stupid question abotu 28 spline axles

beanplant said:

Okay, I'm wondering how strong these stock 28 spline axles are. How much power can they handle? Is it possible to break the axles alone? Or if they break, will it mess up everything (differential and such)?

Thanks!

-Shaun

Click to expand...

they will handle about 450hp depending on whether or not you are running slicks, and how old htey are, and if they show signs of twisting.

it is possible to break just the axle, in fact usually the axle breaks just outside the point where it enters the side gear, or just inside the point where the bearing retainer holds the bearing in place.

there have been occasions where debris from a broken axle has broken the diff and gears, but usually those were in race conditions, and those diffs were either a limited slip diff or a detroit locker, or something where if an axle broke, power would still be transmitted to one wheel.

I broke one in the middle. I was running slicks and little over 300hp with a 4.11 gear. Don't forget that ratio has a huge effect on how much torque is put on the axle. A 3.00 gears puts 25% less torque on the axle than a 4.11. Do your axles taper in the middle? Some of the earlier, mine were 64 falcon axles, are smaller in the middle. I also had a mII that the axles kept the same diameter from end to end and never broke with slicks, 4.62 gear, 550hp running mid sixes. It blew the caps off instead. The only reason it lasted is because of the weight of the car, another variable in the equation. It is a tough call to say how much it takes to break one. You have to figure traction, ratio, weight, shock to the drivetrain, axle hop, engine torque...... If any of these change, so does the ability of the axles to live. I don't see anything in your sig to suggest you need more than 28 spline though. I think Moser has a chart telling how to figure what size axles you need.

The ability of an axle to keep in one straight peice is not so much about power as it is about launch traction.

This little calculator should dispell any questions:
http://www.moserengineering.com/moser_interior/axletech.htm

I will echo the idea that it depends on axle design.

There are common 28 spline axles that are straight and retain their diameter over their length. There are common 31 spline axles that are thick at the splines, but actually neck down and become narrow over a large portion of their length. I have seen racing books suggest that the 28 spline straight axles are stronger than the 31 spline taper axles. Most car 31 splines are tapered.
Good luck
Dave

you would have to change the side gears in the differential. that means you would have to take the diff apart.

I think the step to 31 comes with slicks?

I just blew up my 8", and it happende cause me pinion inner (needle) bearings loop in the case broke. The pieces wen´t to gears and jammed them, causin my rear u-joint to fail ,and drive shaft was twisted also... Also lost both silencers ,but my 28-spline axles were just fine...