Id go 31 if i were to do it over again i also have to say that i am a proponent of avoiding breaking parts. Generally 28 spline have an oval hole on the outboard ends while 31 have two round holes.
Strange S Series Steel Spool For Ford 9 With 28 Spline Axles
28 vs 31 spline axles. Ironically i have aftermarket 28 spline axles in my car. 31 splines are definitely stronger. 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. Aftermarket 28 spline axles are going to be much stronger obviously but at that point you might as well go 31 spline. 31 spline axles also tend to be larger in diameter to accommodate the increased amount of splines. I got a carrier from a cobra because they are 31 spline with carbon clutches.
Each axle should be able to handle all of the maximum torque your car can produce. A dollar to a donut theyre 28. 28 spline vs 31 spline axles the obvious differences in 28 and 31 spline axles will be the number of splines. This will create a 200 safety factor. The axles themself and the diff carrier. They both have the center drilled hole for lathe work.
Theres really only 2 parts needed to make the change. When you count the number of teeth splines on each axle you can find out which option you have. Most 28 splines are tapered and most 31 splines are not. I went with moser for the axles. Strange 28 30 31 spline alloy axles forged from modified 1550 premium steel majority of machining performed before heat treat to provide consistent hardness induction hardened to rc 58 62 to increase torsional strength while remaining ductile finish machined after heat treat to ensure accuracy choice of 28 up to 31 spline. Someone else finds a exception.
I believe the 05 musyang gt came with a 31 spline carrier but i think there axles lenght are differant. And ford came out with them in the early 60s when the 406 and 427 equipped big full sized fords had trouble and were breaking the 28 spline ones. Every time someone comes up with a hard and fast rule.
Gallery of 28 Vs 31 Spline Axles
