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CV-halfshafts WARNING!


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Noooooo not me! I’ll stick with Mr Standard Triumphs design albeit with new not recon hubs!

Mine were potentially 40+ years old and felt they were passed their sell by date.

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Noooooo not me! I’ll stick with Mr Standard Triumphs design albeit with new not recon hubs!

Mine were potentially 40+ years old and felt they were passed their sell by date.

The thing is engineering design moves on! Although mine lasted 44 years with only one U/J changed they are a pig to grease especially the outer U/J's which involves dis - connecting from the diff. drive flanges and brake drum. The grease that I used to put in the sliding splines seems to disappear very quickly, I don't know where? and it was the correct type as per GKN/ Hardy Spicer literature! Having gone to the C/V type design it is now plain to me that the original sliding spines are always locked up while in drive mode which is not what you want for the suspension on the rear to work correctly. But I have no experience of the coated spline type which I would always now go for if I had to use that type again!

Bruce.

 

Bruce.

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I do have CV axles and modern hubs for some years and would never look back to the original construction due to the inherent flaws of the key layout and the effect it may have on the durability, when things go wrong during assembly.

I'm well aware that a TR does not have the passive safety of a modern car.

I can encounter that fact with driving more carefully and defensively. But the fact to loose a rear wheel at any time is not acceptable for me personally.

 

Having said that I fully agree that it is also not acceptable, when you pay such a high amount for CV axles, that there is play between the half shaft splines and the inner cage of the CV joints, which results in clunks, when you do not release the clutch like mother's in law darling.

 

I tried with bonding them with a special Loctite kind of stuff (it wasn't from Loctite, but from ebay.uk and of course much cheaaper than the original Loctite) This bonder did not cure really and thus didn't help.

 

After that, I received another pair of half shafts from the dealer, which he had I think nickel plated in the splines, after he found out that the axle supplier rolled the splines smaller than he would have to, so to mate the female splines in the cage. This improved things, but did not cure it completely.

 

So the question is, before throwing things into the bin, has anyone tried to get the splines nickel plated to mate the female splines, with close to 0 play?

 

Cheers,

Patrick

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Hi Patrick,

Nickel plating a wear surface doesn't sound right to me.

Hard Chrome is the usual plating medium for wear surfaces and to build up to a tolerance.

 

Your concern regarding the original hub design is valid but you must consider that the failures are on hubs that are 30, 40, 50 years old.

The design, with the correct materials, is good - but should have a life on them; perhaps 20 or 25 years, then change for NEW hubs (not recon).

 

Roger

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Hi Patrick,

Nickel plating a wear surface doesn't sound right to me.

Hard Chrome is the usual plating medium for wear surfaces and to build up to a tolerance.

 

Your concern regarding the original hub design is valid but you must consider that the failures are on hubs that are 30, 40, 50 years old.

The design, with the correct materials, is good - but should have a life on them; perhaps 20 or 25 years, then change for NEW hubs (not recon).

 

Roger

Hi Roger!

 

There were failures on high mileage company car 2000 & 2.5 saloons even when these cars were production! GKN even tried to sell a CV type and revised wheel hub design to BL but it was the extra cost that killed that!

 

Bruce.

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So the question is, before throwing things into the bin, has anyone tried to get the splines nickel plated to mate the female splines, with close to 0 play?

 

Cheers,

Patrick

 

Hi Patrick, just from the logical thinking there are millions of cv jointed cars

happily driving through the world and we stay with that trouble.

 

My thought is to blame the manufacturer for making bad splines.

As they need to be hardend what makes them a little bit bigger

my explanation is that the splines are símply made to small

that they will fit whatever is done to them in the hardening process.

 

So my remedy was to weld the axles together from stock VW axles.

I learned from GKN that this was done to Rally cars with success.

So I found a company who does that job for 400 Euros per pair

but it cured the problems.

 

I have them in the V8 for years,

Plating from my view will add some more trouble

nickel instead of a hardened surface is nonsense

and hard chromed might do the job but I am not

the chemist to say what it will do to the material.

German term is "Wasserstoffversprödung)

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Hydrogen embrittlement Bruce:)

The diffusion of hydrogen atoms in the metal can result in brittle fracture.

Especially high strength steels ( which a drive shaft of decent quality is) are suseptable.

The hydrogen can be released during electrolytic plating, the process normally used for "chroming"

Regards,

Waldi

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  • 2 months later...

Gentlemen,

Having read this thread I want to replace the rebuilt hubs on my 4A which have been on the car for two years. I have uprated drive shafts which have not caused any problems. I only use the car for normal motoring, no motorsport so uprated hubs seem to me to be over the top.

Moss have new original type hubs in stock and they are currently offering a discount on them. Are the Moss new hubs OK or have there been bad experiences of them, are they of Chinese origin?

Thanks.

Graham

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Hi Graham,

I have the Moss hubs fitted to my 4A - Why

 

CV shafts are fairly new to our cars so any long term problems are unknown. There have been short term failures (not many).

 

 

The Moss hubs are built to the Standard Triumph design. So we know the weak points - bearing failure and the stub axle failing

The bearing will eventually fail (100,000 miles or so)

The inner stub axle can break - typically on very old hubs 40 - 50 years old. Did any fail under normal conditions during the 60's and 70's - I don;t know.

 

Rebuilt ST hubs generally only have the bearings/seals replaced so the suspect stub axle is still very old and waiting to fail.

 

The Moss hubs, on first appraisal, are not perfect. They feel very stiff. The 0.003 - 0.004" end float can't be detected.

I have four old original ST hubs. All four hubs feel nice and smooth, they are not stiff, 3 have NO end float.

 

I disassembled one hub to see what goes on inside and have come to the conclusion that if you follow the ST WSM you will not be able to set the end float accurately, if at all.

The seals/grease cause too much stiffness to detect the very small play required by the WSM. I'm sure a suitable massive jig could sort that.

 

I needed two hubs last April as mine were 50 years old.

I bought 2 hubs from Moss and said to Jeff (their R&D man) that I would monitor them fortnightly and report back as and when anything happens.

I ran them up on my lathe (400rpm) for 15 minutes - they got pretty warm going towards bloody hot. However there was no airflow or additional heatsink.

 

They have been fitted since April 4th 2017 and have covered 14,000 miles.

There is no play in the bearings

I still can't detect any end float

Rotating the wheel at the tyre and they spin freely.

 

The benefit of the new hubs is that the stub axle is only a year or so old. So they should have a good 30 year life - unlike any rebuilt old ones.

 

Where are the parts made.

The stub axle may well be forged in China (my guess) but it is machined in Sussex by a well known stub axle maker who does Jag, Daimler etc as well (I don't know his details though).

The bearings are expensive good quality ones.

 

Would I recommend them - except for the initial stiffness and not being able to feel the end float they are what ST made.

Is the stiffness and issue - Not to me. They free up and feel OK after a good number of miles.

Is the end float an issue - Not to me. Excessive end float or compression of the crush tube will cause early bearing failure - mine are OK after 14,000 miles.

The new stub axle should ensure that you will not lose a wheel for at least 30 years.

 

Roger

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I still believe that the major cause of failure of the stub axles is sagging suspension. We all know that the original rear springs on TR4As were too soft and allowed bottoming. Spring sag is common on all of the cars from 4A to TR6 as they age. Once that happens, and bottoming becomes more frequent, the stub axle takes all of the impact and will fail. Even if the car has been restored, you do not know the previous history of the car and I know of no testing procedure that will predict when the stub axle will fail. So I would suggest that replacing your springs should be done as well as replacing the driveshafts or hubs.

 

Having spent all that time, money and effort restoring my car, I did not want to have a stub axle failure, so I fitted the TR-Nord drive shafts and hubs. The whole design appears much stronger. We have done about 25,000 miles so far with no problems. I am running GoodParts 470lb rear springs and Koni telescopic shocks. The ride is fine.

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Hi Rockie,

that is an interesting thought.

It may work if there were no bump stops and solid rubber tyres. But as it is there is significant cushioning to protect the stub axle.

 

Sadly that is only my view and not very scientific.

 

With all things the whole system needs to be in good condition to work correctly.

 

There is one saving grace - the stats show that serious failure (wheel departure) was very rare, if at all, in the first 20 or 30 years of use.

So time is a great factor in the failure of these stub axles

Like many important aircraft components perhaps these hubs need to be 'lifed'.

 

Roger

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I had a wheel come off. Everything else was in order. No sagging either with only mild negative camber when laden. Bump stops all in place.

 

I think the stub axle's weak part is the threaded part at the end. It's churlish to say it was under-engineered because like Roger, I suspect failure of this part for the projected original lifespan of the vehicle (and well beyond) seems to have been rare or perhaps even non-existent. But I think it's fair to call it a RELATIVELY weak component.

 

And they ARE failing now. If you've had a wheel come off when the car is in motion I can assure you it is something you will do ANYTHING to avoid. So it was Limora CV shafts for me. Straight swap and the other benefit is that it transforms the way the car drives, notwithstanding any possible failure of stub axles. The car is just better. Spline lock is not quirky or endearing!

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Hi Steve,

how old was your ST hub at failure?

 

The CV shaft has its followers but there have been failures. The good thing is the wheel doesn't depart the car (as far as I know)

 

I'm happy with a new/young hub. Anything rebuilt will always have a question mark over it.

The weak area on the stub can not be inspected for cracks. Due to the nature of the material, failure happens in a very few cycles.

 

Spline lock is not quirky or endearing - I'm not sure I have experienced this.

 

Roger

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I had a wheel come off. Everything else was in order. No sagging either with only mild negative camber when laden. Bump stops all in place.

 

I think the stub axle's weak part is the threaded part at the end. It's churlish to say it was under-engineered because like Roger, I suspect failure of this part for the projected original lifespan of the vehicle (and well beyond) seems to have been rare or perhaps even non-existent. But I think it's fair to call it a RELATIVELY weak component.

 

And they ARE failing now. If you've had a wheel come off when the car is in motion I can assure you it is something you will do ANYTHING to avoid. So it was Limora CV shafts for me. Straight swap and the other benefit is that it transforms the way the car drives, notwithstanding any possible failure of stub axles. The car is just better. Spline lock is not quirky or endearing!

I also went for the Limora CV Shafts, my only criticism of them was that you have to have had tool making experience to mate the male splines with the female splines as it has to be an interference fit as per Limora? Now as already stated before, I know of at least 6 cars that have become 3 wheelers and they were not all 30 to 50 years old! but were high mileage triumph 2000s that were 2 to 3 years old in the 1970's. So I do not subscribe that it only happens to old cars. Also you have to ask yourself why did GKN come out with a CV kit years ago?

 

Bruce.

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I also went for the Limora CV Shafts, my only criticism of them was that you have to have had tool making experience to mate the male splines with the female splines as it has to be an interference fit as per Limora?

Bruce.

 

That's interesting Bruce. Mine came fully assembled and I just whacked 'em on. Luckily I had no stripped stud holes in the trailing arm. No adjustments needed. I seem to recall I had to measure something or other but my car was within their tolerance. I never felt whether there was any 'slop' in the CV assembly but even if it could have been felt off the car the actual experience off using them was utterly smooth, no sense of any backlash or play whatsoever. Just made it a much nicer car.

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That's interesting Bruce. Mine came fully assembled and I just whacked 'em on. Luckily I had no stripped stud holes in the trailing arm. No adjustments needed. I seem to recall I had to measure something or other but my car was within their tolerance. I never felt whether there was any 'slop' in the CV assembly but even if it could have been felt off the car the actual experience off using them was utterly smooth, no sense of any backlash or play whatsoever. Just made it a much nicer car.

Hi Steve! I have to agree with you about a much nicer car to drive and I also notice that my car was easier to push when it was on the flat. I have done over 5K now and so far so good. When your wheel came off did you escape without injury and not too much damage to the car? I was in a TR4 IRS when it happen to us and the left wheel passed us on the inside as we were entering a drive but it wrote the rear wing off! I am glad that we were going at 5MPH.

 

Bruce.

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Hi Steve! I have to agree with you about a much nicer car to drive and I also notice that my car was easier to push when it was on the flat. I have done over 5K now and so far so good. When your wheel came off did you escape without injury and not too much damage to the car? I was in a TR4 IRS when it happen to us and the left wheel passed us on the inside as we were entering a drive but it wrote the rear wing off! I am glad that we were going at 5MPH.

 

Bruce.

 

Well the car had belonged to me and my Dad since the '80s. It eventually went off the road for many years and then we managed to get enough money together to restore it (Clive Manvers did the work - RIP Clive).

 

On the very first journey back from Clive's after about 12 years of inactivity and restoration I was driving and turning right at about 10mph and then...bang. For a moment it was disorientating. Then the realisation dawned; the blo*dy wheel's come off! It had somersaulted in the arch and creased the rear wing lip in about four places. The trailing arm picked up some mighty scrapes. We were unhurt - other than the embarrassment! I've read of stories of 2500 and Stag owners on the dual carriageway and they see one of their rear wheels overtake them - horrifying!

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Ok you may be a masochist (and if you are its fine by me) but 5K pushing? I've been on a few economy run's in the past but never seen anyone that determined :D

Alan

Hi Alan, I am no masochist but I would not like to have a wheel come off at 70 to 80 MPH on the motorway as that could be terminal for me and I am glad to date that I have not heard of any stories like that.

 

Bruce.

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Hi Alan,

 

the handbook for my 1958 Super Snipe, which is by British standards something of a behemoth of a saloon, cheerfully advises that in emergency the car can be pushed to a speed of 25mph and then engage Drive . . . . it's a Borg Warner DG automatic gearbox. Considering just how much effort it is to push the car at all, the idea of achieving 25mph is more than somewhat boggling. Possibly a new challenge for the World's Strongest Men ?

 

Cheers,

 

Alec

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