Just had both my front wheel bearings practically explodeon my truck. The funny thing is that i just replaced my left side 4000 miles ago. What's the average life span of wheel bearings and what could cause them to go so fast?

 

you lifted or bigger tires?

that will cause it i replaced mine twice with having 33s and 37s on the truck

 

Did you pack them with grease? It might sound dumb, but I've seen it before. Guys thought that they were just "put in there". LOL

 

I go through wheel bearings like nothing it seems like. Already replaced mine twice as well.

 

Many people shortcut and do not replace the outer races when changing bearings.
Overtightening the spindle nut.
Using chassis grease instead of wheel bearing grease.
Chinese aftermarket parts.

 

I hear you on that. When I did front brakes, I called ahead and said I wanted calipers, pads, rotors, and new inner/outer bearings with seals. And to get a bucket of the appropriate grease for the bearings. I got the box, paid and got home, did it all. A week later, bearings on both sides were shot. The grease which was yellow, was now black and smelt like a burnt frying pan.

I got some lucas x-heavy duty bearing grease, it still green after 10k. Don't skimp on the grease!

 

I got ford/licoln/mercury specd greese and I've put a good 20k on my bearings.

 

Races were replaced, bearings from good source and the correct grease was used. The spindle nut is something I may have to look into. But I believe that was tightened to spec. Not sure of what ft lbs that was.

I am not lifted and only have 31's" on instead of the stock 29.5"

 

there is no spec on spindle nuts. You tighten until there is no wabble and then a quarter turn or something like that. Look it up in the haynes manual. If it is over tightened the bearing will not spin as freely and will over heat causing failure. If it is under tightened the bearing will have too much play and it will cause excessive wear and forces from vectors that the bearing was never intended to handle and it will fail.

 

This is what my ford manual says: