Hello,

Has anybody ever heard of a rear stub axle failure? Have pictures?

I have a Turbo V8 converted American XR4Ti that I have been drag racing and last year I broke an OEM 2wd Cossie axle. I replaced the axles with upgraded unit made out of 300M, that should no longer be an issue. I already have an 8.8 diff in the back, so that is also not an issue. But I am worried about the 27 spline stub axle that goes through the rear hub. I had mine X-ray analysed to determine the material and they are just a 1040/1050 steel. Not a Cr-Mo. Based on my calculations if I were to put some drag radials in the back, they won't handle it. Yet, I can't find a single example of a broken one on the web.

I know there are a few low 10 sec to 9 sec Cossie's on Youtube. What do they run? Are they all converted to solid axles?

Video of my practice launch.


I have since gone to the track and went 7.06 @ 105.5mph in the 1/8th. That should be go for a mid to high 10's in the 1/4.

Thanks in advance,
Tim
XR4X4Ti

 

Never heard of them braking and wenny's car runs very low drag times, I have seen him snap a front shaft which spun him in to the wall.

 

Im sure it was a rear shaft that snapped on wennys escort.

 

Really? would that make it spin / turn as violently as it did?...I just assumed it was front.

 

never heard of a failure either

 

I’m sure rod broke one back in the day at 10 of the best. But you would have to ask mark for sure

 

Was Rod was still running std stubs in his car with plenty of power and torque ?

I have never heard of a failure if anything it would twist the splines.
or if the stub was Torqued up too high it could put undue pressure thread area which could shear off.

Drag racing puts so much strain on components I would always worry about the std prop to diff bolts.

 

You need to be careful with materials to
If they are to hard they also will give up

Think cr mo is a European en
But it is a touch harder as I am looking at materials
At the mo to make some centre lock stub axles
To go with the bbs e50,s I have made

 

Yes, you are correct, you can't go to hard with the material. Something between 38-45 Rc is usually about good for an axle. I have not tried to measure the hardness of the Cossie stubs since they are induction hardened only in the spline area and it would be difficult.

But, going from a 1040 to a 4340 even at the same hardness can net you a 50-75% increase in strength. I purchased some 928 stubs for the heck of it and had them X-rayed, they ARE a Cr-Mo steel.

I was going down a path of having some custom 30 spline stubs made, but the machine shop jacked up the price right when I was going to place the order. So, I am trying to decide if I should just not worry about it, at least this season. I wanted to try some drag radials this year, but I may just leave the stubs and skip that.

Tim