Chipped Front Wheel Bearing

[Allchin]

I have just inspected all the wheel bearings and re packed them with grease. The only one that needed to be replaced was the offside front. This is the only wheel I had to re tighten the lock nut during our South American 85k mile trip . Since tightening, I had done another 20-30k miles with no noticeable problem! The make were Koyo but were not bought from Toyota.




Stephen

 

[clivehorridge]

That's amazing, the whole bearing looks shot to pieces when you look at the state of the rollers, but it still performed well

I was under the impression that Toyota used Koyo bearings, am I wrong?

 

[chapel gate]

You are right clive, koyo and timken.

 

[StarCruiser]

Looks like a testament to Koyo bearings that after such damage the bearing continued to give good service for another 30k. That looks like contamination damage to me, unless it was damaged on installation.

 

[clivehorridge]

Looks like a testament to Koyo bearings that after such damage the bearing continued to give good service for another 30k. That looks like contamination damage to me, unless it was damaged on installation.

For sure those rollers have been riding on something other than grease and the outer race, some sand and maybe rust in there. Or as Rich says, shards of steel, if that chip was a heavy handed way of assembly, in the first place.

Hats off to Toyo in any event.

 

[Allchin]

Actually, thinking about it, I think this might be original as all the others are now SKF and are still ok. I think the most likeliest reason was due to being caught out and unable to miss a pothole or 'private' sleeping policeman. In Central America a lot of these countries have sleeping policeman (Topes) but also 'private' ones, these can be any where, on bends in the country, in the shadows of a tree.

From the Russian trip 35K miles ALL of the dust seal were totally trashed, as they where after the saharan trips 5k.

 

[Dave2000]

That damage is more likely done during the installation, the hardened bearing race may have got jammed on the spindle, then some tightening of the large nut forced it to go 'square' on the shaft. Or an alternative is something hard (grit, swarf) got trapped between the bearing race and shoulder on the spindle, again tightening against it may cause it to chip.

regards

Dave

 

[Allchin]

the hardened bearing race may have got jammed on the spindle, then some tightening of the large nut forced it to go 'square' on the shaft.

regards

Dave

The bearings are a hand push fit and I use bearing lock to reduce the chance of the race spinning on the spindle. The first time I removed the bearings I noticed that had happened and around 1-2" has been worn from the bottom side of the spindle. I am pretty sure that no swarf or grit was the cause as I completely clean the hub and re-assembled in a clean environment. My thoughts are that when the wheel was tightened for the second time during the trip I may have left too much pre-load and that led to the failure, or maybe it was down to fatigue as I think this set of bearings where the last of the originals and for the last 120k miles have suffered some of the worlds roughest roads.

Stephen

 

[Dave2000]

Using thread lock is not correct in this application, you create a number of problems IMO. The first, thread lock prevents heat transfer from the bearing race to the spindle, often not thought about but does indeed happen, in particular when the going gets tough. The second is that you tighten the bearings and then back off and set the pre-load but, as per you observations with the worn spindle, you could actually be locking the inner race at an 'unnatural' position on the spindle, and of course finally, damage will happen somewhere trying to get the thread locked inner race off the spindle at later date, this often involves using a grinder as the metal is too hard to saw.

regards

Dave

 

[Allchin]

Using thread lock is not correct in this application Dave

I would agree if I was using thread lock but I was using a bearing lock which is designed for this particular situation. It may be more difficult as it could damage the dust seal on the inside if the bearing 'sticks' too well when removing, though I always change the dust seal when rebuilding. Maybe the next time I will change the spindle's.

The second is that you tighten the bearings and then back off and set the pre-load but, as per you observations with the worn spindle Dave

When you first torque up the bearings it pushes the inner bearing tight against the shoulder of the spindle and the pre-load should be enough keep it square against the shoulder whilst the bearing lock sets.

I will report back when I next remove the hub for re-greasing the bearings and if was a mistake in using sealant, we will see.

Stephen