Competition spec. Sprint half shaft

[paulsprint]

After suffering from half shaft flex at the last track day which wrecked the rear oil seal and brake shoes.
I am a going to get some half shafts made in S155 aviation spec material by Tranx. They will use the same bearings and hubs etc. but the main shaft will be thicker around, 30mm dia.
Is anyone interested in a set? They will work out at out £160 a pair.
Please let me know as the more I can get made the better.

[DF]

Very cheap for a comp half shaft set

[Mad Mart]

There are a few of us that regularly attend track days in our Dollys. I found after the first one I did, I had the same problem. Someone on here said replace the inner axle seals with the front gearbox seals (part no. 141756), I did (and others have). 4-5 years of track days later, they are still holding up.

[DF]

I suppose only really good if your running slicks which most of us dont

[Carl]

pm sent

[paulsprint]

I already have done the oil seal mod, this time I appears it may be the big outer seal. Drum was full of oil and grease. The shaft had been flexing that much that the brake drum had be rubbing on the back plate , only at the bottem though. The rear wheal bearings are shimmed up correctly and the oil seals where replaced not long back.
This is a problem I have not had at other tracks, but Cadwell Park has four long very fast right hand bends which are taken flat out in third. I was using my old Faulken ZE512 Tyres with very little tread left, not slicks or even track day tyres, just old road tyres. Now the car is back to running on the road the oil seal is fine. Looking at a standard shaft they are tapered down to 20mm halfway down. I mentioned the problem to my brother (works for Tranx) he is looking into making half shafts for the TR4 for some Dutch racing team out of S155 aviation spec material. He said if I get enough interest he will be able to a run of sprint shafts as they are very similar to the tr4.

[wiggybum]

Do you have any idea about leadtimes? My axle is just about to be rebuilt and I'd be interested in a pair.

[tinweevil]

It was some considerable time ago I heard this so it may not be related to sprint but I was told you can fit a 2nd set of bearings half way down the axle tube to reduce halfshaft flex. Anyone know if there's any truth in this for our cars? Would it need a non waisted ST HS first. I guess it would then make axle flex worse but there's an ST fix for that too.

[SPRINTPARTS]

fit a 2nd set of bearings half way down the axle tube to reduce halfshaft flex

There is a Leyland Service Bulletin covering this mod. (I don't think it was only a Leyland Australia thing). From memory it stated that the mod was suggested for vehicles being driven hard or in competition use. They way things seemed to worked back in the '70's if you wanted to modify a car for racing but didn't wish to change the production build for road cars, then just write a service bulletin to cover what your wished to do. I don't know of any road cars that have ever had this mod done. It is fairly involved and requires modify axles and diff housing tubes.

Our race cars had this mod done 30+ years ago. Some of the rear axle assemblies that we use still use this setup and a couple now just use heavier (bigger diameter) duty axles which are modified from 6 cylinder Vandguard items.

Mark

[Hans ten Broeke]

By any change, are they gun drilled ??
We use in both cars the comp half shafts, and normal oil seal, not these leather ones, no reel problems, but these shafts are so extreme heavy.

Hans

[rich]

if you check out jigsaw racings site you'll find they sell uprated half shafts

rich

[paulsprint]

saw my brother today and it appears i got the wrong end of the stick (not unknown to happen) he will cost them up next week but i looks more like £160 each not a pair sorry!! . I will PM those of you who have expressed and interrest.

[DF]

As i said above very cheap for a set at 160
I know how much they cost as i had a set made for my dolomite axle before i binned it
It was the diff that let me down in the end.