Is a TR6 rear wheel hub the same as that used on the Stag?

[sujitroy]

Sujit

[DJT]

RB list TKC897 for Stag, TR6, TR4 IRS, TR5, 2000, 2500 & 2.5PI

[Motorsport Micky]

As shown above it's the same and shared with the big saloons. It's useful the TRs are often driven like Jehu (ie furiously) it accelerates the wear and flags up the failures of them in use. As shown on my recent posting with samples from the TR Register forum (free to access for all) you'll find plenty of evidence of them splitting, or stub axles snapping etc, etc.
Most of these hubs are dying now, the only safe hub is a brand new one, with a new stub axle, preferably uprated. Any attempt to recondition existing hubs stands a good chance of exacerbating any fatigue fractures lying hidden within and found out by you by driving to destruction...on the motorway/freeway, ...in traffic,... at whatever speed it wants to let go at.
When accredited NDT (Non Destructive Testing) engineers consider them impossible to crack test and pass as safe, it's time to consider other ways of maintaining a safe car.

Micky

[MandM]

Can you give some links because I can't seam to find them?

[Motorsport Micky]

Can you give some links because I can't seam to find them?

The TR Register search thread is a bit clunky just try using Google and input "TR Register Forum Rear Hub" and it will bring up posts which cover TR4a/5/6 all the IRS cars which use the Innsbruk system rear trailing arms/hubs etc like the Stag. You should find enough info there to make you feel disquieted !

Try this. Because it's in thread form as it was posted you'll often find posts that don't cover rear hubs or cracks included in it and I just scan (with eyes !) and select which posts I think are pertinent.

https://www.google.co.uk/search?q=TR...h=678&dpr=1.15


Micky

[new to this]

As shown above it's the same and shared with the big saloons. It's useful the TRs are often driven like Jehu (ie furiously) it accelerates the wear and flags up the failures of them in use. As shown on my recent posting with samples from the TR Register forum (free to access for all) you'll find plenty of evidence of them splitting, or stub axles snapping etc, etc.
Most of these hubs are dying now, the only safe hub is a brand new one, with a new stub axle, preferably uprated. Any attempt to recondition existing hubs stands a good chance of exacerbating any fatigue fractures lying hidden within and found out by you by driving to destruction...on the motorway/freeway, ...in traffic,... at whatever speed it wants to let go at.
When accredited NDT (Non Destructive Testing) engineers consider them impossible to crack test and pass as safe, it's time to consider other ways of maintaining a safe car.

Micky

My brother bought recon rear hubs,not that long ago out of Warranty now,and one broke,the keyway on the yoke broke,then the locknut came undone,he wae lucky the wheel didnt come off,he was driving the car at the time

[richardthestag]

Are you talking about the hub / bearing carrier or the stub shaft breaking Motorsport Mickey?

I thought the issue of the stub shaft breaking was quite well documented as being largely down to the hub and bearing carrier being incorrectly supported when changing the bearings.

I would be surprised if a machine shop could not detect run out or cracks in a stub shaft

[mole42]

My brother bought recon rear hubs,not that long ago out of Warranty now,and one broke,the keyway on the yoke broke,then the locknut came undone,he wae lucky the wheel didnt come off,he was driving the car at the time

Mine are recon hubs, one failed by mangling the bearing. I suspect the pre-load had been set a bit too high, they were quality bearings.

[new to this]

Mine are recon hubs, one failed by mangling the bearing. I suspect the pre-load had been set a bit too high, they were quality bearings.

I suspect theres a batch of these recon hubs, that have not been repaired / setup correctly that all the suppliers buy from

[mole42]

I suspect theres a batch of these recon hubs, that have not been repaired / setup correctly that all the suppliers buy from

The supplier, well-known in the world of big Triumphs, told me he'd rebuilt the hub himself. I have been able to determine the make of bearing that failed, it was a good German one, but the remains are too mangled to discover why it failed.

[MandM]

Had look on the "TR Register Forum Rear Hub" it seems that a lot of TR members have had trouble with rear bearing play, mentioned by MOT tester, should be 0.002 to 0.005 in which is more movement than you think at a dia on 14 inch road wheel, seems the TR register shop had supplied some hubs with 0.010" movement . Also saw the same couple of hub failures that pop up here again and again. it also seem that lots of TR members suffer with a twitch. Moss seem to get a good report for hubs, and in balance there is also 3 posts that I found where people have had problems with the new driveshafts etc , which have been replaced. It was also noted that we drive our car like "Nambys".

[Motorsport Micky]

Are you talking about the hub / bearing carrier or the stub shaft breaking Motorsport Mickey?

I thought the issue of the stub shaft breaking was quite well documented as being largely down to the hub and bearing carrier being incorrectly supported when changing the bearings.

I would be surprised if a machine shop could not detect run out or cracks in a stub shaft

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.
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Be surprised...Both.

The hubs are often abused when the bearings are replaced, 20 ton plus presses and an arc torch to warm the up are typical splitting regimes used. The worst being they are often cracked inside where crack testing cannot get to them. Check out the postings I've made previously where I've shown broken hubs and a broken stub axle, these are hidden cracks deep inside units where if you can't get to the surface you can't test it.

I made this post recently covering these failures on TR models with the Innsbruk suspension.

.....Because TRs are driven by more aggressive drivers (in the main) they are a useful "canary in the mineshaft" for items where components are fitted which share the same design amongst the Triumph Independent rear suspension cars, TR4a/5/6 and the large Triumph saloons.
We have numerous postings on the TR Register Forum of rear hubs or stub axles failing over the time and with a noteable increase in these over the last 5 or 6 years.
I've just done a search under Cracks covered in their Forum (it's free to all, no membership required, try it yourself) it covers all different cracks on the cars and I selected a number of postings amongst the pages listed there relating to rear hub and stub axle which are...

...Regarding your squeak, I wouldn't drive it until you get to the bottom of the cause, my 6 had an annoying squeak from the rear audible at low speeds, when I took it to Enginuity for them to have a look at, the cause was as per Mick's photo, my hub had cracked 3/4 of the way round the flange, so the wheel was about to part company with the car. When I had the car rebuilt I went for these http://www.vessey-classic-car-servic...m#.XzEOLC2ZMwc not cheap and they do come with their own issues but at least I know that all the wheels should stay on the car.

...get new hubs and axles and if you can't afford them park the car until you can. It may not just be you who suffers but other road users. Refurbished are just old high milage ones cleaned up and could break before you get out your driveway. The L/H stub axle broke just under the edge of the outer bearing where it couldn't be seen. It felt like a flat tyre, slowed down to about 80kph and there was a loud bang,the car (TR4a) went sideways and rolled 1 and a half times, lucky I had a rollbar or I would not be writing this.
Spent 7 weeks in hospital and now have two hands that are not a lot of use any more and a car that is going to take some time to repair. My brother has purchased a TR6 which he immediately pulled the hubs off and found 1 hub flange with the boss broken off like in the photo and the stub axle cracked and ready to part company on the right sides its off the road now until new hubs can be obtained. I have already purchased new C/V joint driveshafts and hubs from Rimmers which are waiting for my hands to start working.

And 3 posts from RogerH

*...Hi Clem,
if you are going to rebuild a unit then seriously consider a new shaft item 42 Shaft
This is one of two things that can snap and you lose the wheel. The old shaft can not be positively crack tested.
It goes from good to broken in very short order.
some of these high strength steel alloys do not help the NDE (NDT) inspector as the period from star of cracking to failure can be very short.
Also many of these steels allow micro cracking (un-inspectable) to exist for long periods before going bang.
Aircraft parts that use these materials are usually 'lifed'. I think our original hubs are at the end of their life.

*...Hi Stuart,
due to the nature of the steel and its heat treatment crack testing will do no good.
If there is a crack then you may find it. But. you will not find a crack that has not start yet or is very very small.
Similar steel on aircraft is often life'd as once the steel structure starts to 'go' it will be rapid.

*...The rear hubs are nigh on impossible to detect prior to failure.

These last three posts * are from Roger whose previous 40 years was spent Aircraft NDT (Non Destructive Testing) in BEA (remember them ) and then it's various iterations working upon many different aircraft of different airlines where he would examine and catalogue structures, and all the other intricate bits of the "Big bird in the sky" which takes us on holiday.

When Roger makes such comments... when he's not confident that a crack test on his hubs would pick up a crack in a 50 year old component and he replaces his hubs with new including new stub axles...I take it seriously.

Our own cars, our own decisions.



The last 3 comments are made by Roger an ex specialist NDT engineer whose spent a lifetime in the aeronautical testing arena chasing and testing for cracks in plane structures...he da man !

Micky

[MikeParker]

Speaking as a "Namby", I have still had a front axle stub shear and a rear axle drive shaft shear. That is in 100K miles. I think that is seriously worrying. I have replaced both front axle shafts, but am still pondering what I should do about rear axles and hubs.

The front axle stubs seem to have two design flaws. One is the necking in the taper that fits into the vertical link. That is where they seem to shear. The second is the taper angle which is shallower that that of the vertical link. This allows the outer part of the taper to move in the vertical link causing the stress fracture in the necked part. You can modify the taper to fit, but the only available spare still has the necking.

You can buy front axle shafts that fix these problems (eg. from CDD with no necking) , but they come complete with new hubs and at great expense. Similarly with rear axle shafts and hubs. You can get uprated versions of those, but again at high cost. Theses uprated parts also use non-standard bearings etc. The danger is that our cars end up with a range of different axles, hubs, driveshafts using non-standard bearings and other parts. This will cause real problems getting spares 10 years down the line. Manufacturers will only make parts where there are the numbers are there to make it worthwhile. If we all have different parts fitted, the numbers may not be there. The high prices will discourage many owners from upgrading, leading to a lot of dangerous cars.

I think the answer is to produce uprated versions of just the parts that break. That is a relatively small number of parts. Is it just axle-shafts and hubs?. Those could be replaced at relatively little cost which would encourage more owners to make the upgrade. Those higher numbers will also help keep the prices down and the supply of spares flowing over time. Perhaps if a number of us club together we could commission a batch? If these parts are in common with TRs then surely the pool of interested owners grows further?

Mike

[richardthestag]

sounds like a job for SOCTFL and chicken licken

[MandM]

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