I am going to pick up an Eaton posi diff. for my 8.8 build. 31 spline and 28 spline diff's cost exactly the same. I have 3 courses of action from here:

1- I can get the 28 spline eaton and use it with my stock axles and sometime in the future, upgrade them to some hardened 28 spline axles.

2- I can use the stock 8.8 trac-loc posi with my stock axles and then buy the 31 spline and buy some nice axles later on (not enough money right now to do this option).

My main question is, will the 28 spline setup handle what I can throw at it (hoping to be at 480-500 rwtq) when my car is at it's peak. I plan to launch on ET streets as well. If the 28 spline axles will handle that amount of power I will just go for option 1. If not, I will put the rear together with the stock 8.8 diff and my stock axles and upgrade to the 31 spline later. I just don't want to waste any money in between. Any input or experience would be great.

Thanks!

 

ttt

 

Well keeping the axles 28 spline stockers is really no better than the 10bolt. I know people have broken axles in the 10 bolt, granted more behind an m6 than an a4m but still thats alot of torque multiplication and traction on them.

The spline size is not only bigger, but the actual axle diameter is I believe.

 

Well I would eventually go to a hardened moser 28 spline axle but that would be in the future... I just want to know if a 28 spline axle is strong enough to support 500 rwtq.

 

I dont believe they are, but I guess all you can do is try it!