Is a Dana 80 strong enough?

Section8

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Ok so here is the thing.
I own what's left of a 1956 M135. I can't restore the truck to original since it is missing to much important stuff.
There is a guy a couple hours away who contacted me wanting to purchase my axles. I am only considering selling since I am wanting a little more modern drive line and have easier accessibility to parts when needed. I have also found a set of Dana 80 axles for sale a couple hours away, other direction of course, for a decent price.
My question is this.
Would Dana 80 axles be strong enough for a bobbed Duece?
I think they are rated for 10000 pounds but will they hold to stock 1100/20r's or maybe even 1600's?
Not sure the weight of stock 1100's but think it's close to 300 pound with rims. 1600's close to 600 pounds?
Will trying to turn that much wheel snap the axle shafts?
Anyone know the axle shaft diameters of Dana 80s? I can't find that info on the net.
Is it a good idea in general?
Plusses include gear options, modern part availability, disc brakes...
Sound off
 
195
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Adams NY
A Dana 80 and Dana 70 are different axles. Some one ton pickups have Dana 80s with Dana 70 shafts. These axles are known as Dana 80 hybrids. If the axles your talking about are true Dana 80s then I would say yes, but no winch, no hauling, and no towing. What kind of budget are you working with. 2.5-ton axles can be had fairly cheap. Even I have some I'm looking to sell.
 

Speedwoble

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Yeah, the Dana 80 will be strong enough for you. The Dana 80 runs a 35 spline 1.5" axleshaft while the 2.5T Rockwell runs a 16 spline 1.56" shaft(Your GM 2.5T axle is 1.75" according to the interwebs). The 16 splines in the in the Rockwell is weaker than the 35 in the Dana, but guys put 1600's on bobbed deuces Also you said you would be bobbing it, so I assume you no longer have intents of it being a 2.5 ton truck. Plenty of guys in the off-road crowd running the 1600's on 1ton trucks with likely more power than the ole 135 has.


Reasons you might not want to consider the Dana: If you are upgrading the power, you will have to evaluate your needs. The Dana stock is going to have 4.10 R&P, so it will be much more sluggish with large tires then the 6.** R&P in the gm axle you have now, or the 2.5T Rockwell. Your front driveshaft runs reverse, so you will have to change your transfer case.
 

Section8

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The axles are true Dana 80s out of a F550.
Even though I could get a higher ring and pinion, 5.?? To 1.
Think I will keep my stock axles for now since I know they will turn the stock 1100s or larger for a while.
I will look for more modern and maintainable axle when mine finally kick the bucket.
Thanks for the input everyone.
 

rustystud

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A Dana 80 and Dana 70 are different axles. Some one ton pickups have Dana 80s with Dana 70 shafts. These axles are known as Dana 80 hybrids. If the axles your talking about are true Dana 80s then I would say yes, but no winch, no hauling, and no towing. What kind of budget are you working with. 2.5-ton axles can be had fairly cheap. Even I have some I'm looking to sell.
I should have said the Dana 70HD which is what the big three used until the 80 came out. They both have the same weight carrying ability and the same shaft size 1.5" . The difference is the disc brakes. Yes they went to a 11" ring gear instead of the 10.5" but they really are the same. Having rebuilt both I can honestly say there really is no difference in performance or ability. Now as far as the Rockwell being the same as the Dana 80, are you kidding me ? Yes the axle shaft is the same diameter but the housing which supports the actual weight is totally different ! The Dana 70HD and 80 have a 4" round housing (1/4" to 3/8" thick depending) which can only support a MAXIMIUM of 11,000 GAWR. The Rockwell housing is over 1/2" thick and can support almost triple the GAWR of the Dana 80 . People get confused about the axle shafts themselves thinking they support the weight. This is not true. In fact 80,000 semi-trucks and busses all have 2.00" axle shafts ! It's the housings that support the weight. Just a side note, the strongest axles factory made are in "Fire Trucks" . They have a Rockwell hardness of 55 and are machined totally smooth to a mirror finish. There is no imperfections or uneven grain for a stress facture to develop . The first time I saw one I thought "this is a thing of beauty !" .
 

rustystud

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Yeah, the Dana 80 will be strong enough for you. The Dana 80 runs a 35 spline 1.5" axleshaft while the 2.5T Rockwell runs a 16 spline 1.56" shaft(Your GM 2.5T axle is 1.75" according to the interwebs). The 16 splines in the in the Rockwell is weaker than the 35 in the Dana, but guys put 1600's on bobbed deuces Also you said you would be bobbing it, so I assume you no longer have intents of it being a 2.5 ton truck. Plenty of guys in the off-road crowd running the 1600's on 1ton trucks with likely more power than the ole 135 has.


Reasons you might not want to consider the Dana: If you are upgrading the power, you will have to evaluate your needs. The Dana stock is going to have 4.10 R&P, so it will be much more sluggish with large tires then the 6.** R&P in the gm axle you have now, or the 2.5T Rockwell. Your front driveshaft runs reverse, so you will have to change your transfer case.

It's not about the power rating of the engine but the axle housings ability to support the load ! The Chrysler 9-3/4" came in the "Hemi Cuda" which had 500 HP ! But you would never put that under a deuce and expect it to support the weight !
I'll give you another example. My TD6 dozer weighs in at 3 tons but the engine has only 85HP . Does that mean I could put a Dana 80 under it and it would be fine ? No way ! You guys who come from a 4X4 or hot rod back-ground need to readjust your thinking. Having started as a car mechanic and then going into the Heavy truck industry I needed to readjust my thinking many times. I remember asking this old fart (which I am now one myself ! ) why I couldn't put a Chevy 454cid into the IHC Transtar 80,000 GVW truck. After all the Cummins engine in it didn't put out the same horse-power as the Chevy. He looked at me like I was from Mars and just walked away muttering something about stupid kids and their stupid questions. What I failed to understand at the time is the torque ability of that Cummins engine. Yes it only put out 250HP but it could out torque that 454cid all day long and then some ! Well the same thing applies to the transmissions and differentials. We are dealing with the "weight" of a large truck, not a pick-up truck.
 

TGP (IL)

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The axles are true Dana 80s out of a F550.
Even though I could get a higher ring and pinion, 5.?? To 1.
Think I will keep my stock axles for now since I know they will turn the stock 1100s or larger for a while.
I will look for more modern and maintainable axle when mine finally kick the bucket.
Thanks for the input everyone.
You sure?
Are the Axle housings square?
I had an 01 F550
With a Dana 110 in the rear with square housing, and whatever the front was.
If I remember was a Dana 60HD front.
Was bigger than a Dana 60 for sure.
 

rustystud

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You sure?
Are the Axle housings square?
I had an 01 F550
With a Dana 110 in the rear with square housing, and whatever the front was.
If I remember was a Dana 60HD front.
Was bigger than a Dana 60 for sure.
All Dana 80 differentials have round housings. The Dana 110 has the square housing like most heavy truck differentials.
 

TGP (IL)

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All Dana 80 differentials have round housings. The Dana 110 has the square housing like most heavy truck differentials.
Correct.
That's my point.
He said a Dana 80 from a F550 ferd.
All the 550 I have seen run the Dana 110 or the newer American axle chink copy.

Also just my opinion a Dana 80 in the deuce weather bobbed or not is too small
And will seriously degrade the truck value!

Tom
 

rustystud

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Correct.
That's my point.
He said a Dana 80 from a F550 ferd.
All the 550 I have seen run the Dana 110 or the newer American axle chink copy.

Also just my opinion a Dana 80 in the deuce weather bobbed or not is too small
And will seriously degrade the truck value!

Tom
I totally agree. The Dana 80 is only rated for 1 ton trucks, not a 2.5 ton truck.
 

porkysplace

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I totally agree. The Dana 80 is only rated for 1 ton trucks, not a 2.5 ton truck.
A F550 is rated to haul more than a M35a2. But a lower GVWR and lighter weight truck.
Maximum Payload 12,660 lbs. (F-550 DRW 4x2)
Maximum GVWR 19,500 lbs. (F-550 DRW 4x2,4x4)
 
195
2
18
Location
Adams NY
Ok so here is the thing.
I own what's left of a 1956 M135. I can't restore the truck to original since it is missing to much important stuff.
There is a guy a couple hours away who contacted me wanting to purchase my axles. I am only considering selling since I am wanting a little more modern drive line and have easier accessibility to parts when needed. I have also found a set of Dana 80 axles for sale a couple hours away, other direction of course, for a decent price.
My question is this.
Would Dana 80 axles be strong enough for a bobbed Duece?
I think they are rated for 10000 pounds but will they hold to stock 1100/20r's or maybe even 1600's?
Not sure the weight of stock 1100's but think it's close to 300 pound with rims. 1600's close to 600 pounds?
Will trying to turn that much wheel snap the axle shafts?
Anyone know the axle shaft diameters of Dana 80s? I can't find that info on the net.
Is it a good idea in general?
Plusses include gear options, modern part availability, disc brakes...
Sound off
Wait a minute... Are you saying you found a Dana 80 steer axle? I don't believe I've ever seen one from the factory. What did that come out of?
 
195
2
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Location
Adams NY
A bobbed Duece weighs 11,000 lbs. Dana 80 max GVWR is 11,000 lbs × 2 axles on truck = 22,000 lbs. That seems like plenty of weight to spare to me. Although they would look kind of funny under the truck.
 

TGP (IL)

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I'm still waiting on what front axle he is going to use.
Ok, a Dana 80 rear is boarder line, Dana 110 much heavier, but there is no Dana 80 Front.
All the F 550 have a Dana 60 HD or Super front Axle which is too light.
Tom
 

Section8

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My Way of thinking was in line with Porkysplace, in that the Dana 80 axles have a GVAW of 11000 pounds which is not a one ton rating unless there is a new system of math out there that has come into place since I was in school 26 years ago. My stock M135 has a max of 10000 pounds with the tandem set up. Most F550 stock have more hauling and towing capabilities than my stock M135.
The guy that has the Dana axles for sale said they came out of a F550 and both front and rear are Dana 80s, 4x4 truck.
If I knew how to post links in would but it is also on another site that has open bids and I am pretty sure that is a no no on our rules.
As Rustystud mentioned before, I know the axle housing is what supports the vehicle weight and payload, and I would hope most people know it is torque more than horse power that pushes a vehicle.
I would probably never even reach either axles max payload rating, my stock or the Dana, but was more concerned about twisting an axle shaft off and having a large rubber missle flying into on coming traffic.
 

TGP (IL)

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Metro East IL
You need to make sure he (axle seller) knows what he is talking about.

Dana 80's are not in Ford F550 or any other brand 5500.
There also is no Dana 80 front anywhere.
Dana 70 front in the late sixties early seventies, then Dana 60,Dana 60HD, and Dana 60 Super since.
Ford used Dana 50 in the front of 3/4 tons which most don't even know existed.

Dana 80's rear are now used in one ton trucks of all makes.
My 99 Dodge 3500 has Dana 80 rears.
The F550 and 5500 have Dana 110 rears or American axle equivalent.

Also FYI
Remember US government derates everything.
The Deuce and half will handle well over it's rated capacity.

Tom
 
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