Comparing rear axels

[slim616]

Heres a few pics of all the different size rear axels together.
from left to right its a d60, 8.8, d44, d35.
Notice that there's not to much of a difference in size from the 8.8 and d60. (edit 30 spline d60 shaft)

[zj95maxx]

30v60

[ajmorell]

I know the info is out there, but you should've mic'd or put a set of calipers on the splined and unsplined sections of each shaft to get a better comparison.

[Nonstop]

60 vs. 30

[slim616]

did a quick cut an paste, but you can find all the info on google really quick. I just posted a picture because its kind of fun just to see them all together at once.

BillVIsta did a comparason: STRENGTH COMPARISON OF COMMON O.E. AUTOMOTIVE & RACING SPLINES and used a 12 bolt Chevy as a reference.

GM 12 Bolt Diameter 1.2917 0.0%


28 spline Older Jeep/Dana 1.1960 -21.9%
30 spline Dana 44 1.2793 -3.0%
35 spline Dana 60 1.4876 57.0%

28 spline Ford 9", & Ford 8.8" 1.2083 -19.3%
31 spline Ford 9" 1.3333 10.7%
33 spline Ford 9" 1.4167 34.4%
35 Mark Williams 35 Spline 1.5000 61.2%
40 MW 9" & 40 spline D60 1.7083 143.2%

So what this is saying is:
The 35 spline D60 is 57% stronger than the 12 bolt
The 8.8 is 19.3% weaker than the 12 bolt similar to the 28 spline jeep.
the 30 spline D44 is 3% weaker than the 12 bolt
the 28 spline jeep is 21.9% weaker than the 12 bolt

[ATL ZJ]

So what this is saying is:
The 35 spline D60 is 57% stronger than the 12 bolt
The 8.8 is 19.3% weaker than the 12 bolt similar to the 28 spline jeep.
the 30 spline D44 is 3% weaker than the 12 bolt
the 28 spline jeep is 21.9% weaker than the 12 bolt

That's assuming the shafts are all the same material, right? of course even stock full float shafts will have the benefit of being made of different material, which make them stronger than their semifloat counterparts of the same diameter. Also, does a 1% increase in diameter result in a 1% increase in shaft strength? This would mean that a 35 spline dana 60 shaft is only 78.9% stronger than a 28 spline dana 35 shaft, assuming they are made of the same material.

[EMTimZJ]

That's assuming the shafts are all the same material, right? of course even stock full float shafts will have the benefit of being made of different material, which make them stronger than their semifloat counterparts of the same diameter. Also, does a 1% increase in diameter result in a 1% increase in shaft strength? This would mean that a 35 spline dana 60 shaft is only 78.9% stronger than a 28 spline dana 35 shaft, assuming they are made of the same material.

No a 1% increase in diameter = a 1% ^4 increase in shaft strength.

Take a 1.00" diameter axle for example; a 1% increase in shaft size is: 1.00*1.01=1.01"

Strength increase = original strength*(1.01^4)
Increasing the diameter increases the strength greatly.

How are you getting the 78.9% increase? Using the 1.2917" and 1.5" of the 12bolt and D60 diameters I get an increase in diameter of 16.1%. Also the increase in strength (using your scenario of same material/heat treat) is 81.85% of a 35 spline D60 over the listed diameter for the 12 bolt.

HTH

[ATL ZJ]

Combination of the absolute value of the differences in d35 and 35spl 60 from the benchmark of 12b. According to slim's numbers, that would mean 21.9 + 57 = 78.9. I had a feeling it was not quite that simple.

Good info Tim.