Rear hub bearings - fresh thinking or already been done?

[silverbullet]

More a subject for general Tech but when it comes to the rear hubs, syncro ones get a right hard time so let's start here. Clive kindly leant me a "suspect" hub ages ago for inspection and assessment but on the face of it there's nothing much wrong, which sewed the seed of this idea:
Why persist with the ball/roller bearing combination at all? VW only did it because it was quick and cheap to assemble and fitted the bill for a 1-ton commercial in the early 70's in the T2.
Why not evolve the concept to a pair of opposed taper roller bearings with a solid spacer and shimmed to set the preload? It would only be borrowing the idea from big "quality" vehicles with IRS of the same period like Jag XJ6's and Rover P6's, both of which used this bearing support method to good effect. Collapsible spacers were also tried later on but are not an option for offroading (cheaper and quicker assembly but shorter life, as the preload falls off with use)
Seems blindingly obvious to me but I may have missed something?
The hub nut will still need to be done up pretty tight but that's another argument entirely...

[Titus A Duxass]

Not got a syncro but would be interested in a 2wd version.
I've got a "spare" hub that needs new bearings.

[dash]

Do Syncro ones 'get a hard time' because of the loads, or because they get full of crap from going swimming?

[silverbullet]

Do Syncro ones 'get a hard time' because of the loads, or because they get full of crap from going swimming?

Mostly because the drivers push well beyond the original syncro design parameters

I think I smell an argument on the wind

PS I should have written "endfloat" not "preload" as the driveshafts are floating and not a suspension component.

[Aidan]

looks like a good idea, but given that the outer is a special I'd be suprised if you can find standard taper roller bearings in C3 grind that will fit and do the job, the outer is thicker than the standard bearing that diameter would be
a lot of the issue seems to be wear in the cast carriers where the inner seats, if that's ok then for £40 you can fit the Best Quality bearings and get many years out of them as it is
bearing carrier is same as on late type 2 and interestingly VW didn't change the bearings on the 16" even though they had to create a new casting so their stress analysis said they were man enough for the job, and they generally over engineered/specc'd everything by a bit


apart from the 3rd 4th synchro hub of course

[syncropaddy]

I don't see any need to change the type of bearing at all and some vans are still plodding on with 250,000 miles clocked up. Certainly the Syncro variant seems to take more of a pounding but if there is a 'fault' I would point to the casting that is the bearing carrier. If 'improvements' were to be found I think that a slight redesign in the carrier and to be manufactured in a quality steel able to withstand the rigors of Syncro life.

[Simon Baxter]

Syncro hubs, from my experience seem to go oval, getting bigger towards the top and bottom.
some are that slack that the bearing spins in the housing, it goes black and wrecks the housing more.
Not really a problem with the outer other than being a one off, originally made by torrington (part of timken) although recently some F coded INA bearings have been filtering though with the FAG kits we have.
I've not seen anyone else making this bearing other than the chocolate ones from GSF, which tend to collapse in less than 1000 miles, if your lucky.
As I've said before, I use plenty of bearing fit on the bearings and don't get any back even with reasonably worn hubs.
I did speak with the engineer that does all my machine work and he reconed the set up work to get the housing central to machine it to a bigger size would be a bit of a labour intensive task and probably not worth doing on cost grounds.
I have also seen one bearing housing that has been sleeved, the sleeve started to get squeezed out with the weight of the vehicle.
If you can find a cost effective way Ian of reworking the originals I'm all ears.
I did wonder about how much material could be added by zinc plating the housings? and if it would be enough to tighten the bearings up.

[silverbullet]

IME bearings can usually be bought in seperate halves as they have their own part number, so the inner and outer tracks can be specc'd to different duty/weight/diameters. Needs investigation.

Plating the carriers won't put enough metal where needed and since it's all zinc based (or nickel) so would be soft and move/flow in time. Back to square one.

Hard chroming of the bores with the attendant masking off etc. then jig grinding to restore the original limits would do it alright but would also be prohibitively expensive, even if batched up.

FWIW I had always thought that the bearing carrier was forged steel, not cast iron (there is a cropping line each side and no sign of casting risers having been trimmed off) Iron wouldn't be strong enough for the single lug/fin at the top, ever seen one snapped off? Bent, maybe.

There has to be a better way than "engineers filler" in the long run. Not that there's anything wrong with Loctite etc, it's good enough to hold railway carriage wheels onto the axles...

[toomanytoys]

Out of interest, how much are new carriers???

[Aidan]

no longer available from VW, maybe available from Classic

[silverbullet]

Holy thread resurrection Batman!!!!!!!!!

Neil dumped some exchanged hub units on me recently (including Rob's dead one), so I've had a delve into our SKF catalogues and there might just be a way of saving spoiled bearing units by converting to 1.375" bore bearings. The stub axles would need a very light grind on a cylindrical machine as there's only 0.003" to come off.
But...I don't have the lists for plain roller bearings in English sizes to hand.

If converting to Imperial double-opposed taper roller units then it looks possible to build a unit with higher overall load rating, but again there's a snag in that the outer 62mm bearing would need to be increased to ~65mm, so it has a lip to seat the outer race. It's not getting scary thin for a steel forging, but would need testing.

When the housings are basically unworn i.e. not ruined by a catastrophic failure, then retaining the 62/72 dia and 35 bore should still allow a double taper conversion.

Food for thought. Unless Classic now list the rear carrier, in which case it's all fluff.

[lloydy]

14" rear hubs are €362
Strangley 14" hubs for abs equipped vans are €201.75
Sadly 16" hubs are not available. Although mine are ok and grumble free at the moment, this time next week I'll know how good/bad they are.....

[silverbullet]

360 Euro? What a liberty. I reckon I could do souped-up ones for a lot less.

Before anyone asks about billet steel ones, the blanks alone would be about £60 each and who knows how many hours carving to get them into shape.
But then they could have dedicated disc mounts

Back to work...

[Titus A Duxass]

Ian- "billet steel" - i love it when you talk dirty.

[syncropatrick]

Sadly 16" hubs are not available. Although mine are ok and grumble free at the moment, this time next week I'll know how good/bad they are.....

Can we scavenge LTs for these, as the rear brakes are off LTs?