In the 20 years I have wrenched on trucks (class 8 that is), my experience has been improper bearing seating and preload is a huge contributor to seal/bearing failure. Too much play allows the hub to walk around, too little play allows the bearings to get hot no matter if they are grease packed or oil bath. I have watched guys use a hammer and punch to seat the bearings, then back off the nut and tighten it finger tight and call it good. Drives me crazy when they do that. I use a torque wrench to seat the bearings while rotating the hub. Then back off the nut per manufacturers directions then set end play per their instructions with a torque wrench unless they specifically state a degree of turn to the tighten side. A former employer use to get the nut as tight as he could with a socket and breaker bar, back off the nut until loose, then tighten 1/3 - 1/4 of a turn to the tighten side and call it good. Yes, he had seal failures, frequently. I started using my torque wrench, because he didn't have one, and seal failures went to zero. He lost a trailer because of his "old" ways, it burned it to the ground because of a bearing fire that was packed with grease. I mention this because you never said how you would seat and preload your bearings on your equipment. On my personal stuff, a 5th wheel toy hauler, 20 foot utility trailer and a 10 ft utility trailer, I pull them apart once per year, clean, grease, install new seals and reassemble. Never had a bearing/seal failure on any of my stuff. I believe the largest contributor to zero failures is taking the time to seat and preload the bearings to manufacturer specs. Bearing and seal quality makes a difference. Timken bearings and seals from Timken, SKF, Scott (owned by SKF) or Stemco are all great seals. Made in China can leave you stranded. Good luck and stay safe out there.
I've had 3 trailers my 2 with oil one with Greece haven't had any trouble with either one but I am very careful about the way I turn my trailer trying not to put pressure on those seals
That's a good point! Do you think it's turning sharp in reverse and dragging tires that cause leak's? We are always trying to figure the root cause. Some drivers have more trouble than others. That could be why.
Do you only use trailer bearings manufactured in the USA in your fleet or have you not seen much difference in the longevity with foreign manufactured bearings?
