Thread: Rear Wheel bearing failure

Originally Posted by rory

Hi Guys,

I recently had my Salisbury diff (Defender110 2002) rebuild with a Truetrac center and Ashcroft HD Axles. I chose to convert the wheel bearings to oil fed, like so many other do and recommend. I also changed the stake nut and spacer to the double lock nut setup. New Timken bearings all round.

My problem is, the first test drive I did was 40km out of town and as I arrived my drivers side inner bearing overheated and collapsed, destroying the bearing, the stub axle, and the hub.

I was very careful with setting my preload on the bearings, I tried 4Nm and 10Nm, but in the end was happy with them nipped up finger tight. This was enough to remove any end float. I really don’t think this was the cause of failure.

I have been wondering if the inner bearing wasn’t getting enough oil, but lots of people on Aulro do this conversion and it’s not a problem. When I removed the hub, the oil was heavily contaminated from the destroyed bearing, so I guess there was enough oil flow. I definitely removed the stub axle seal, 100%. I also overfilled the diff to 3lt of oil, like others have done.

The only other thing it could be was, when I took my rotors into the brake specialist to have them skimmed on the lathe, the mechanic managed to burr one of the bearing cups when knocking the new ones in. It was rather small, and he assured me it would be fine, as the bearing rollers don’t make contact that far up.

Does anyone have any input and could help me understand what happened. I really don’t want to make the same mistake twice.
http://i1373.photobucket.com/albums/...ps96exun0z.jpg

Sure looks like a dry bearing in that pic. Or have you cleaned it up?

Hmm, did you do either of the following ?

Lightly grease the bearings on installation ?
This allows lubrication until the oil makes it's way to the inner race.

or

I used to overfill the diff and jack up alternate sides to get oil down the axle tubes before driving when doing a conversion.

Both work. It'd be nearly fifteen years on the old Deefer rear bearings now, over 200,000km and never adjusted.

Did you pack the bearings first with grease? Or did you hope that the oil was gonna do the job straight away?
Always, ppl, grease the bearings first...

Cheers Rod

Thanks for the responses guys.

The bearing in the photo is how it came out. Very dry.

I didn't pregrease, as I thought the oil was sufficient enough. I overfilled by jacking up the drivers side. So the passenger side would have been pre oiled. Unfortunately I didn't realise I needed to Jack the passenger side as well to lube the drivers hub, just assumed the oil would make its way in as soon as I started driving.

This time I will lightly pregrease.

Lesson learnt.

Originally Posted by rory

Thanks for the responses guys.

The bearing in the photo is how it came out. Very dry.

I didn't pregrease, as I thought the oil was sufficient enough. I overfilled by jacking up the drivers side. So the passenger side would have been pre oiled. Unfortunately I didn't realise I needed to Jack the passenger side as well to lube the drivers hub, just assumed the oil would make its way in as soon as I started driving.

This time I will lightly pregrease.

Lesson learnt.

Better check the other side also.

For sure, I will redo both sides. Although the passenger side had no heat in it when I pulled over, so I assume it was oiled correctly.

Wow that bearing is well and truly destroyed after a forty kay drive, did you hear any rumbles along the way?

Cheers, Mick.

Thanks for posting this Rory.
Definitely something that will catch others who are not aware of the necessary greasing, like me!