's way more axle then I need and I'm concerned about re-gearing it and also if it's the undesirable kind. I do have a few questions about the Corporate 14 though.

- How can I tell if it's a full floater or not?
- Is there anyone near Houston that has ever rebuilt one that can show me how?

On the rebuidling part it may not need it but I'd still like to put a Detroit Locker in there if it doesn't already have one. I've changed the fluid on a rear dif before but that's it. Past that I have zero experience working on rear ends but I would REALLY love to learn. Free lunch and some booze to anyone who helps out.

 

[nhdiesel]

Rear Axle Identification | Ventures Truck Parts and Equipment L.C.

In the photos, the axle on the left is a semi-floater. There are no visible bolts, just the wheel studs and brake drum. The photo on the right is a full floater. There will be 8 bolts in a circle in the center of the bolt pattern. You can actually pull the axle shaft without pulling the drum. In fact, you don't even have to remove the wheel to change an axle or rebuild a differential.

Jim

 

[niferous]

Thanks. I have actually seen one and worked on one before but didn't even realize that was what identified it as a "full floating axle".

 

[niferous]

Ok the guy with the Corporate 14 is a semi floater. He said he'll do $80. Should I do it?

 

[kassim503]

I would quickly look around for a reasonably priced full floater before making that decision. Even though im sure a semi floater would work alright for your application, the full floater is indestructable

 

[Cucvnut]

A Semi floater 14Bolt is a good axle it gets a bad rap because its brother the 14ff is king in off road world. Fourwheeler just did a rebuild on the axle. it will hold up to 37's i ran them on my suburban with a 14SF. If your not going loco with big tires a 14SF will be fine. As for the front you will need to regear the 10 bolt to match the rear axle. or find one that has the correct gears and swap them.

 

[nhdiesel]

If the 14sf has the gears you want and is in good shape, I wouldn't turn it down. you said you don't plan to use the vehicle hard. If you would have to spend on gears, bearings, or other parts, then I'd say before investing more money in the SF, look for a FF instead.

Keep in mind that although the names are similar, you are talking about two completely different axles. They just share the same name because they happen to have the same number of ring gear bolts. the 14 FF uses a 10.5" ring gear, and the pinion is removable out the front by a ring of bolts. The pinion is also supported by 3 bearings instead of the typical 2, and one of those bearings supports the end of the pinion (the gear has a bearing on each side of it).

the 14SF uses a 9.5" ring gear, has only 2 bearings for the pinion, and the pinion gear is unsupported. This is a fine upgrade from a 1/2 ton axle, but its not even really a 3/4 ton axle. Trucks with a 14SF are considered "light 3/4 tons". As long as you aren't hauling heavy loads in the bed of the truck or pulling 10k+ lb. trailers, or trying to turn huge tires, it should hold up fine.

Jim

 

[bronconut]

i would suggest holding your money and finding a set of full floater 3/4 axels front end rear. i believe 1973 to 1987 will work in the 1009, they are cheap and plentiful, also a bolt in deal, you will need to either change your u-joint on the rear dshaft, cant remember the number but i think i still have the box floating around in the shop some where, or you could take rear shaft to a trans shop to have new yolk put on, but u-joint is cheap and easy. for the rear axle you will also need larger u-bolts other then that bolt them in and go

 

[niferous]

Hmmm. Man decisions decisions. I guess I'll wait around for a Corporate 14 full floater. I know me and I know I'll want the best I can get within reason. Now the 14 SF is good but the 14 FF isn't much more expensive and they are out there. I guess I'll wait. On the front if I can find a good Dana 60 with the right gearing I'll do it. We'll see and I'll update this thread as we go along.

 

[Recovry4x4]

I upgraded the axles in my burb. I put in a semi floater and although it has worked flawlessly, I never stopped looking for the full floater. Found one for $80. Haven't installed it yet but I got it!