Stub axle fails at track

[Randy]

:cry::cry:With only 4 laps under my belt on a beautiful sunny day at Thunder Hill, i was coming out of the last turn on to the main straight away, accelerated to 6000 rpm and shifted hard into 4th when the driver side stub axle sheared.:furious::furious::furious: Still have not gotten a whole track weekend without braking something.:sad:
In looking at the axle it has 26 splines which seems a little small. :stunned:The axle sheared right were the spline starts. Anyone else have this problem? I spoke with Ian and I think there is a confusion over what kind of stub axles are being use on post 100 CAVs.
Randy

 

[Randy V]

WoW!!!!

Glad to see that you're okay! At that speed, it could well have been catastrophic!

 

[Fran Hall RCR]

Randy,

do the splines look broached or roll formed....??

 

[Randy]

Fran, it looks broached, and yes I feel very lucky it did not get messy.
what size are you using?
Randy

 

[Fran Hall RCR]

Mine are made in house..

I spec mine to be roll formed...no material loss.

I use a GM C4 Corvette spline....

 

Randy,

Sorry to hear about your problem. I was running on Sunday and wanted to come by and say hi. Next thing I saw was that it was in the trailer. We had a bit of trouble as well with one of the cars we brought the (1991 Trans Am Mustang) so things got busy between my track time and trying to get that car fixed enough to get it into the trailer. Hope you get your problem solved and we see you out there again soon.

Don

 

[Malcolm]

It looks like a language issue here to me! Stub axles to me are on the wheel side of the upright but this sounds like you are describing a rear axle failure where the drive shaft goes into the axle via a CV joint with a spline drive to the wheel?

I have heard of front stub axles breaking but never a rear axle failing. Drive shafts and CV joints also fail every so often. But to fail at speed does seem odd. Normally these fail when you do a quick start. Breaking where the spline starts is a common break point on drive shafts. One cause was known to be not enough play in the drive shaft so that on bump it "bottomed out" and so blew the CV joints apart. A slightly shorter shaft sorted that one. Hope you find the cause for your failure.

 

[Jac Mac]

Given Randys description my take is the failure is in the rear hub assy outboard of CV/U.Joints. Pics would help, but if I am correct then its about the safest place in the rear driveline to have a failure as long as you stop immediately and dont try to get back to pits with one wheel drive. CAV appear to run brgs directly in upright, while RCR IIRC use Corvette Bearing/Hub Assy bolted to rear upright.