TR4a Rear Hubs.

[pampa]

I have had the stub axle shaft shear off  loosing the wheel and shattering the housing on the trailing arm to pieces. I see Rimmers advertise an uprated H/D driveshaft and hud and also an uprated CV jointed shaft however they can't give me any information on what is really uprated and particularly the stub axle which breaks. Has anyone had this problem and know of a fix or experience with the Rimmer items I would be grateful for any info.The car when it is straightened out won't be going back on the road until I fit some sort of major fix. After my accident my brother checked his TR6 and found a fractured stub axle ready to part company as well.

[rcreweread]

Hi - sorry to hear about your nasty experience but glad you are OK albeit the car didn't get off so lightly.

I have some refurbished trailing arms to sell if thats of any use -which side was it or would you prefer to fit a new pair?

I suspect the uprated driveshafts & hubs Rimmers are selling will be provided by other manufacturers - A company called CDD ( Classic Driving Developments) may have supplied them and I'm sure if you speak to them direct, they will be able to answer your queries  - https://www.classicdrivingdevelopment.co.uk/   - I have no connection with this company other than as a customer. SC Parts also do them and I believe they are made in Germany by Limora

There is a lot of previous discussion about uprated driveshafts and hubs here on the forum, if you do a search -sometimes easier to put your search enquiry into google requesting to search the TR Register Forums

PM me if you are interested in the trailing arms

Cheers Rich

[RogerH]

Hi Pampa,

we are now seeing quite a few shaft failures as they are getting to 50 years of age.

Their is a mountain of old posts on here outlining what people did and recommend.

If you want to stay with the existing design that will be good for another 30 - 50 years then I would suggest getting your drive shafts from here -

https://gb.kompass.com/c/proptech-ltd/gb82467406/

Moss supply NEW hubs - assembled on their premises at Hanworth middx.   https://www.moss-europe.co.uk/hub-assembly-rear-outer-new-402347.html?assoc=114263

I have no connection with the above but use their products.

Do NOT use a refurbished hub as it will contain an old shaft.

 

Roger

 

Roger

 

[Motorsport Mickey]

Good news to know you escaped from what could have been a very dangerous occurrence. Your latest failure of these IRS cars (TR4a -6) rear hub components just underlines the discussions we've been having over the last 3 or 4 years regarding these components now dying from old age.

For more information try the search box where you'll find many threads with failure of various different components of/in the rear hub, and we have on a few occasions had a car inversion so the severity of a failure here cannot be underestimated. The same "Innsbruck" rear suspension design is used on Stags and even they (often they are driven more sympathetically, think nun wearing slippers !) are having rear hub and or stub axles failures occurring. This is a failure of the hub on one of a pair of refurbished hubs bought and fitted by a Stag owner

and this is the second hub within 18 months of it's original refurbished fitment

This owner then binned the pair and bought two new hubs with their new stub axles etc.

The effort required to strip these items to refurbish them is immense, often a 20 ton press and/or heating is used alongside a robust bearing splitter and these acts are not kindly to components nearly 50 years old. Cracks can be caused in some of the original components in places where "non destructive testing" cannot be applied (RogerH is the expert here) which means the owners of refurbished hubs carry on the process by driving them until the "destructive" part of the testing process is reached.

Fit new rear hubs whatever else you prefer as driveshafts is secondary and your choice.

Mick Richards

 

Edited January 9, 2020 by Motorsport Mickey

[Andy Moltu]

The original hub design was fundamentally OK.

Rebuilding a 50 year old hub without replacing the stub axle is not a sound option. At best they will be old and fatigued and likely to have that process advanced by the forces required to take them apart.

Rebuild with a new stub axle is fine, however that can work out more expensive than a new hub which in turn isn't much cheaper than an uprated hub with CV jointed drive shaft (OK you have to buy a pair of them but if one wheel bearing is knackered the other is probably aging)

The CV jointed drive shafts give a smoother drive than the UJ ones which is why modern cars use them. The splines on worn standard shafts have a tendency to lock up and give the rear end twitch that the IRS TRs, Stags and 2000s are famous for but that is largely overcome by fitting shafts "Teflon" coated splines from the like of Proptech.

It's down to choice once safety has been taken care of.

[RogerH]

Hi Andy,

I agree with 99% of your post above.

But, I would suggest that the car manufacturers went over to the CV joints because they are actually cheaper to produce and fit.

Those UJ are little time wasters.

Indeed the CV has many advantages that may improve the humble TR.

Roger

[Waldi]

Reviving this post for new-comers on the forum.

My rear hubs were ok, no noticeable clearance on the bearings.

But after reading about several sudden broken stubaxle failures on this forum I decided NOT to wait with replacing my (likely) 50 year old hubs until the bearing clearance increased.

So I opted for the CV joint option (hubs and shafts)  like many others, and to my surprise this also eliminated the “clonk” of which I thought they came from the diff.

My units came from CDD, and I was impressed by the quality.

Yes, it is another expense, but I’m glad I did.

Waldi

[Jase]

1 hour ago, Waldi said:

Reviving this post for new-comers on the forum.

My rear hubs were ok, no noticeable clearance on the bearings.

But after reading about several sudden broken stubaxle failures on this forum I decided NOT to wait with replacing my (likely) 50 year old hubs until the bearing clearance increased.

So I opted for the CV joint option (hubs and shafts)  like many others, and to my surprise this also eliminated the “clonk” of which I thought they came from the diff.

My units came from CDD, and I was impressed by the quality.

Yes, it is another expense, but I’m glad I did.

Waldi

Do you have a link, sounds like a good investment when refurbing.

[monty]

On 1/13/2020 at 12:21 PM, RogerH said:

Hi Andy,

I agree with 99% of your post above.

But, I would suggest that the car manufacturers went over to the CV joints because they are actually cheaper to produce and fit.

Those UJ are little time wasters.

Indeed the CV has many advantages that may improve the humble TR.

Roger

I fitted the CDD units with CV joints around a year ago & noticed immediately the gear change felt a little more precise but main reason was to replace the hubs just in case & am glad I spent the money to do it.

[Colin Symonds]

4 hours ago, Waldi said:

Reviving this post for new-comers on the forum.

My rear hubs were ok, no noticeable clearance on the bearings.

But after reading about several sudden broken stubaxle failures on this forum I decided NOT to wait with replacing my (likely) 50 year old hubs until the bearing clearance increased.

So I opted for the CV joint option (hubs and shafts)  like many others, and to my surprise this also eliminated the “clonk” of which I thought they came from the diff.

My units came from CDD, and I was impressed by the quality.

Yes, it is another expense, but I’m glad I did.

Waldi

Yes mine is going in next month for full CDD CVs, nothing noticeably wrong with my hubs, but when I'm going backwards through a hedge on three wheels I don't want to be wishing I'd replaced my 55 year old hubs.

[RogerH]

Hi Colin,

 if they are that old then anything new (coat hangers etc)  would be an improvement   

 

Looking at the prices - the CDD shafts/hubs are quite comparable with new standard hubs/shafts.

 

Roger

 

[BlueTR3A-5EKT]

Now here is an interesting fact

Triumph original drive shafts w ithout hub are part number TKC853. That part number included the inner drive flange, the make and female slimes AND the outer stub axle    

   All was assembled with universal joints sliding spline gaiter and inner UJ stone protection gaiter.  

Did that mean Triumph expected the hub to be rebuilt onto that new stub axle when the axle shaft was renewed?

[Andy Moltu]

I have heard of hubs not being able to be separated by a 60 tonne press.

Not sure what that did to the longevity when finally split and rebuilt!

[Waldi]

11 hours ago, Jase said:

Do you have a link, sounds like a good investment when refurbing.

Here you go Jase, scroll down a bit to “Triumph”:

https://classicdrivingdevelopment.co.uk/

Waldi

[Malbaby]

There is a guy here in Australia that sells CV jointed drive shafts together with new hubs and importantly replacement diff axle/flanges [no need to have adaptors between the inner cv flange and the original diff axle/flanges].

.

[Jase]

On 6/25/2023 at 9:52 PM, Waldi said:

Here you go Jase, scroll down a bit to “Triumph”:

https://classicdrivingdevelopment.co.uk/

Waldi

Thanks

[Rockie51]

An important point to when fitting CV driveshafts is to check that the shock travel does not allow the shaft to over extend. It can pull the circlip that holds the joint together to be dislodged and cause the two halves to disengage. Result? Lack of forward motion. Mine came from TR Nord in Germany many years ago and have done about 35k fast miles. Our most recent trip involved travel on on of our major highways that had been heavily damaged by floods. The overextension could have happened then but the failure occurred one block from home.

I have Koni telescopics on the rear with the fitting kit that bolts through the wheel well to brackets that bolt back to the original shock mounts. I believe that they are the strongest method of fitting telescopics. The shafts were repaired and the top shock mountings moved up so that it should not reoccur. Make sure that the manufacturer gives you the specs for maximum wheel travel when you fit CVs.

[Motorsport Mickey]

True this..."An important point to when fitting CV driveshafts is to check that the shock travel does not allow the shaft to over extend."

Unknown to owners this can happen when working on the car. It's common for IRS owners to disconnect the rear shocks to obtain better clearance underneath, by allowing the trailing arms to drop to maximum droop. If you do, it can often overextend the CV shafts because they are made to work within the area covered by the shock absorber range, which is what restricts the trailing arms droop. If you want a full drop trailing arm, disconnect the CV flange inboard from the diff and easing the flange away from the diff, allow the entire shaft to move away from the diff so it doesn't extend, preventing overextension.

Mick Richards

[Cotswoldiver]

On 6/28/2023 at 10:04 AM, Motorsport Mickey said:

True this..."An important point to when fitting CV driveshafts is to check that the shock travel does not allow the shaft to over extend."

Unknown to owners this can happen when working on the car. It's common for IRS owners to disconnect the rear shocks to obtain better clearance underneath, by allowing the trailing arms to drop to maximum droop. If you do, it can often overextend the CV shafts because they are made to work within the area covered by the shock absorber range, which is what restricts the trailing arms droop. If you want a full drop trailing arm, disconnect the CV flange inboard from the diff and easing the flange away from the diff, allow the entire shaft to move away from the diff so it doesn't extend, preventing overextension.

Mick Richards

Mick

On an associated thought, I have a non IRS 1966 TR4A, the front of the car has all been sorted with the usual/recommended reinforced plates and poly bushes everywhere, but we didn't touch the back end - so with a 57 year old, what would also be prudent to sort out at the rear?

David

[Motorsport Mickey]

I think you've got the best of the bunch.

From comments made to me, the "live" axle TR4a US spec has the strongest hub and half shaft compendium of all. I've never raced these but I understand these combination hubs/halfshafts are sought after, by those that do compete. Stuart knows some more about these, but as standard components I would be happy to run these live axles in a non competition car.

Mick Richards 

[stuart]

50 minutes ago, Cotswoldiver said:

Mick

On an associated thought, I have a non IRS 1966 TR4A, the front of the car has all been sorted with the usual/recommended reinforced plates and poly bushes everywhere, but we didn't touch the back end - so with a 57 year old, what would also be prudent to sort out at the rear?

David

Apart from the usual outer axle tube oil seals Ive not touched my back axle since I rebuilt the car nearly 30 yrs ago dont be tempted to grease the hubs more than one stroke in 5000 miles as they have a habit of the grease getting through onto the linings. Other than that the only thing is check the back plates for a groove where the handbrake arm pivots. Those axles are generally used by the TR4 rally boys so you know theyre good.

Stuart.

[Drewmotty]

I’ve heard that the 4a half shafts are stronger but no one has been able to explain why. 
The TR4 ones are machined down from  large diameter stock leaving the bearing abutment with a radius blended into the shaft. 
The 4a shaft is made from stock the diameter of the shaft with a bearing sleeve shrunk on after machining. 
I assume that they are made of the same material and given that the weak point will be at the machined taper and the spline root I can’t see why the 4a shaft would be any tougher. 
With my production engineer hat on it looks like a cost saving change. 
A case of “ the emperors new halfshafts”?

Edited June 29, 2023 by Drewmotty

[Cotswoldiver]

15 minutes ago, stuart said:

Apart from the usual outer axle tube oil seals Ive not touched my back axle since I rebuilt the car nearly 30 yrs ago dont be tempted to grease the hubs more than one stroke in 5000 miles as they have a habit of the grease getting through onto the linings. Other than that the only thing is check the back plates for a groove where the handbrake arm pivots. Those axles are generally used by the TR4 rally boys so you know theyre good.

Stuart.

Thanks Stuart, will check that next week when its on the ramp

David

[BlueTR3A-5EKT]

The design of the rigid axle TR4A half shaft with the shrunk on sleeve was carried over to Dolomite Sprint.   That has an almost identical axle just different casing brackets and overall length, using same internals and hubs as TR.    They got tuned to quite high power levels by the factory and I do not recall Leyland ST offering uprated half shafts, or at least we never had them on the shelf.   

Edited June 29, 2023 by BlueTR3A-5EKT

[Tr4aJim]

David I have a 1965 live axle Tr4A. Two things to note:

- check the alloy “Distance Piece” located between the leaf springs and the axle tube. It has a mounting flange for the lever shock arm. A few years ago when I rebuilt the rear suspension on my car, I found a crack in this flange. As these are no longer available i turned to this forum, and was provided spares. However since then, a company in the US, RATCO, make replacements out of steel.

- the shackles that hold the leaf springs to the frame are specific to the TR4A only. None of the usual suppliers have them, though a few do list some as fitting the TR4A. They do not (ask me how I know). One of the ones on my car was a generic shackle (causing the rear of that spring to not hang correctly) that a PO had installed. Once again this forum came to the rescue and I was able to acquire 2 shackles.

Jim