Broken stub axle on a Crossle 45F

[snettleship]

I was racing at VIR with the VDCA vintage club the same weekend as the as the FF event Pro event. Great to see the spectrum of FFs from 1967 Lotus all the way up to my 1981 Crossle 45F.

In the Saturday feature race I suddenly got the "bag of neutrals" at the end of the backstretch and coasted in. After starting to take the rear cover off the Hewland, I noticed the left rear axle connection to the rear hub was askew. The stub axle was sheared in half where it inserted into the rear spindle. Also the end of the axle looked like it had some damage and some damage where the axle meets the flange (?) that has the sub axle. Sorry, I may not have the part names correct as I don't have the diagram in front of me at the moment.

I talked to my suspension expert at Apex Vintage and he wants to find out of this was metal fatigue or not. Another question I have is it possible that the rear track is a little short and the travel of the axle isn't what it should be. Maybe going over a curb the wrong way could have caused strain on the stub axle while rotating?

Or, maybe this is just a wear and tear part. Is this common on a later CF Crossle? Thanks

[Clyde]

Just a thought ; if the rear hub assembly was changed to a model 25 or 30 Crossle for whatever reason, then those stub axles were weak and were replaced in the model 35 and newer. You need to measure the broken parts as the later designes were thicker.

[stephen wilson]

I don't know about stub axles, but I've broken a CV joint on my RF78. I think it was due to a bumpy braking zone, which is transfers thru the axles on inboard brake cars, which I believe the Crossle is?

[Svensken]

The bearings in the rear upright have to be shimmed for a perfect fit. If the bearings were wearing out the play would increase and that could also put extra strain on the stub axle. Have the uprights rebuilt with new parts (as required) and you should be fine.

[Sweeper]

I've had this happen a couple of times. The companion flange sheered off right at the spline. Both times we could see the rust that indicated that the area around the spline had been cracked for a while. It has been decided that the transition from spline to the companion flange was not relieved enough, in fact it is pretty squared off no radius at all.

While setting bump steer on the rear. I measured the angles of the half shaft throughout the suspension travel and there where no binding spots. After a two failures, i've had good luck and it's a few years since it broke. I think it was a design failure or manufacturing issue.
I hope this helps

[snettleship]

Thanks for the info. Yes, this looks exactly like what I have. Since I purchased the car 2/2010 I don't know how old this part was. Talking to Neil Porter it seems like the metal in the half shaft is not the 'hardness' as the surrounding parts (e.g. spline). I have ordered a replacement companion flange and will take a close look at the other side to see if there are any cracks developing on that half shaft.

[Sweeper]

The other thing is it could be the super duper HP coming from my Quicksilver, just twisted it off... 200hp will do that.

[snettleship]

ya know what, my engine was built by Quicksilver also. Said there was only 10 hours on it when I got it. Claims were that it was dynoed at 109 hp but maybe they switched the '9' and '0' to keep it a secret. That would explain everything!

[Sweeper]

,

[snettleship]

Rob,

By the way as I read your entry again, you may know this car. It was previously owned by Peter Faill. I got it last year from the person he sold it to in Chicago.

[Sweeper]

Hi Scott,

Oh my, I remember this car. It has a terrible habit of being in the rear view mirror.. Kidding!!

Peter and I had some battles and we agreed before hand that if either one causes a wreck that we wouldn't get too emotional and run off in a tiff.

He is a good driver and I wish he had stayed in the CF. Now he's a dedicated tin topper, dual entry everywhere. He drives all the time...

Good luck racing!!
Sincerely, Rob