Timken Bearing Failure information

[Bill_Wolf]

My son, who works as a Global Supply Chain Manager at Timken Bearing, sent me this article that Timken authored and which recently appeared on the Machine Design.com website.

Some interesting fresh thoughts about what causes bearing failure.

He also sent Timken's bearing failure wall chart. Feel free to download both below.

Bill

http://www.cckw.org/pdf/timken_bearing_killers.pdf

http://www.cckw.org/pdf/timken_bearing_damage_chart.pdf

[Barry Churcher]

Thanks for that Bill. Very interesting.

[dr deuce]

One thing that they didn't mention is brinelling. That is when a bearing (ball is probably the worst) sits in the same place for a long period of time under load. The small contact point tends to harden and is prone to shattering when in use later on.

Brinelling typically results from a heavy or repeated impact load, either while stopped or during rotation. It can also occur from a heavy load remaining on the bearing for a length of time in a stopped position.

There is also false Brinelling

[mudflap]

Very interesting. Thanks for sharing this.

I especially liked the part about lubricant compatibility. I have had the debate for years with various mechanics concerning the correct way to repack bearings. I have always cleaned them with solvent and removed as much old grease as possible from the hub and other components before repacking. Many insist that just repacking the bearing with new grease is good enough - because, after all, grease is grease. (Not to mention that thoroughly cleaning the bearings also provides an opportunity to thoroughly inspect them.)

In addidtion to the above links, Mobil has more to say regarding comptability:

http://www.mobilindustrial.com/ind/engl ... bility.pdf

BTW, the second of Bill's links does have some information on brinneling and false brinneling.

Best Regards..

[Motto]

Yes brinelling is covered and is relevant to the G508. It's to be found in the upper and lower steering knuckle bearings, in the third axle oscillator bearings (I've seen the rollers embedded in the outer race to half its thickness) and in the banjo T/fer case hi range constant mesh gear which spends most of its time locked to the shaft and is supported on needle rollers.
These equate to applications where there is no spinning motion but at most only rocking back and forth.

David

[mudflap]

I'm still kinda new to these trucks, so you need to help me out...

What exactly are the "third axle oscillator bearings" ?

Thanks..

Best Regards...

[Motto]

Third axle, oscillator axle or trunnion shaft refers to the axle unit bolted to the frame that the rear suspension pivots on or from. The CCKW has the spring seats attached to each end mounted on tapered roller bearings.
It is not a good application of tapered rollers because the spring seats just rock back and forth slightly when the intermediate and rear axles move up and down in relation to each other. As stated, I have seen these bearings with the rollers embedded to a depth of half the thickness of the outer race or cup. Some truck makes with a similar suspension arrangement use bronze bushings in this location.

David

[mudflap]

Ahhh... Gotcha.. Thx...

Yes, I can see how this, and the other examples you mentioned, would be tough applications for roller bearings.

Best Regards...

[dr deuce]

The 4 ton WW2 Diamond-T uses a bushing