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Rear hub failures

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OK so for those who saw the other thread, the rear axle assembly is at the shop. The guy is measuring for CV joints, and working on a custom carrier for a bolt on replacement.

I'm trying to explain the failure modes of the rear hubs, but would do better with pictures. Anyone have any of an IRS rear hub that broke?

TIA, Alan
 
Not sure. My guess is that the bearings gave out and froze on the stub axle and the lateral forces snapped it off.
 
What make cv joints and axles is he looking at?. there are some that never held up very well. you might need to steer him in the heavy duty direction.
 
I told him to spec it for a real 300hp at the crank. If that's not strong enough then I don't know what will be. It's supposed to be a bolt on replacement, and he's running the #s for all 3 common rear axle ratios.

The guy does CV joints for a living. I'm not going to tell him what to use when I'm not an expert on the differences. That's why I'm paying him - or at least I will be when I approve a design...
/ubbthreads/images/graemlins/cheers.gif
 
This might help him determine the issues at hand. After looking at the broken TR6 hub it reminded me of the pictures that I saw of the Tr4 hub that broke during racing. The similarities are compelling.


As I am sure you know this is what I pulled from the website.

“The failure started on the inside of the hub flange (where the outer bearing fits) once this had broken the stub axle quickly failed taking the brake drum with it. Both cracks seem to have propagated from the keyway slot for the woodruff key. No drive and no brakes!!! I believe the cosworth style hubs are a lot of money but well spent as a similar failure at high speed or on a fast wooded corner would have probably killed me

The only failures I have heard of in non-competition situations have been due to poor assembly or dismantling prior to rebuild due to lack of correct 25 tonne press , heating of flange to facilitate removal (screws with the stub axle hardening) and/or dirty assembly.”

Best of luck in the development and I will buy a set when things get finalized. Are you still talking to CV joints of Ocala?

bugger2.jpg


Mvc-646f.jpg
 
I know the TR4 site, but it's a solid axle so I figured the design isn't comparable.

I'm still dealing with the chap in Ocala - He's been looking at specs for CV joints. I spoke to him this morning, and he'd picked out a 4" one - I sent him the measurements for the cylinder through the swingarm that this has to pass through at lunchtime (had to call the mechanic to get them, and was told ID is 3.5" so it won't work - bummer).

He's aware of the competition pricing - I told him it needs to come in under $1500 a set for it to be competitive, and he seems to think that's do-able, and it may be less depending on the amount of final work.

I also requested that it have more modern bearings that can be replaced without jumping through hoops, keep both wheel and diff mounts hub centric, and be a bolt in fit with zero modifications required. Oh and it will be splined, not keyed...

I'm hoping that given the small ID he can find something that will work at the price point. Hopefully I'll hear back again with the final design blueprints in the next few days.
 
Alan, if you look closely at crj7driver post the first pic is an IRS the second is a solid axle. Two different cars.
 
And if you read my second post you'll see I posted the link to the first picture...
 
Sorry Allan.
When I tried that link all I got was a list of topics, no pictures. I will try it again to see whats what.
 
You need to cut and paste the whole thing - the ',' stops a direct link.
 
Thanks Alan just figured it out. Sometimes I'm not too good with the computer! /ubbthreads/images/graemlins/confused.gif
 
Alan, In the Moss (Europe) ad for their hub assembly they mention one of their problems was finding a axle/joint assembly that had enough plunge to accommodate the TR6 axle in and out movement, this could be something your guy needs to be made aware of, although judging from your previous reply he is probably already on top of it?
 
Not that this is a very helpful contribution to the subject :smile: ... but that doesn't look like a TR6 rear arch to me (the white IRS with the busted hub posted above). Obviously it's the same IRS setup. Is it a 4A/250? - doesn't even look like one of those to me (from memory). Just wondering. Pete
 
[ QUOTE ]
Not that this is a very helpful contribution to the subject :smile: ... but that doesn't look like a TR6 rear arch to me (the white IRS with the busted hub posted above). Obviously it's the same IRS setup....

[/ QUOTE ]I believe that image is of a 2000/2500/2.5 Triumph saloon, which does have essentially the same IRS setup!
 
It's from a 2.5PI Saloon.
If you read the posts on the forum - the link in post 2 in this thread - you'll get the skinny on what happened, and where the car is from.
 
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