Wheel Bearing Failure Causes

that's what I think is funny. years ago called local kw dealer asked what the torque spec is for the bearings would not tell me because they didn't want to be liable if it failed unless they did it themselves. that's when I started to learn myself.

 

We've had issues for years with this on my Truck. The mechanics have all been good trusted local guys. I changed the hubs about five years ago thinking that maybe it was machined wrong because it was chewing up outer wheel bearings once a year. The local shop warrantied the work but it not good for either of us. The spindles always look good and I've been so tempted to just change them. My dad made up a tool to press in the races thinking that the way the mechanics pound them in was getting them ####eyed. The longest they've ever lasted was 3 years? I do heavy work ( 140000 lbs)but nothing that other guys don't. Synthetic oil all that truck is greased and inspected every 6500 miles or once a month whichevers shorter. The last few years though it seems whenever I do brakes I end up having one or two bearings flaking. When we did the rear brakes we found one and ended up changing the hub because the new race just fell in! Getting old that's for sure.

 

Was wondering if your rims and tires different than the originals and making the outside bearing carry more load than the inside?

 

Shake my head wondering why they think using a torque wrench is beyond the ability of an owner operator. Try another dealer. Information should be shared, not hoarded.

On my dually dexter trailer hubs the info is available on their website. They say to spin the hub while torquing it to a specified preload amount (can't remember but it's something like 120-150 ft-lb). Then with the wheel stationary, loosen the nut, then turn by finger until it's tight, then backoff 1/4 turn and lock it in place.

They're all different, but they should share a safe and reliable procedure.

There's also 3 different ways to initially lubricate the bearings.

1) Grease - I used to do this and then let the 75W90 mix with it and displace the grease. Seemed to work fine, but the oil gets discolored from the grease. Always wondered too if the grease would initially block the 75W90 from completely filling the hub. So to be safe check hub level a lot after assembly and keep adding oil till it stabilizes.

2) Just put 75W90 on the bearings and race during assembly.

3) Put on a special bearing lubricant (can't remember what it's called) when assembling the bearings. Comes in a squeeze tube and is more compatible with 75W90. It allows the hub oil to mix freely once you fill the hub. This is the way I do it now.

 

The reason a hub gets loose retaining the bearing cup is the removal. You have to weld a bead around the cup and they will fall out, pounding them out and they stress the hub.
The proper way to set a wheel bearing is to tighten it up real tight and rotate it, back it off then tighten till it is just tight you want absolutely no slack and no preload. If you used a power washer to wash the hub you want to leave it so the tempature normalizes. A mercedies instructor he came to freightliner and had a long procedure to do it, I did it my way, he took a screw driver and moved the washer behind the nut, checked for slack and said it was right.
Checking wheel bearings is a part of the Government inspection in our area, you would be amazed at the number of wheel you find loose, or using the wire tie method to check the wheel seal you find leaking.
Just a thought!