31 spline axle upgrade

[Ace23]

I am upgrading my 8.8 rear end. Can anyone give me a recommedation on where to source the 31 spline axles? The rear will be getting 4.10 gears, new bearings, seals and a Eaton tru trac diff.
Thanks in advance.

[vatdevil]

Here ya go:

31 Spline Halfshaft Upgrade

I eventually installed 4340 center bars from DSS and the outer joints from the Mustang assemblies. Most important part to prevent breakage are the solid diff mounts. Wheel hop is bad!

[LMH]

X2 for DSS. They made my 31 spline set up on my Hurricane. I provided the CV joints, they did the center shaft and assembly.
Larry

[Ace23]

I will give DSS a call. Thanks

[Ace23]

I spoke to an axle vendor today and they raised a good question. When I told them I wanted to do a 31 spline upgrade they came back with on your superformance "your axles on the diff side will be 31 but your wheel side will still be 26 spline".....so it will still have a weak side. Any comment besides that is one honest salesman or a misinformed one.

[vatdevil]

the spine engagement length is much longer on hub side, which negates some of the difference in strength. Did the salesmen try to upsell you to the expensive outer joints?

[Ace23]

Originally Posted by vatdevil

the spine engagement length is much longer on hub side, which negates some of the difference in strength. Did the salesmen try to upsell you to the expensive outer joints?

No, he told me it was a waste of money if it was a street car and I was not going to be dropping the clutch and trying to launch the car. I figured going with drag radials and 4:10's would create additional traction/stress and it would be a good precaution.

[LMH]

Yes, that's true. It's also the way Ford did it on the 03/04 Mustang Cobra in which the CV joints and differential were used from the factory. I've never seen an outer CV joint break but I have seen a couple inner joints break.
The next weak point is the production differential cover. The production cover is just not strong at all.
Larry

[vatdevil]

Originally Posted by Ace23

No, he told me it was a waste of money if it was a street car and I was not going to be dropping the clutch and trying to launch the car. I figured going with drag radials and 4:10's would create additional traction/stress and it would be a good precaution.

Most important improvement is replacing the stock diff mount bushings with solid. Wheel hop is real hard on halfshafts

[Ace23]

Originally Posted by LMH

Yes, that's true. It's also the way Ford did it on the 03/04 Mustang Cobra in which the CV joints and differential were used from the factory. I've never seen an outer CV joint break but I have seen a couple inner joints break.
The next weak point is the production differential cover. The production cover is just not strong at all.
Larry

Originally Posted by vatdevil

Most important improvement is replacing the stock diff mount bushings with solid. Wheel hop is real hard on halfshafts

So you guys are advocating just swapping the gear only and going with the solid diff mount bushings from someone like Craig's Cobra?

Also is our 8.8 diff the identical diff that was used in the 03-04 cobras? If so I know where a brand new 03-04 cobra diff is......that would give me the 31 spline setup and all I would need to do is change the gears. I could sell my current diff.

[LMH]

Best one of the SPF guys answer that exactly. I know they used Ford 8.8" differentials but I think there was a switch to a different diff at some chassis number. The 8.8" unit is the same as other cars use, my Hurricane included. I wanted an aluminum case for weight and the 31 spline axles for strength. Solid mounts is the only way to go IMO but the weak point is the cover and should be replaced with a better one. That goes for the cast iron diff as well.
Larry