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[MD]

Broken CV joint on driveshaft.

I have never had a breakage on my road cars but broke a fully reconditioned one on the race car. It was on the left hand side. The ball cage broke into a dozen pieces. This was the smaller 2 litre spec driveshaft. Since then I have spoken to a fellow racer who says he has broken one of the same type recently as well.

How common is the problem of breaking CV joints on the rear drive shafts?

[Mats]

No idea how often it happens, it happened to one of the cars in our series this year but that is really the only one I've heard about locally.

What kind of grease did you use when reconditioning yours? Was it an inner or outer joint? How low is the car (or what joint angles if you know)?

[MD]

Yeah hi Matts. The grease was selected by the reconditioning company that does this all the time. From the look of it when examined after the failure, it looked to be a fairly light grade but I am guessing really. There was certainly plenty of lubrication however.

In relation to the vehicle height, I would say that the rear drive shafts are running close to zero angle and the suspension movement is limited of course to perhaps 35mm. One could say that the low angle had some part to play in it until I realise that the other race car I mentioned that broke one also runs pretty much standard height with more CV angle so perhaps it's not an issue after all..

[Giuliettaevo2]

MD,

all the racers here in Holland use a special high temp grease for the inner joints. This because of the very high temperatures the joint can reach as a result of the heavy braking. especially if you have a brake-bias adjuster you will generate more heat and boil the grease in the joints.

looked it up on the dutch site and found out it is called Red Line CV-2 grease.

[MD]

Appreciate the feedback. Usually if the heat cooks the grease, you can tell from the changes to its character but this grease was like brand new when I examined it after the failure so I am confident that it is the correct lubrication.

The interesting point here now that I think of it is that the early Alfettas had shorter driveshafts compared to the later ones. To connect to the output shaft of the differential, they used a spacer which had an open cage set up. This provided some cooling between the brake rotor heat and the CV joint. For the later models, this idea was dropped and longer shafts used to do away with the joiner with apparently to no detriment simplifying the fixings and minimizing the number of joins in the drive system. I use the longer shafts.

...I am still at a loss to offer an explanation of why it really broke.

[Mats]

If the cage broke it sounds more mechanical then temp. Are you sure the shaft is the correct lenght? If you force the joint to run plunged in either extreme direction it will not take so much to kill it.

Some pics of the other shaft in installed position would be nice if it's possible.
Maybe the joint got a violent treatment at the company that repacked it?