Greasing the wheel bearings:

[davidjsimons]

I know that many of you among this forum suggest greasing the wheel bearing with the wheel off of the ground while in rotation. What is the purpose for employing that method? Because I have read that so many times from veteran RV'rs among this group, that is how I've done it, but my question is why?

[hankpage]

I know that many of you among this forum suggest greasing the wheel bearing with the wheel off of the ground while in rotation. What is the purpose for employing that method? Because I have read that so many times from veteran RV'rs among this group, that is how I've done it, but my question is why?

Most "veterans" will say to remove the wheel and pack the bearings by hand. If you are not doing that and using the ez-lube fittings rotating the wheel allows the grease to "supposedly" get to all parts of the bearing and push out the old grease. If you are using the ez-lube you are not checking the condition of the bearings or the brakes which should be done at the same time. JM2¢, Hank

[davidjsimons]

Thanks Hank. I will get my bearings re packed or replaced at the end of this season. While I have greased my bearing using the ez-lube system, getting the wheel off of the ground has allowed me to at least check the bearings for any excessive play. I put over 12,000 miles on my camper last year and have ran over 3,000 so far this year. I've kept my bearings greased I suppose, with that mileage, would you recommend replacing them at the end of this season?

[hankpage]

I had my last trailer 12 years and my present one 7. I have never changed bearings, but I do clean, inspect, repack and replace seals every year. Now that I have ez-lube I will put a few pumps in while hubs are still warn from a long trip ... just because they are there. Maybe I am lucky but I have never had a bearing failure .... yet, so I don't plan on changing my routine just because someone says it's EZ. Just call me old fashion, Hank http://www.keystonerv.org/forums/picture.php?albumid=251&pictureid=1587

[JRTJH]

I agree. Wheel bearings on old cars (40's and 50's models) would go well over 50K miles before any problems with wear, provided the bearings and races were maintained properly. That included cleaning, packing and adjusting the tension regularly. Things have improved since then and on today's automobiles, it's not uncommon to go 100K or more with no wheel bearing problems.

Many of the RV bearing/race sets are made in China and are "supposedly" inferior, however the majority do quite well for years and years with minimal maintenance, even if it's just a couple of "quick pumps" with the EZ lube system.

If you're not having any problems, hubs are running about the same temp consistently (I check mine with a laser thermometer) then I'd just clean, inspect for wear, repack and replace the seals. There's no need to change them if there is no problem with them.

Just an example. The hubs on my Cougar usually run about 110 on the shady side and 120 on the sunny side. My F250 runs about 150 on the shady side and about 165 on the sunny side. I think part of that is drum brakes vs disc brakes on the truck. But, as long as all the wheels on the trailer are about the same temp, I'm not concerned with one set of bearings "dragging" and getting scored. Temps indicate things are about the same on all wheels, and so long as there is no "significant rise in temp" there's really no need to worry about bearing issues.

[gearhead]

If you tear into your bearings be very observant. Look for anything other than shiny. Purple color on the race is usually a indication of high temps. Look for corrosion as well.
If I replace bearings, I use Timken brand. For all I know they may be made in China these days. It's been years since I replaced any bearings.
Industrial bearings are monitored by temp and vibration. Monitor the temps and keep your wheels/tires balanced is about all you can do.

[gearhead]

Here is a Kingsbury thrust bearing in a hydrogen compressor turning 12,000RPM. You don't want to see things like this: rotational scoring and coking. In service for 17 years until 3 weeks ago.