Rear hub bearing grinding on axle - See pictures

[TFN]

Good evening, an odd one for you.

The rear hub grease seal on my 79' Sprint failed so I removed the hub to replace both grease and oil seals. However, when I removed the hub I found the bearing cage had been rubbing on the axle to the point where the cage had nearly worn away and it has scored the edge of the axle - See pictures.

The issue appears to be the half-shaft moving too far into the axle - See picture. It is the nearside hub so on a right-hand bend it is pushing the bearing against the axle.

Adjusting the hub shims will not reduce inward movement of the half-shaft. The collar the bearing is pressed against is in the correct position (I have compared it to another half-shaft) and before removing the hub I checked the end float - It was 0.2mm. Ideal is 0.1 to 0.15 but 0.2 is still within spec. There are no signs of bearing wear (smooth and not noisy) and the cup is smooth. It is the correct bearing - Confirmed by Timkin part number. There has been some muck in the grease at some point as I can see scoring but that shouldn't effect the movement of the half-shaft.

I thought there might be a thrust bearing or similar to limit half-shaft movement in the diff but there is nothing on the parts diagram.

Has anyone experienced this before as I can not see what is causing it. I cant believe the bearing was designed to make contact with the axle but it seems to be the only logical answer. Have I missed something obvious?

Any help will be gratefully received.

Gavin

[gmsclassics]

I had something similar about 15 years ago when I had an LSD 'professionally' fitted. After a lot of issues similar to those you describe I found out they had fitted ALL the shims (that set the end float to the half shafts) on one side rather than splitting the amount of shims equally on both sides. Overall end float was okay, but wasn't centralised as it should be. Took me ages to work out what was wrong. Might be worth a check. Obviously you'll need new bearings, seals etc.
Geoff

[TFN]

Good morning Geoff, thank you for the reply.

I have checked and there is one shim on either side of a similar thickness. When the half-shaft is pushed fully into the axle the collar that the bearing is pressed against is 4mm inside the axle - See picture. The shim on the other side is less that 0.5mm so removing it wouldn't give the movement required.

I have found a post that suggests there is a floating spacer that sits between the half-shafts in the diff but I can't see anything similar on my parts diagrams? Can anyone with knowledge of diffs confirm this?

I think I will have to drain the oil, strip down the other side and remove the diff cover to fully assess what is going on.

Frustratingly the car is too close to the garage wall to remove the other half-shaft so I will have to put it back together to move it to take it apart again!

If it wasn't a challenge, everyone would have one!

Gavin

[xvivalve]

I currently have a 'sniff' of some NOS rear Sprint bearings; should know more next week...

[soe8m]

There is a floating bush inbetween the halfshafts. There are more cars that have the sprint type salisbury rearaxle like old Volvo's and these have the same. You have to see both halfshafts and the floating bush as one length and the play adjusted by shims. When one side has more shims than the other does no harm. Volvo say's one side fit without shims and the other side adjust with shims.

Jeroen

[TFN]

Thanks Jeroen.

That makes sense of what is happening. I will strip down the other side and remove the diff cover to see if I can locate the issue. The movement is considerable, is it possible for the bush to wear significantly or the diff to be built without it?

In reply to Alun's post I have found a supplier of new Timken 2585/2523 bearings for £35 plus VAT. However my bearing cup is 2523S which triples the price! The supplier said the S denotes an extra process to the standard bearing (small runs so more money) but he didn't know what the process was. The dimensions of both are identical but the S is a few grammes heavier. Any ideas? The supplier is bearingbasement.com.

Gavin

[soe8m]

These can have some wear but that's very little and "shimable". Mm's movement isn't normal wear. It's easy to check if there's a bush when both halfshafts are out.

Jeroen

[TFN]

Thanks Jeroen. I'll post an update next week once I've had a chance to remove the other half-shaft. I've emailed Timken about the 'S' designation on the rear hub bearing cup so hopefully I'll have an answer to that too.

I've worked on most parts of a car before but never a diff - Too many special tools required! So I know what I'm looking for, is the bush shown in the parts diagram I posted earlier?

Gavin

[soe8m]

Thanks Jeroen. I'll post an update next week once I've had a chance to remove the other half-shaft. I've emailed Timken about the 'S' designation on the rear hub bearing cup so hopefully I'll have an answer to that too.

I've worked on most parts of a car before but never a diff - Too many special tools required! So I know what I'm looking for, is the bush shown in the parts diagram I posted earlier?

Gavin

[TFN]

Perfect, thank you.

[TFN]

A bit of an update. Having removed the other half-shaft it appears someone has ground about 2mm off the end! To make it worse the collar that the bearing sits against is 2mm further from the treaded end than the other shafts I have compared it to. This compounds the issue and effectively makes the combined lengths of the shafts and bush about 4mm too short. This may account for the contact between the bearing cage and the axle.

I have sourced a second-hand half-shaft and when fitted this gives clearance between the bearing cage and axle on both sides. I haven't had time to fit hubs and shim but it is looking hopeful. Fingers crossed.

Who grinds down a half-shaft? Muppet!

[TFN]

Just an update - I have fitted a replacement half-shaft, bearings/seals (both sides) and shimmed it to spec. I've only done a couple of hundred miles but all seems well. Thank you for the advice, I now know my way around a Dolomite axle!