proper maintenance of wheel hubs

do not let oil be too low

 

What kind of hubs? There are many types. If you have a cap with a sight glass, make sure the oil level is between "Add" and "Full". If it's a grease hub, or been converted to grease, follow manufactures recommendations. They will need to be checked and repacked at a certain interval. Unitized hubs require no maintenance other than checking them at the manufacturers recommended intervals. There are no serviceable parts in a unitized hub, you have to replace it when there's a bearing problem.

 

They are either unitized or grease packed. What you want to do is jack it up and spin the wheels, they should spin smoothly and quietly. Grab the top of the wheel and push in and pull out hard to check for excessive play in the bearings. A very small amount is normal.

If you hear a faint clicking noise in a grease hub from the bearings, they are long over due for repacking. The clicking noise comes from the bearing rollers as they roll over the top and drop down the other side. If you hear this pull the caps and you'll find that the grease is thrown out away from the bearings. You'll need to pull the hub and check/replace the bearings as needed.

If they're unitized and clicking, feel rough spinning or have too much end play, it's time to replace them. You cannot replace the bearings in a unitized hub, you need to replace the entire hub assembly.

 

Another question? What are the reassembly instructions?

I mean the torque to set bearings correctly?

Too tight and too loose is bad, so what do you mechanics use?

I also understand the liability and catastrophic results if installed incorrectly.

Thx

 

What hubs? A conventional oil or grease hub should be set to 0.001-0.005" end play, I shoot for 0.001"-0.002". Preset hubs (the ones with the spacer between the bearings) have the same end play, but the inner nut gets tightened to a high torque value (usually 300-350 ft/lbs). Once it's tight, you need to check for proper end play. A unitized will have a torque value, I've seen anywhere from 300-750 ft/lbs.

The first step is identifying the hubs. There are far too many to give more than general instructions.

 

Hello, They were on a 2006 Transcraft 48 Combo flatbed. I will post pics of bearing/race damage. We discovered it while changing brake shoes. The hub had so much play from wear. We immediately put it OOS till we could find parts and replace. Mechanic does it by "ear" so to speak. He has over 25 yrs experience and does excellent work. These were the original bearings by the way.

I did find some good info here.

Wheel end maintenance
Complete guide to trouble-free handling of bearings,
seals, hubcaps, lubricants and more
http://www.skf.com/binary/12-64875/457975.pdf

 

Here is damaged bearings. The whole bearing was like this. Ouch! Pitting really bad.



Hyatt HM218248 Made in China


Contaminated oil? Bad/subpar steel in bearing manufactoring?

 

Dont know about truck bearings, but several guys on a Harley forum have posted similar pics of Chinese made m/c wheel bearings that are badly pitted.
bearings were only a couple years old, mostly on rebuilt shovels and evos...
Replaced with Chinese, same thing again. Replaced with good US or good Japanese, no prob.
Just sayin.....
Mary