The1980BEAST
1/2 ton status
What are y'alls 2Cents on the Dana 70 rear axle? I'm looking at axles now, and I know I want a Dana 60 front just wondering the difference between a 14BFF and D70 rear
CK5
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Brotherhoods opinion on Dana 70
- Thread starter The1980BEAST
- Start date
the 70 is just as strong as the 14, but the 14 is cheaper to build and easier to find...
1BEATK5
1/2 ton status
i would shoot for a 14b over a 70.
i have broken 2 d70s. no 14bolts. that 3rd pinion bearing is the deal maker. both my 70s had pinion bearing failures.
my .02
auto trans-small block- big tires. = either is fine
man. trans-big block- really big tires = 14 bolt
14ff = cheeper locker/faster setup of gears and close to 10x more comon for parts in our style trucks.
D70HD would be better choice to run with H1 wheels.
I have broken 2 Dana 70 shafts and twisted 3 so I would say the GM 14 bolt is a little stronger. There are many different Dana 70s, main differences are axle tube diameter and bearing size. Around here 70s and 14 bolts are the same price and upgrades cost about the same. Figure out what width you need, they both have different widths.
Only depends on what the OP's intended use for his rig is. If he's building a street queen, a 70 will be just fine. Even up to mild off roading with a generous foot on the go-pedal.
Now if he was building an all out rock crawler, etc., then I'd say to use a 14FF.
Now if he was building an all out rock crawler, etc., then I'd say to use a 14FF.
The1980BEAST
1/2 ton status
not a rock crawler... Mud slinger
Indy4x4Fab
1/2 ton status
ive only seen one 14 bolt fail ever i have seen 20 or 30 do 70s fail. and the 14 that failed was replaced with a pair of rockwells. 14s a tuff as hell only axle tuffer then a 14 in the same light duty range would be an 8 lug dana 80.
14 bolt
pros: Easier to set up, strong generally more available as a direct bolt in for a lot of Chevys and a larger diameter pinion shaft.
cons: Hangs a litle lower than a 70, fewer gear ratios available, gov-bomb.
70
pros: A little better ground clearance, strong, lots of sources outside of GM products, ratios as low as 7.17, better selection of limited slips than a 14 bolt.
cons: Several different 70s with different pinion offsets, different axle splines, different carrier bearings, different pinion bearings, more of a pain to set up gears than a 14 bolt, smaller pinion stem.
If you can get one a lot cheaper than the other get that one, if you need gearing lower than 5.38 you need a 70. If they are close to the same price and you don't need the lowest gearing possible get a 14 bolt.
Gus
pros: Easier to set up, strong generally more available as a direct bolt in for a lot of Chevys and a larger diameter pinion shaft.
cons: Hangs a litle lower than a 70, fewer gear ratios available, gov-bomb.
70
pros: A little better ground clearance, strong, lots of sources outside of GM products, ratios as low as 7.17, better selection of limited slips than a 14 bolt.
cons: Several different 70s with different pinion offsets, different axle splines, different carrier bearings, different pinion bearings, more of a pain to set up gears than a 14 bolt, smaller pinion stem.
If you can get one a lot cheaper than the other get that one, if you need gearing lower than 5.38 you need a 70. If they are close to the same price and you don't need the lowest gearing possible get a 14 bolt.
Gus
Not really true.
The 14 bolt has bigger shafts at the splines than the bigger D70's (1.625" vs. 1.5", which may not sound like a big difference but in torsion that's almost 40% more strength at the splines).
The 14 bolt shafts do neck down but they are almost inexplicably strong. They are really tough to break with any tire size that doesn't start with 5 or 6 unless you have things REALLY bound up.
The 14 bolt ring and pinion setup is better than everything else in the light duty truck applications.
Here is a relatively recent thread discussing the same, Chris Overacker is local to us and those shafts were here at one point (the candy cane ones, they must have had ridiculous amounts of stress on them, we have broken many D60 shafts, knuckles, etc but 14 bolt shafts are the the old stand by that never gets broken).
I've never measured a 14 bolt shaft that was 1.625" at the splines and they are listed as 1.50" but some of the ones that I have measured go a little better than 1.50" and they are 30 spline as opposed to Dana's 35 spline that also claim to be 1.50". I haven't measured any of them that hit that number, close but no cigar. I also know someone that did some Rockwell testing and the 14 bolt shafts were slightly harder all the way through than the Dana shafts.
Gus
and the 14ff gov loc is the best for strength of all the gov boms. but can blow up yes.
There pretty close in strength then. Id run either one in a mud slinger...
The 70 has bigger axle tubes and can be geared deeper (though with it's already undersized pinion that can be problematic). The 14 bolt is better in basically every other way but the 35 spline D70's aren't far behind strength wise, they still hold up pretty good in general.
The big reasons to use a 14 bolt are that they bolt right into Chevy trucks, they are super easy to setup gears, they have cheap lockers, you don't have to spend lots of time/money figuring out which version of the D70 you have, you'll never break it, etc.
14 bolt FF shafts have a major spline diameter of 1.54" (30 spline). Dana 70s are 1.50" (35 spline). Both shafts neck down and almost always break by the middle of the shaft.
oh I agree, I run the 14 myself for all those exact reasons.
63chevyll
1/2 ton status
The axle tubes on 70's are so strong.
I know of 2 axle broken on 70s, but both were from some serious abuse
I know of 2 axle broken on 70s, but both were from some serious abuse
