[flybouy]

Gearhead I appreciate your industrial experience. I also have had a lot (20+ yrs) experience in that arena as well. When I was young I worked for an electrical firm that specialized in power transmission, computer/electromechanical controls etc. I've been in oil refineries, food processing plants, water treatment facilities, elevator towers, and many other large equipment facilities.

In my experience there were very, very few bearings on a "replacement schedule" however unless a sealed bearing was used there were definite "preventive maintenance" schedules that were followed.

In my experiences those bearings that were not sealed were greased or oiled on at regular intervals. Pillow block bearings on shafts would have a zerk fitting and some machinery would have a central lubricating system to carry grease, or oil
(more typical on bronze bearings where shaft runout is critical). Conical bearings commonly found in gearboxes, and roller bearings found in gearboxes and other power/transmission devices are typically lubricated by the oil in the gearbox. This is the only commonality I can think of between industrial and automotive uses. Rear axle bearings are typically lubricated by the oil in the rear axle. So enough on comparing horses and zebras.

There's a lot of rhetoric about why rv manufacturers use cheap China born bearings on this, and many other camping forums. Of course cost and profit is #1 by I think it goes deeper. My thoughts may be way off base but here they are. On this forum it appears that there are a high percentage of "full timers" and folks that travel thousands of miles yearly. I don't have any hard numbers but my guess is that statistically this is not the "norm" for travel trailers. When I walk around campgrounds I see mainly tags and dealer stickers from <50 miles away. When talking with fellow campers I typically hear "we like it here because it's close". Makes sense that the "weekend warriors" want to spend their limited time camping and not driving. I've passed a lot of storage lots full with RVs, and camped in many campgrounds with growing numbers of "seasonal sites".

Given the numbers of campers that move relatively short distances I can understand why a manufacturer wouldn't invest money in a suspension beyond "minimal" components as they aren't building a box trailer designed to be dragged a million + miles per year.

I have repacked more wheel bearings on the front of vehicles that I care to recount but here's the difference. From what I'm reading some folks think that the MAIN purpose is to replace the grease. Going back in time, cars and 2 wd trucks had drum brakes on all corners. The only way to inspect the shoes, springs, hydraulics is to remove the drum/hum from the spindle exposing the bearings in the hub and the grease in the hub and spindle to the brake dust and debris. After inspecting/replacing the brake components it's only prudent to clean everything and apply new grease.

The manufacturer is going to recommend a schedule for inspection by miles and time. They do not know haw many miles you will tow per year and I doubt most users don't unless they "think about it" and take a "guess". I've seen posts on this forum where failed brake parts are evident after very few miles. The only way to know is with a visual inspection. In my thinking a "yearly" inspection makes sense because "you don't know what you don't know".