10 replies to this topic

[1314cc]

just wondered if anyone has used the diff bearings that so say dont need pre loading with shims. Minimise sell them as well as other traders.
Im guessing stick to what's worked for many years!
eBay 184014696091

Edited by 1314cc, 27 January 2020 - 05:12 PM.

[DeadSquare]

Having taken some pretty floppy bearings out of diffs, I recon that as long as the bearings do not have more than the factory recommended preload, you will probably be OK.

[GraemeC]

Erm.... they all need pre-load.
Or at least the two most commonly available ones (thrust and non-thrust type) do, just different amounts.

[greenwheels]

A bearing by definition needs to fit, i.e. the bearing running faces/balls need to be located on the running face. If they are set up loose, i.e. with a gap between the balls and the track then it will 'hammer' itself looser. Hence the need for preload to locate the running faces to each other.

[Spider]

There was 2 types fitted by the factory - 'Thrust' and ordinary Ball Types.

 

The Ordinary Ball Types need 0.001 - 0.002 Preload.

 

The Thrust type need 0,004".

[Rorf]

If no preload, or a gap between outer bearing and side plates then the whole diff unit will end up sliding from side to side in the diff casing with concomitant damage to the diff cover and gearbox housing and strange antics under acceleration. 

[retired]

You are all assuming it's one of the standard type(s) of angular contact bearing - which DO need pre-load.

 

That eBay link, if you look at the picture is for an RSL11 basic deep groove standard ball bearing.

 

Not an angular contact bearing.

 

As such, it doesn't need pre-load, but neither will it take much side load compared to an angular contact bearing.

 

It's basically a seriously bad idea but, technically, what they say is correct, no pre-load required on that type of bearing.

 

Without shims, they will just slide from side to side between acceleration and deceleration so it's a gamble whether the bearings fail first (as they aren't intended for any significant side load) or the aluminium of the diff housing is just worn away and they spin in the housing. 

[1314cc]

Already ordered original type. I did contact minimine and they did say it's not an angular bearing.
There's quite a few mini traders selling this different type of bearing, even minisport. Minispares sell the original ones for £30

Edited by 1314cc, 28 January 2020 - 12:39 PM.

[unburntfuelinthemorning]

just wondered if anyone has used the diff bearings that so say dont need pre loading with shims. Minimise sell them as well as other traders.
Im guessing stick to what's worked for many years!
eBay 184014696091

The description on ebay states "Diff' bearings can become noisy through lack of oil when the oil galleries become blocked and very often require replacement.".

 

Am I missing something here?  Aren't they lubricated by half sitting in engine oil all the time?

 

[Spider]

You are all assuming it's one of the standard type(s) of angular contact bearing - which DO need pre-load.

 

That eBay link, if you look at the picture is for an RSL11 basic deep groove standard ball bearing.

 

Not an angular contact bearing.

 

As such, it doesn't need pre-load, but neither will it take much side load compared to an angular contact bearing.

 

It's basically a seriously bad idea but, technically, what they say is correct, no pre-load required on that type of bearing.

 

Without shims, they will just slide from side to side between acceleration and deceleration so it's a gamble whether the bearings fail first (as they aren't intended for any significant side load) or the aluminium of the diff housing is just worn away and they spin in the housing. 

 

I've been using RLS11 type Bearings for longer than I care to remember. While used under their own Part Number, they were factory fitted at various times.

 

'Ordinary' Ball Race type Bearings, like these, while not Thrust Bearings will take some Thrust and are designed to do so.

 

Here's a bit of info from NSK Bearings;-

 

 

You'll also find the top line Racers use RLS11 Bearings as when fitted, they have less drag.

 

The Preload is not only to stop the Diff assembly drifting in an Axial Direction but also as there's always some play in all Bearing Assemblies, it's to remove that. The Gears are (usually) Helical Cut and so from Drive to Over-run tends to twist also. On top of this is the variable loads from the various angles of the Drive Shafts.

 

Preloading also helps with these issues.

 

 

just wondered if anyone has used the diff bearings that so say dont need pre loading with shims. Minimise sell them as well as other traders.
Im guessing stick to what's worked for many years!
eBay 184014696091

The description on ebay states "Diff' bearings can become noisy through lack of oil when the oil galleries become blocked and very often require replacement.".

 

Am I missing something here?  Aren't they lubricated by half sitting in engine oil all the time?

 

 

Well,,,,, it is an ebay advert.

[no66]

But the proper bearing shimmed up is probably better for a road car due to this part hardly ever been serviced? There again a regular RLS11 is probably more than good enough. 

A race car has realtivly short use before service get checked faily often.  

Hmmm, I work in the bearing industry, RLS 11 ceramics?