914 CV Joints

[Jonny Hart]

My 914 Tesla conversion will put around 300 HP through the driveshafts of the 914. The driveshafts are custom which means Tesla inner CVs and standard outer CVs.

On inspection, one of the outer CVs is worn and needs replacing. I had though they were the same as 911 but apparently not. A few questions then:

Where to people get replacement outer CV joints for 914s?

What are people using on a 914/6? Standard or uprated? What are my options?

Thanks.

[rhd racer]

Hi Jonny

I had exactly this problem with my hillclimb car so did a number of upgrades through the years, ending up with the largest CVs you can get (68/69 I think) 4 bolts / 2 roll pins. They are about 50% bigger than a standard 914 one. The most economical way was to buy axle sets from Pelican, sell the 911 driveshafts as they are too short for a 914, and have custom ones made. I am pretty sure all 911 stub axles fit through a 914 hub, you just need to match to the CVs you are using. For a while I used the 6 bolt SC ones, which sit in between the 914 / 911 ones on size, but these use smaller bolts than the early 911 ones.

Given you are going to have to get driveshafts made, I would get the largest stub axle / CV combo you can for the outers and the Tesla ones on the inners. The shafts I had made were rated to 500hp, and although some years ago were a surprisingly reasonable cost of c£300.

The engineering company I used was based in the West Midlands, and they do competition CVs too. I cannot recall their name, as they took over the work of an ex racer I knew, Bob Dyson, when he sadly died. Mike might be able to dig out the invoice for you.

I think your choices will be limited by the availability of the stub axles. I do have some engineering drawings somewhere of the shafts I had made, if you drop me a pm with your email address. I would steer well clear of embarking on what you are doing with standard 914 CVs - the cages holding the bearings will disintegrate after a few standing starts! Also make sure you use Schnorr washers to stop them undoing, or better still lock wire.

Hope that helps
Wayne

[swb100]

Morning Johnny, yes to all the above but the other consideration is if your car has or you want 4 or 5 studs as the splines are different. Cheers, Glynn

[rhd racer]

Yes of course, good shout Glynn.

Spoils Jonny, that all assumes a 5 stud rear....

Cheers

[jwhillracer]

Given you are going to have to get driveshafts made, I would get the largest stub axle / CV combo you can for the outers and the Tesla ones on the inners. The shafts I had made were rated to 500hp, and although some years ago were a surprisingly reasonable cost of c£300.

The engineering company I used was based in the West Midlands, and they do competition CVs too. I cannot recall their name, as they took over the work of an ex racer I knew, Bob Dyson, when he sadly died. Mike might be able to dig out the invoice for you.

Hi Jonny,

The guy you want is Ashley Brand, who took over my old pal Bob Dayson's business. He has all of Bob's old drawings and spec's and mad me a batch of gearbox flanges not long ago, improving on Bob's original design.

Brand Mechanical Engineering Co - 0121 327 6622

They make driveshafts and flanges for the 700bhp plus single seat Hillclimb cars, and while they probably can't promise that they will never break, they certainly take a lot of stick over a long time before they do!!

Cheers!
JW

[Jonny Hart]

Very helpful as always chaps. Thanks!