Replacing rear hub bearing

[Sheepdip]

Every year for MOT I find play in rear hub bearings, tighten up slack with locknuts with a drop of loctite to stop them turning (the tabs are knackered now) but still the play comes back. Replacement shafts are expensive so was looking to replace the bearings myself with the helpful press from garage but have heard of problems with bits breaking afterwards, any advice welcomed. NB I also have acouple of Datsun driveshafts was going to adapt so may do these at same time.

Cheers

Paul

[mike@thenook]

Hi Paul,

I have original hubs but they were rebuilt when they were modified with Datsun driveshafts. The UJ's on the Datsun side of things are considerably larger that normal Stag ones and the shafts themselves 'bomb proof'

I have checked my hubs fairly regularly on the car and there is always a little bit of play in them but this weekend I checked them properly with a DTI and the end-float is well within the manual tolerances, it has never got any more than it is now.

I would say that if there is significant play (manual states 0.002- 0.005 in or 0.0508 - 0.127mm) then I would probably not rebuild them unless the stub can be easily separated from the hub - there's a lot on here about problems with separating the two parts- and I would see if I could have someone like CDD mate their new hubs to the Datsun shafts or someon else that could do it properly.
It may not be cost effective of course but just a thought.

Cheers

Mike

[Sheepdip]

Hi Mike, thanks for your reply, I had a search thru forum but nothing sprang out but a google search did note some issues, but the picture wouldn't load so none the wiser, but guessing breaking the taper can invisbly damage the shaft or hub? I've a couple of old shafts so thought I'd rebearing them and convert yokes to fit Datsun driveshafts - which can only be better.

Mine is a real clonk clonk when rocked off the ground, even my friendly MOT man would shake his head! I'm not sure if its the bearing going or the nuts just loosening - but seeing the 30 ton press in his workshop made me think I'll do something about it this time.

Do you know of any problems rebuilding?

Cheers

Paul

[mike@thenook]

Hi Paul

if you look under Technical guides/running gear/rear hub bearings theres a post from milo that gives a complete guide to doing the bearings but the main problem can be the amount of force required to split the shaft from the hub - it’s apparentły not unheard of for 15 tons to be needed which can have a ‘profound’ effect on the hub flange!
If you have spare shafts etc then even if you bend the flange you can get replacements I believe.
Not sure where you are (I’m near Brentwood Essex) but I have a 10 ton press you’re welcome to use if you fancy tackling the job.

[Motorsport Micky]

These hubs are 40+ years old and are the equivalent of pensioners in human terms, and like pensioners...they are dying. (I'm one myself and saying it doesn't upset me).

These "Innsbruck" design trailing arms and hub/stub axles are shared with Triumph 2.5 and TRs (if not exactly the same dimensionally) so their weaknesses are well known. No shame in that, if you asked ANY of the design engineers of BMW,AUDI, etc etc if their hubs supplied would still be working after 40 years and unknown stresses and "kerb hopping" had occurred they would think you were mad.
In the TR Register we have owners who are past Concorde BAE engineers whose past 30 years were spent checking them in "Non Destructive Testing" looking for cracks, who now scratch their head when trying to define how they could test their own IRS rear hubs so they and their families can be safe, it can't be done.
When these hubs were on cars then regarded as current in the 70s and 80s the dealer workshops were equipped with the correct Churchill tooling to allow the hubs to be safely split without undue stresses for renovation and new bearing fitment, and of course the hubs and stub axles were mere whippersnappers only being 10 or so years old and still with a future life. However another 30 + years further on restricted access hides the stressed areas around stub axles and the hubs themselves so that hubs which look wholesome but have suffered from the application of "30 ton presses" to be stripped down when rebuilt often then fail in use, and a rear hub or stub axle failing is a very serious occurrence...we do have instances of inversion happening on TRs.
As always there is much discussion between owners as to which is the best way forward, there are various CV driveshafts available which now offer alternatives to the very good quality Datsun CV driveshafts, and whether using any of those, is a choice for yourself. However no matter what driveshaft configuration you go with I'd urge you to fit new rear hubs complete to avoid the problems outlined here, maybe these were the pictures of Stag hubs you were unable to load.

Stag Hub failure.jpg

and this one


Stag Hub failure 2.jpg


I understnd both these hubs were are pair which had been reconditioned by a specialist and then retailed to a Stag owner, and both failed within 18 months (not many miles for Stag usage.)

Micky

[Phil S]

when I got my cat I was aware that one hub/bearing was shot by the 1/2 play the wheel gave.
stronger replacements were a must in my opinion, along with CV driveshafts.
I have now gone for the stronger front stub axles as well.
my take is to do it once and do it right

[mike@thenook]

Thanks for that Micky - I was trying to find your post for Paul but couldn't!

[Sheepdip]

Thanks for replies guysand your offer Mike - those photos are gruesome, can't quite see the second one but looks like the hub parted and guess wheel came off? I'd also read somewhere that the hub can crack along key. So heating etc doesn't help?

The suppliers must have same replacement issue tho? I'd happily fit uprated ones but the cost puts me off, maybe S/H are next best and forget the Datsun shafts.

Cheers

Paul

[Sheepdip]

...apologies also just read after the photo - so these were recons, although would have thought they'd fail quicker than that if faulty.

[Motorsport Micky]

...apologies also just read after the photo - so these were recons, although would have thought they'd fail quicker than that if faulty.

That's the trouble, nobody can tell and even crack testing experts can't gain access to the areas which are high stressed because stripping the hubs down causes even more stress which very probably is the straw which breaks the camels back. The faults here are indicative of stress...the material has been taken to it's elastic limit so many times the life has been leeched out of it, just as we wiggle a piece of metal back and forth eventually it reaches it's limit.

"(not many miles for Stag usage.)" ...typically how many miles will a classic car be used every year...many do less than 500, a few runs to the pub, a weekend away poodling along at 50mph, no surprise that failures are varied and spread, but the limit will be reached eventually. I understand that now some retailers won't offer to recondition hubs for sale.

As for cost it varies, but for an example a pair of complete new CDD hubs complete with uprated stub axles and quality bearings and attached to CV driveshafts (so no sticking or the "twitch") are available for around the £900 mark. There are other examples available from other suppliers so a little research and feed back reading will serve you well and supply a variety of costs. If you decide to buy just the hubs new at least that's the items which are problematical, even matched up your old driveshafts (this would need checking) it would give you the safe option. Lose a driveshaft and the car stops, lose a hub or stub axle and you will lose a wheel and with that maybe a great deal more.

Micky

[Sheepdip]

Thanks Micky, I obviously need to look into it further, I tend to do a lot more miles and don't stint the speed, S/H might be possibility to keep me on teh road, would just be nice to use the datsun shafts. I read somewhere that bad bearings are a problem too, could this not be a factor?

Paulo

[Motorsport Micky]

Thanks Micky, I obviously need to look into it further, I tend to do a lot more miles and don't stint the speed, S/H might be possibility to keep me on teh road, would just be nice to use the datsun shafts. I read somewhere that bad bearings are a problem too, could this not be a factor?

Paulo

Hi Paulo,

The Datsun driveshafts are unobtainium these days, about 2 years ago I found maybe the last pair in the UK after about 6 months of beating the bushes and then thought about everything we've posted above about wearing bearings and hubs which are 40 years old and chickened out of it. I passed on the Datsun contact to another Stag owner after working out that converting the yokes, using the same hubs and buying the driveshafts would have put me 70% of the way towards buying a pair of CDD driveshafts but they are complete with new hubs which are uprated with new quality bearings and stub axles.

I believe the driveshafts on Nissan 240 are similar but again broadly unavailable in the UK but I found some on e bay from the US but the auctions when watched were finishing at about £200 plus Customs and VAT and packaging which I got up to about £400 and then into modifying the yokes as on the Datsuns bringing them up to about the same costing but you still have your own used hubs which may or not be ok.

No brainer...go new.

Micky