TR4a Rear Wheel Bearing

[PaulAnderson]

I got the price from the pricing matrix on their web site where even now it still states £380.  Perhaps they need to update the web document.

Paul

[Rockie51]

I have mentioned a couple of times on the Register my theory that some of the stub axle failures are due to sagged springs and consequent bottoming. When the bump stop is compressed all of the impact is taken by the stub axle. Triumph fitted heavier springs to TR5s and TR6s, lessening the problem. While the larger number of failures on 4As may be due to age, it could also be due to the softer springs. I have GoodParts 470lb springs on the back of my 4A with Koni telescopics. It rarely bottoms. When I bought it 26 years ago it had worn driveshafts so I replaced them with CV ones with better hubs from TRNord in Germany. I have done about 30k miles so far.

Some of the replacement panels on my car came from a club member’s TR6 which rolled on the racetrack after a stub axle failure. Her roll bar saved her life. She did not buy another TR.

[Peterdick]

Trawled through this discussion cos I have a developing concern about my old rear hubs after an advisory at yesterdays MOT.  Was going to go for Moss new ones but this morning they tell me that the current lead time is at least 16 weeks!  

[monty]

Just collected 2 CV units (hubs & shafts from Classic Design Development after much thought, investigation & sleepless nights!

I found Alasdair very friendly & helpful @ his very tidy, clean & efficient looking establishment so took the plunge & purchased these units for piece of mind. Very impressive looking units. Just got to get them fitted now!

He did mention radius arms & the studs used to attach the backplates. A weak link due to fine threads into alloy? What experiences have others had with this when fitting new hubs & shafts?

[Motorsport Mickey]

There’s a dozen posts on it in the search facility, why not search and read up the options ?

But to cut to the chase… there are no radius arms only trailing arms and it’s likely some of your threads will come out as grey dust as you undo the nuts on the studs. You could

Helicoil the hole 5/16 th UNF to take standard studs (this will need the hole in the trailing arm for the studs drilling out to the Helicoil tapping size)…OR

Buy some hybrid 3/8th UNC studs ( counter intuitively these need a smaller hole than the 5/16th helicoil tapping size, they use the 5/16th hole the stripped 5/16th stud comes out of !) with 5/16 th UNF at the hub end for the nuts you are going to undo. Alasdair sells these and will also give you a free loan of a jig to drill and tap the bigger holes in the trailing arms.

Mick Richards

Edited May 21, 2022 by Motorsport Mickey

[Andy Moltu]

If the threads are shot, I would go with Mick.

5/16 unf  helicoils are readily available as are replacement standard studs.

The key thing is accuracy in drilling to make sure you drill and tap perpendicular to the surface or you may find it tricky to sled the hub on. I gather some of the racers dispense with studs and use hex bolts to negate the hassle of imperfect alignment.

However there are jigs like Alistair loans out but designed for drilling and tapping for 5/16 unf too.

These guys ship to the UK  and you can flog it after use or keep in your local club.  Mine turned up in just a few days from the states.

 

[monty]

28 minutes ago, Motorsport Mickey said:

There’s a dozen posts on it in the search facility, why not search and read up the options ?

But to cut to the chase… there are no radius arms only trailing arms and it’s likely some of your threads will come out as grey dust as you undo the nuts on the studs. You could

Helicoil the hole 5/16 th UNF to take standard studs…OR

Buy some hybrid 3/8th UNC studs ( counter intuitively these need a smaller hole than the 5/16th helix oil tapping size) with 5/16 th UNF at the hub end for the nuts you are going to undo. Alasdair sells these and will also give you a free loan of a jig to drill and tap the bigger holes in the trailing arms.

Mick Richards

Thanks Mick. Yes I have discussed this with Alasdair yesterday, I was just interested to know how others have got on with the trailing arms.

[Motorsport Mickey]

On 5/20/2022 at 12:45 PM, Motorsport Mickey said:

 

 

Edited May 21, 2022 by Motorsport Mickey

[Waldi]

On 5/20/2022 at 2:15 PM, monty said:

Thanks Mick. Yes I have discussed this with Alasdair yesterday, I was just interested to know how others have got on with the trailing arms.

My TR (TR6) did not need any repairs, so I just fitted new studs where needed. Think I glued them in with loctite, mainly to avoid any water or even worse, salt-ingress over time.

Waldi

[monty]

For those who are unable or unwilling to tackle this job themselves, I have found a classic car workshop here in the Cotswolds happy to do the work. After struggling to find somewhere reasonably near I finally got the job completed almost on my doorstep! Had to wait a couple of weeks or so but then anybody any good is busy @ the moment! (One of the biggest TR names never even replied to emails or returned phone calls!). If anybody is contemplating having the work done then PM me & I will happily pass on their details. Only just picked up the car but nothing has fallen off so far! Suffice to say they restore high end Astons, Jags & the like as well as our cars!