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View Full Version : some good dana 44 tech(baron check this out)


Squishy
05-16-2005, 10:01 PM
An axle is only as strong as its WEAKEST LINK (key thing to remember) and a "stock" f150 dana 44 has a weak link.

below are "stock" engineered breaking strengths, dana 44 and a dana 30 just for comparision factors. These are engineered strengths, not destructive testing data but will be fairly accurate since they were calculated using 1040 formulas and actual smallest diameter, not the spline diameter which is not the weak link in a "stock" 44 shaft. The 44 necked area (weak link) is not to be confused with the more radiused longer necked areas found on some of the old shafts and some dana 60's, the longer radiused necked shafts are a good design. The short steep necked areas on the 44's are apparently a designed in weak link, intended to break and they do that just fine (turds).

"stock" 1040 Dana 44 inner at the stress riser ("bad" neck down") breaking strength approx 3600 lbs-ft (probably a good bit weaker in reality, actual testing data would be nice) A spicer 760 has a breaking strength in the area of 5600 lbs-ft, anyone breaking a spicer joint in a 44 is breaking it simply because the clips come off and the cap makes contact with the ball joint (always weld your joints in). A 760 has a 'weak link" too while were on the subject. Even though the cross section is strong the bearings are weak and will crush before the joint will break. A better option I have found from trial and error is the exact fit part number xf297 joint. It is made by Dana corp and has a better bearing design, it is also stronger than the stock shafts and a very good, cheap upgrade.

"stock" 1040 dana 44 stub approx 3800 lbs-ft breaking strength

dana 30 1040 carbon steel approx 4200 lbs-ft (aint that a bitch). Actual destructive tests would show it to be slightly less at the splines, probably in the ball park of the 44 stub but still stronger than the shitty necked area on the 44 shaft.

Now we do a slight upgrade on the 44

aftermarket 1040 carbon steel inner dana 44 shaft without stress riser approx 6000 lbs-ft. destructive test again would probably show it to be slightly less at the splines, especially if they were cut. These would be shafts like a regular moeser (I would guess) or any aftermarket 1040 that is made without the necked down stress riser found on the stockers.

Wanna go bigtime with an upgrade?
You've eliminated the neck down with aftermarket 1040's and it aint enough? as the material improves the shaft strength will increase with it (obviously) but how much? 1050 approx 10% 4340 approx 30-40%. At this point the joints become the weak link and you need to think ctm or other.



on to the 8.8. Do the math and we see that the ford 8.8 has an estimated breaking strength of 6100lbs/ft. Compare to the dana 60 30 spline rear which has an approx breaking strength of 6000lbs/ft.

These formulas are not a set in stone kind of thing because I did not take into consideration deflection related to the axle's design and length which would be damn near impossible to calculate. We could discuss it further if you like but the simple facts are the 8.8 is strong, dana 44 is weak.


__________________________
1984 Bronco II, 302, NP435,NP208 Doubler, NP205,5.13 Dana 44/8.8 Fullwidth, Detroit, Coil Front, 36" Militarys
LOCKED AND LOADED!
Aint Lookin For Nothin But A Good Time, And It Dont Get No Better Than This!
IT'S A BUNCH OF TREE-HUGGING GIPPIE CRAP!

BeerBaron666
05-17-2005, 07:34 AM
quote:We could discuss it further if you like but the simple facts are the 8.8 is strong, dana 44 is weak.
Thats all good but they don't make a 8.8 for the front:D the ujoint thing I knew about and the last axle that broke(well the first of 2[xx(]that day) Ithink one if the caps was busted already cause I did the fullclip on them so the caps can't come off and yes they were kind of cheap joints but all I could get in time.

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Squishy
05-17-2005, 09:16 AM
run some 4340 shafts

__________________________
1984 Bronco II, 302, NP435,NP208 Doubler, NP205,5.13 Dana 44/8.8 Fullwidth, Detroit, Coil Front, 36" Militarys
LOCKED AND LOADED!
Aint Lookin For Nothin But A Good Time, And It Dont Get No Better Than This!
IT'S A BUNCH OF TREE-HUGGING GIPPIE CRAP!