CV-halfshafts WARNING!

[RogerH]

Hi Folks,

thankfully we are blessed with a variety of solutions.

However may I put forward the question - have we got a problem.?

 

People are buying and using rear hubs (the standard design) that have axle shafts up to 50 years old.

 

How many failures were there in the early days ? - say up to 30,000 miles - this could be 3 to 10 years of use for average driving.

 

Although the design looks a little delicate (a small area holding it all together) the mechanical tie up of the parts makes failure less likely in a normal time frame.

The failure area of the axle is under serious tensile load with the big nut torque - but that is what the material is specified for. It doesn;t like bending and so it is loaded in the tensile mode.

One problem with these high tensile steels is they do not hang around when cracking. Once any cracking starts it will fail very quickly - not possible to be inspected.

 

So is there an answer?

Clearly all the modern versions of this hub have some sort of issue.

Bruce is a very capable engineer and is all too well aware that fitting some of these units is not child's play.

 

The standard hub, as now made by Moss, has had some teething troubles but is made from quality materials.

If you were to use these hubs and employ and arbitrary life on them then I think a safe situation could be had. 100,000 miles (10 years or more) could be an interesting life.

 

Modern cars with rubber/plastic cam belts have a 60K miles life and people are happy to change them at whatever cost.

So why not change the hubs are a reasonably long period.

 

If was up to me I would ban the sale of refurb'd hubs that still use the original axle shaft.

 

Roger (tin hat on)

[astontr6]

Hi Folks,

thankfully we are blessed with a variety of solutions.

However may I put forward the question - have we got a problem.?

 

People are buying and using rear hubs (the standard design) that have axle shafts up to 50 years old.

 

How many failures were there in the early days ? - say up to 30,000 miles - this could be 3 to 10 years of use for average driving.

 

Although the design looks a little delicate (a small area holding it all together) the mechanical tie up of the parts makes failure less likely in a normal time frame.

The failure area of the axle is under serious tensile load with the big nut torque - but that is what the material is specified for. It doesn;t like bending and so it is loaded in the tensile mode.

One problem with these high tensile steels is they do not hang around when cracking. Once any cracking starts it will fail very quickly - not possible to be inspected.

 

So is there an answer?

Clearly all the modern versions of this hub have some sort of issue.

Bruce is a very capable engineer and is all too well aware that fitting some of these units is not child's play.

 

The standard hub, as now made by Moss, has had some teething troubles but is made from quality materials.

If you were to use these hubs and employ and arbitrary life on them then I think a safe situation could be had. 100,000 miles (10 years or more) could be an interesting life.

 

Modern cars with rubber/plastic cam belts have a 60K miles life and people are happy to change them at whatever cost.

So why not change the hubs are a reasonably long period.

 

If was up to me I would ban the sale of refurb'd hubs that still use the original axle shaft.

 

Roger (tin hat on)

Hi Roger!

The problem that I have with the TR suppliers is that they do not work to tried and tested UK engineering practice. The base of which is an engineering drawing but use only a sample of what they want and say ' I want one of them'? This practice I have had confirmed by one of the main suppliers. You and I know that this is a very dangerous practice and does not take into account safety critical items! My own view is that if Moss are re-making hubs from new, they should incorporate modern automotive bearing practice and make the stub axle larger in o/d and thicken up wheel the hub flange. These are all areas that my Limora hubs have improved upon?

 

Bruce.

[TriumphV8]

It is not as Roger said, swap old hubs against new and everything is okay.

If we do so, we swap former Stanparts of medium quality against cheap Charly from China.

 

The old guys of us will still remember that we thought in those days Stanparts are not that good

and we looked for better. Today many claim that only original quality = Stanpart is the way to go!

That gives an impression what we can expect from cheap China products.

 

Many suppliers do no longer want to be in the business with Triumph parts because other pay more.

Remember our last díscussions about aluminium tanks from Wiltshire.

Triumph owners mostly look more on price than on quality.

We now have the courios situation that prices got higher and higher but the quality often is on

a pretty low level that does not even meet the lower TR prices.

 

So most suppliers try to make things cheaper and cheaper until they fail quickly.

Let us have a look at the Limora cv shafts. They are supplied earlier from TR-Nord

that are made from GKN high quality joints, completed with some individually made parts

where except the joint size and quality of bearing housing there was not much to claim.

 

They took the cv shafts to MAPCO and told them to make it cheaper.

Some say they still work but also several people had trouble.

Some details got worse than before.

 

Also the new hubs for universal shafts made trouble from time to time.

Buying them from new is NOT the guarantie for safety.

Opposite to that I would vote for refurbish original by a specialist

and use magnetic particle inspection for the axle.

Alternatively Cosworth and some other suspects offer high quality hubs but

for the price close to a complete set of CV shafts with new hubs.

 

Its often claimed the character of a TR6 is not the same with modified parts.

Let me tell you, lost wheels or gas bubbles in the PI do not form the character

of our TRs. Also bad suspension is not that much required to get a Triumph feeling.

Even the V8 gives a unique feeling not changing the TR impression but underlying

its typical impression of a British sports car, hard but reliable and a teammate.......

[RogerH]

It is not as Roger said, swap old hubs against new and everything is okay. I didn't actually say that

If we do so, we swap former Stanparts of medium quality against cheap Charly from China.

The medium quality Stanpart has lasted 50 years with a few failures. Up to 30 years with normal driving there were no failures. How old do you want these hubs to be before changing.

The Moss hub is NOT made in China but in the UK Correction - the stub axle is forged in China and then machined and built in the UK. 12/7/17 15.37

 

The old guys of us will still remember that we thought in those days Stanparts are not that good

and we looked for better. Today many claim that only original quality = Stanpart is the way to go!

That gives an impression what we can expect from cheap China products.

 

Many suppliers do no longer want to be in the business with Triumph parts because other pay more.

Remember our last díscussions about aluminium tanks from Wiltshire.

Triumph owners mostly look more on price than on quality.

We now have the courious situation that prices got higher and higher but the quality often is on

a pretty low level that does not even meet the lower TR prices.

 

So most suppliers try to make things cheaper and cheaper until they fail quickly.

Let us have a look at the Limora cv shafts. They are supplied earlier from TR-Nord

that are made from GKN high quality joints, completed with some individually made parts

where except the joint size and quality of bearing housing there was not much to claim.

 

They took the cv shafts to MAPCO and told them to make it cheaper.

Some say they still work but also several people had trouble.

Some details got worse than before.

 

Also the new hubs for universal shafts made trouble from time to time.

Buying them from new is NOT the guarantie for safety.

Opposite to that I would vote for refurbish original by a specialist

and use magnetic particle inspection for the axle.

Mag Particle inspection of the original hub axle is a waste of time (you may get lucky) The metal characteristics of these high strength alloy steels is such that once cracking starts it will propagate very rapidly and fail. Replacement with new at timely intervals is the only safe solution.

 

Alternatively Cosworth and some other suspects offer high quality hubs but

for the price close to a complete set of CV shafts with new hubs.

 

Its often claimed the character of a TR6 is not the same with modified parts.

Let me tell you, lost wheels or gas bubbles in the PI do not form the character

of our TRs. Also bad suspension is not that much required to get a Triumph feeling.

Even the V8 gives a unique feeling not changing the TR impression but underlying

its typical impression of a British sports car, hard but reliable and a teammate.......

 

The Stanpart hub was designed very well, otherwise it would not have got to this old age and produced what is now a problem.

If, like modern cam belts, they were changed in a timely manner lost wheels etc would be an unknown event.

 

Roger

 

 

Edited July 12, 2017 by RogerH

[harrytr5]

So what is the best solution and supplier of up to date with all known problems ironed out?

I have fitted CDD cv joints to a mates car a year ago and no problem to fit and he is delighted with it.(This was his first car 40 plus years ago and he knows it inside out)

I love the info from qualified engineers on this subject and look forward to that only.

I fitted Cosworth hubs and GKN driveshafts 14 years ago.Had to change out the bearings when my TR5 nearly drowned in a river in the 2007 floods in Malvern.

Rescued by the international North London Group the following day.Where did the chest height floods disappear to so quickly?

Regards Harry

Edited July 11, 2017 by harrytr5

[astontr6]

It is not as Roger said, swap old hubs against new and everything is okay.

If we do so, we swap former Stanparts of medium quality against cheap Charly from China.

 

The old guys of us will still remember that we thought in those days Stanparts are not that good

and we looked for better. Today many claim that only original quality = Stanpart is the way to go!

That gives an impression what we can expect from cheap China products.

 

Many suppliers do no longer want to be in the business with Triumph parts because other pay more.

Remember our last díscussions about aluminium tanks from Wiltshire.

Triumph owners mostly look more on price than on quality.

We now have the courios situation that prices got higher and higher but the quality often is on

a pretty low level that does not even meet the lower TR prices.

 

So most suppliers try to make things cheaper and cheaper until they fail quickly.

Let us have a look at the Limora cv shafts. They are supplied earlier from TR-Nord

that are made from GKN high quality joints, completed with some individually made parts

where except the joint size and quality of bearing housing there was not much to claim.

 

They took the cv shafts to MAPCO and told them to make it cheaper.

Some say they still work but also several people had trouble.

Some details got worse than before.

 

Also the new hubs for universal shafts made trouble from time to time.

Buying them from new is NOT the guarantie for safety.

Opposite to that I would vote for refurbish original by a specialist

and use magnetic particle inspection for the axle.

Alternatively Cosworth and some other suspects offer high quality hubs but

for the price close to a complete set of CV shafts with new hubs.

 

Its often claimed the character of a TR6 is not the same with modified parts.

Let me tell you, lost wheels or gas bubbles in the PI do not form the character

of our TRs. Also bad suspension is not that much required to get a Triumph feeling.

Even the V8 gives a unique feeling not changing the TR impression but underlying

its typical impression of a British sports car, hard but reliable and a teammate.......

Andreas,

Mapco is hardly a hole in the wall German company, also when you refer to GKN quality joints? GKN- Driveline was sold to a German competitor well over 20 years ago! So where did TR-Nord's ones actually come from and who made them?

 

Bruce.

[TriumphV8]

Andreas,

Mapco is hardly a hole in the wall German company, also when you refer to GKN quality joints? GKN- Driveline was sold to a German competitor well over 20 years ago! So where did TR-Nord's ones actually come from and who made them?

 

Bruce.

 

Hi Bruce during my problems with the CV shafts for the V8

I was directed to a sports department from GKN.

It was located in the area of Düsseldorf.

 

They prepare a lot of cars for Rallye and I was impressed how helpfull they are.

While German Rallye Champions and well noted Tuners are phoning they found

time to address my problems and provide me with help.

 

So they still exist and are named GKN, maybe the owner has changed in the background.

That was about five years ago.

 

A very good supplier for all these goods is ELBE in Köln.

They can cut an existing shaft, shorten it and weld it together.

They also do that for Rallye purposes.

If requiered they do balancing and whole refurbish of prop- and driveshafts.

Expensive but very good.

 

My TR Nord parts contained cv joints printed GKN on and the other parts

seem to be custom made from a supplier. They are all stamped and have

a good finish. Wheel bearing is a normal spare part from VW.

 

Actually I use joints from a friendly supplier close by in Wuppertal.

He was very helpfull sorting my problems out and gave me the hint with GKN sports department

and announced me there that they made a date and had time.

In my opinion the problem is not in the joints but in the shaft and the bearing housing

and at some TRs in the incorrect space from lever to diff.

Edited July 12, 2017 by TriumphV8

[Alec Pringle]

Back in the day, late 60s to mid 80s, I drove 2000, 2500, 2.5, TR4A, TR5, TR6 and Stag on the road and in all sorts of minor competitive stuff, without ever having to replace more than a UJ. Some of those cars had covered 6 figure mileages. I don't recall ever seeing anyone else with a three-wheeled Triumph, road or track.

 

The Triumph rear axle may not have been the best of all possible designs, but it did the job back in the day.

 

Damned if I can see why a pukka reproduction of the original should not suffice for an IRS Triumph in relatively original spec.

 

Different matter if you prefer bloody great modern wheels and tyres and a few dozen more horses than the original, but then you're not driving a TR you're driving a hot rod.

 

Cheers,

 

Alec

[RogerH]

Hi Andreas,

I have sent you a PM

 

Roger

[OAF939M]

Alec very wise words.

If you want a modern beast, buy one!

Don't screw up an old classic.

I also have a 1936 Riley Special with leaf springs, rod brakes, pre-selector gearbox, and love it.

It is 1100cc,twin cam, cross-flow head, it was expensive in the day and they eventually went broke!

[Rockie51]

I agree with the idea of keeping the classic look and feel of our cars, but I also think that sensitive modifications enable us to enjoy that feeling over much greater mileages in greater safety. My car has the TR Nord driveshafts as well as an alternator, MX5 seats and a RetroSound radio. So we have greater safety and comfort from the seats and driveshafts, a reduced likelihood of a flat battery and the ability to listen to music from the iPhone (at low speeds!). None of these features is "in period" but they do make the car more usable, and allow us to do things like crossing Australia from East to West.

 

The issue of broken stub axles became of sufficient concern to TSOA here for a search to be done to find the best possible replacement. Some body parts that were replaced on my car when it was restored came from a TR6 that rolled at Phillip Island after a stub axle broke......

 

I wonder if part of the problem is not only the age of the cars but the fact that the rear springs, especially on the 4As, were too soft. As they aged and sagged, bottoming became more of a problem and most of the impact was taken by the stub axle, hastening its' demise.

[harrytr5]

I will be changing out my Cosworth hubs (Racetorations) and GKN uprated driveshafts very soon to CV so the pair will be for sale if any one is interested.

PM me if you like.

Regards Harry.

[aardvark]

Why you doing that Harry? Cheers dave

[harrytr5]

Dave,

After fitting a pair of CDD CV joints to a mates car and he has had it forty plus years so knows the car inside out he is over the moon how it has transformed the drive. He had uprated GKN shafts but needed to change the iffy hubs.

I just fancy doing it to mine to see what he is on about.

Regards Harry

[Ragtag]

Alec very wise words.

If you want a modern beast, buy one!

Don't screw up an old classic.

 

 

I also have a 1936 Riley Special with leaf springs, rod brakes, pre-selector gearbox, and love it.

It is 1100cc,twin cam, cross-flow head, it was expensive in the day and they eventually went broke!

 

Do as I say, not as I do?

 

Presumably your 'special' was originally a Falcon or a Kestrel Saloon at some point! (In case the emoticons don't work, I am pulling your leg,,,,,a bit).

 

I bet if you were offered a supercharged 12/4 engine for no money you would take it (I know I would)

[15eren]

Hi all

 

Many have now commented the thread, and many new aspects has come into the discussion.

And of course there will be many advantages in buying and installing CV-jointed halfshafts including hubs, perhaps also regardles of the quality (or lack of quality) of the product.

No doubt that You get rid of the risk of a binding spline and You might also minimize the risk of loosing a wheel in hard cornering.

 

But, hand on Your heart, the most common reason to buy and install these not cheap CV-jointed halfshafts, is to get rid of clonking from bad UJ´s and from worn splines in the half-shafts and to get fit-and forget hubs and shafts.

 

And in that matter my experience untill now has been, that Your money are wasted. Simply because the quality of the components involved are much too low and materials and accuracy in making and setting up the hubs is long behind what You might expect from a serious company.

 

And PM´s to me from other forum-members about similar issues shows that I am far away from being alone with that experience regarding this company.

 

It is worth to mention, that my experience is only from this one company and there may be others who are serious, has the volume and are eager to do anything to get satisfied customers.

 

Cheers

Tage

Edited July 14, 2017 by 15eren

[stuart]

Dave,

After fitting a pair of CDD CV joints to a mates car and he has had it forty plus years so knows the car inside out he is over the moon how it has transformed the drive. He had uprated GKN shafts but needed to change the iffy hubs.

I just fancy doing it to mine to see what he is on about.

Regards Harry

I wouldnt, you have the best setup that will take considerably more power than your ever going to be able to put through them, also its a lot easier to change a bearing if required

Stuart.

[TriumphV8]

Long before I had the actual big V8 in the car I destroyed the universal joints often.

I changed them every year and power was the 3.5 V8 with about 180 BHP.

 

The reason is the lowering rear that causes large angles for the driveshafts.

The needles in the joints are no longer located in a rectangular position

and from that do not transfer the load in a line from outside to inner piece of the

universal joint. This causes point loads at the top of the inner cross what causes marks.

 

So the limit of the universal joints is not that far away as expected.

They were designed for the TR4 and can withstand a little bit more.

People who did serious tuning to the TR6 and/or like to accelerate

also quickly in first gear will definitely suffer within month from rough

running of the driveshafts.

[astontr6]

Long before I had the actual big V8 in the car I destroyed the universal joints often.

I changed them every year and power was the 3.5 V8 with about 180 BHP.

 

The reason is the lowering rear that causes large angles for the driveshafts.

The needles in the joints are no longer located in a rectangular position

and from that do not transfer the load in a line from outside to inner piece of the

universal joint. This causes point loads at the top of the inner cross what causes marks.

 

So the limit of the universal joints is not that far away as expected.

They were designed for the TR4 and can withstand a little bit more.

People who did serious tuning to the TR6 and/or like to accelerate

also quickly in first gear will definitely suffer within month from rough

running of the driveshafts.

Andreas,

 

When you talk about 'lowering of the rear' I assume you are referring to 'suspension whined up' where the rear springs are being shorten (compressed) by the torque from the drive shafts? Years ago I got 400lb rated springs from Triumph Eng. and never had a problem after that, they lasted 40 years, before one of them went soft! They were replaced by similar rated springs from Moss. But BL uprated the rear springs at least 4 times that I know of during the production life of the TR6. I never replaced a U/J, because of wear, only one of the splined shafts + 2 U/Js because while I was replacing the splined shaft! But I always used CV grease as per Hardy Spicer.They were re-greased every other year! So is there something to be learnt here?

 

Bruce

 

Bruce.

[astontr6]

Hi Folks,

thankfully we are blessed with a variety of solutions.

However may I put forward the question - have we got a problem.?

 

People are buying and using rear hubs (the standard design) that have axle shafts up to 50 years old.

 

How many failures were there in the early days ? - say up to 30,000 miles - this could be 3 to 10 years of use for average driving.

 

Although the design looks a little delicate (a small area holding it all together) the mechanical tie up of the parts makes failure less likely in a normal time frame.

The failure area of the axle is under serious tensile load with the big nut torque - but that is what the material is specified for. It doesn;t like bending and so it is loaded in the tensile mode.

One problem with these high tensile steels is they do not hang around when cracking. Once any cracking starts it will fail very quickly - not possible to be inspected.

 

So is there an answer?

Clearly all the modern versions of this hub have some sort of issue.

Bruce is a very capable engineer and is all too well aware that fitting some of these units is not child's play.

 

The standard hub, as now made by Moss, has had some teething troubles but is made from quality materials.

If you were to use these hubs and employ and arbitrary life on them then I think a safe situation could be had. 100,000 miles (10 years or more) could be an interesting life.

 

Modern cars with rubber/plastic cam belts have a 60K miles life and people are happy to change them at whatever cost.

So why not change the hubs are a reasonably long period.

 

If was up to me I would ban the sale of refurb'd hubs that still use the original axle shaft.

 

Roger (tin hat on)

Hi Roger

 

Just to say that by chance I re-read the BL North-American Triumph Competition Preparation Manual for TR250, TR5 and TR6 - published 1969. To my surprise the manual confirms that there was a problem with the rear hubs 47 yrs ago - ref: Rear axles pg. 23 - where it says that the hub can move on the taper and advises you to only use the wide-key version, which was a modification by BL. However, it also states that the modified version should be lapped to the hub and lightly coated with Loctite. The flange is torqued to the factory spec. The previous version of the taper had a habit of pulling the key out of the key-way and was the reason for the increase in the size of the key. Therefore, to me, there seems to be an inherent problem with the original stub axle which has never been fully addressed and I question if the use of the larger key and key-way actually weakened the stub axle, leading to metal fatigue?

 

The only example that I have examined where the taper has sheared, I noticed that it had sheared immediately behind the key-way section. I don't know whether this is always the case. The other thing that is confirmed in this para is that the repeated bottoming of the rear suspension damages the UJs. This also confirms the thread on which Andreas wrote about on this particular subject, and therefore it is most important that the springs on the rear are rated to combat this problem. However, the manual doesn't give a recommended spring-rate but BL Special Tuning offered a 400 lbs rated spring to overcome this problem and subsequently the same rated spring was offered by SAH, who took over BL's special tuning for Triumphs.

 

Bruce

[stuart]

Most dont bottom out the springs on the bump stops but on the shocks as they are too long, anyone checked if the hubs that have broken have been fitted to cars with tube shock conversions?

Stuart.

[Alec Pringle]

I've seen the first hand detail of 4 hub breakages in the past 15 or so years.

 

One occurred soon after the car had suffered a puncture and whacked a kerb hard enough to shatter the alloy wheel on the n/s/r, which I think can be most likely attributed to that impact rather than its being fitted with tube shocks and 195 tyres.

 

The other three incidents did not seem to have been preceded by any impact situations, all three cars were fitted with tube shock conversions, two sported 195 and the third 205 rubber . . . . . there were other 'upgrades' involved but I can't recall all the chapter and verse.

 

In all four instances the car was two-up and loaded boot.

 

Cheers,

 

Alec

[Guest ntc]

I wouldnt, you have the best setup that will take considerably more power than your ever going to be able to put through them, also its a lot easier to change a bearing if required

Stuart.

+1 no brainer.

[ike551]

I have followed this thread with interest and have resisted replying until now having been the victim of a broken rear of side shaft two days before the international weekend

I was alone in the car , the weekend before we had been to the Red Rose weekend ,driven just under 600miles , the last being the dash home at approx 200 motorway miles , loaded and two up

The Tr was parked up , on the following Wednesday Evening I was on my way to Luton Hoo via the M25 onto the M1 when my sat navy took me off the M1 at Hemel Hempstead because of traffic congestion

It was on the A414 slip road after a couple of stop/starts in heavy traffic that the tr wheel came adrift launching the car into the air as the inertia took me over the wheel and dumped me on the tarmac

I got out not really knowing what had happened until I saw my wheel behind me , as I was in a slip road for a motorway I was forced to accept a police recovery , they have cart blanc to remove a vehicle hazard as quick as possible without worrying about vehicle damage , on top of that it cost £200 to be taken to a garage 4 miles away , £150 of that was just for putting the car on the transporter

When I think of what could have been the previous weekend and moments before it is not an experience I wish to repeat

So I spent all day Saturday of the international researching drive shafts and hubs

My conclusion was that I never want to be in a position where my hubs could EVER come off again so I bought CV drive shafts

Clonks I can live with, it's called driving classic cars , but here it is I WILL LIVE or if you wish, not die with only three wheels on my TR

We have a car show this weekend and my wife refuses to drive the car with our granddaughter in it while I drive the Cadillac , so it's not going

The alternative is to sell the car and buy an MX5

Your life , your choice , my life my choice , lucky my interior is brown is all I can say

 

Howard Pryor

You know the car , Ferrari blue TR6 mildly tuned , driven like a sports car should be driven

[TriumphV8]

Hi Bruce,

my lowering comes from the fixing point of the rear lever.

The brackets had to find a place to be fixed and that was the frame.

It is simply positioned to low.

I used adustable brackets and turned one side as much up as possible

and set the camber with the other bracket. Better but not good.

 

You are right, the harder rear spring helps a lot on this problem.

Also driving in the mountains of Italy/Austria it helped me because when

accelerating out of a tight corner there the axle bottoms and if there

is a dimple in the road the whole car is close to jump.

 

Unfortunately the riding comfort was a mess and because we do holidays

with the car it did not get the WAF (wife approval factor)

I had one of the harder springs from MOSS, bought three sets and tried out.

With no doubt, road holding was very good......

In the end my choice was the BASTUCK spring set, a compromise and

with the Bilstein shocks and the cv joints best solution for me.