Axles 28 vs 31 vs 35 Spline

[Mustangcwo]

There has been a lot of discussion about axles on this website. Here is a good formula to figure out if your axles are good enough or if your on borrowed time. Now any axle can fail at any time due to casting defects, but here are the ratings and formulas:

TORQUE RATINGS
28 Spline – 4800 ft-lb (per axle)
31 Spline – 7000 ft-lb (per axle)
35 Spline – 9600 ft-lb (per axle)

FORMULA FOR AXLE TORQUE
(Max torque of your car (ft-lb) x (gearbox first gear ratio) x (diff ratio) x 90% efficiency.
Each axle should be able to handle all of the maximum torque your car can produce. This will create a 200% safety factor.
Example: A car has 600 ft-lb of torque, Turbo 350 transmission (2.52 ratio 1st gear) and a
9" diff (4.11 ratio gears)
Calcuated as: (600) x (2.52) x (4.11) x 90% = 5592 ft-lb
Therefore it is recommended that you use a 31 Spline axle which has a Torque
capacity of 7000 ft-lb

My Stang
TQ: 400
1st gear TR3550: 3.27
Gears: 3.73
(400)(3.27)(3.73)(.90)=4391
28 Spline should be good for me!!!

 

[ears]

hhhhhhhhhhhmmmmmmmmmmmm,,,,,,,,,,,,,,,,,, good info!!!

ya know sometimes i wonder where yall come up with this info!!

 

[atlblue98gt]

so i should need 31. since ive already broke a 28 spline superior axle.

 

[sdsubzero4]

What's in a stock axel?

With the calculation I'm at 4100.

 

[orange395w]

You are forgetting that it also depends on what the axles are made out of. Stock 28 splines and moser 28 splines are 2 different animals.

 

[atlblue98gt]

what does stock 28s hold vs superior 28s vs moser 28s? or any other good name brand.

 

[sdsubzero4]

You are forgetting that it also depends on what the axles are made out of. Stock 28 splines and moser 28 splines are 2 different animals.

That is very true.

 

[northerncountry]

well I know in the offroading world many rangers break 28 spline axles, do to the loss then sudden gain of traction. The same would be true on the track( tire shake ) then traction puts more stress on the axle. The axle wants to twist to take to sudden traction and then POP down an axle. i would go with 31 spline chromolly and call it good. if you break that then you should look for a custom housing and a built rearend.

 

[Mustangcwo]

You are forgetting that it also depends on what the axles are made out of. Stock 28 splines and moser 28 splines are 2 different animals.

Yes, if you purchase forged axles will you have a higher torque rating. The answer is to know the torque rating of your axle and then calculate what you are putting to the ground. I'm not researching every aftermarket axle known to man...especailly a set of Metro Sexual Moser axles.