Wheel bearings
What is so different with RV wheel bearings that they have to be packed at least every year or two. My truck and car does not require this yearly maintenance, why does the RV axles??
Forum Discussion
61 Replies
JJBIRISH wrote:
wilber1 wrote:
CKNSLS wrote:
wilber1 wrote:
MTPockets1 wrote:
CKNSLS wrote:
. If & when your IR gun detects an overheating status, the bearing raceways are already damaged. That's what is creating the heat.
The once a year repack is old school thinking that permeates this forum. Check temps with the $25.00 IR gun from Harbor Freight at every stop and go from there!
Yup, heat is the result of a failure, not a warning of an impending failure.
OK-if your bearing fails it will overheat as well. Not sure of your point.
Checking the temperature just tells you if a bearing has already failed, not if it is going to fail.
Somehow this seems wrong…
Explain how that happens????
At what temperature would it go from impending failure to already failed???
So you are saying that a bearing temps can’t fluctuate due to load or even just due to heavy traffic and heavy brake use…???
What temp is good and what temp is failed???
Type of grease has nothing to do with it???
What about ambient temps???
How about speed???
Heat coming from brakes is self explanatory. Extra heat coming from load or speed is generated by the tires. If you are reading excessive heat because of a bearing, it is already junk.- I not only check hub temps. I take a reading on the outside of the bearing housing. Hub temps drop very quickly after stopping but the outside of the bearing housing next to where the inside of the rim surrounds the bearing housing, IMO, gives a better shot of bearing temps.
- The hub temperature will definitely fluctuate with brake use.
wilber1 wrote:
CKNSLS wrote:
wilber1 wrote:
MTPockets1 wrote:
CKNSLS wrote:
. If & when your IR gun detects an overheating status, the bearing raceways are already damaged. That's what is creating the heat.
The once a year repack is old school thinking that permeates this forum. Check temps with the $25.00 IR gun from Harbor Freight at every stop and go from there!
Yup, heat is the result of a failure, not a warning of an impending failure.
OK-if your bearing fails it will overheat as well. Not sure of your point.
Checking the temperature just tells you if a bearing has already failed, not if it is going to fail.
Somehow this seems wrong…
Explain how that happens????
At what temperature would it go from impending failure to already failed???
So you are saying that a bearing temps can’t fluctuate due to load or even just due to heavy traffic and heavy brake use…???
What temp is good and what temp is failed???
Type of grease has nothing to do with it???
What about ambient temps???
How about speed???super_camper wrote:
smkettner wrote:
The first repack is important to verify the factory build.
Once you know they are assembled correctly you can extend the service IMO.
This is good advice. The right wheel almost came completely off our brand new Master Tow dolly. They failed to grease it at the factory.
I am sure that can happen, but in my case I purchased a new fifth wheel from a dealer 1600 miles from home, and went and picked it up, and towed it back in two and half days ,so that 12K trailer seen a lot of miles per day with no problems with bearings or overheating. Second long trip was over 5K miles still no issues, and now the trailer will be six years old next month, and the bearings have never been touched, and no real plans to do so. Pretty much proven that they came from the factory properly packed. So I guess it's your call if you want to tear down a new trailer or not, I chose not to. IMO there is no need to verify factory build . Sure there is always a chance that anything can wrong from the factory, but I am not going to tear it down to find out .smkettner wrote:
The first repack is important to verify the factory build.
Once you know they are assembled correctly you can extend the service IMO.
This is good advice. The right wheel almost came completely off our brand new Master Tow dolly. They failed to grease it at the factory.jfkmk wrote:
Doing pm is good, but sometimes it fails anyway. I had it happen to me with a 3 year/150k mile warranty on a new torque convertor after 2k miles. I was 1400 miles from home when it happened in no-where Montana. Made for a bad two days. JMHO.
Packing the bearings is so incredibly easy that I do it yearly. I go through absolutely everything every spring and have the confidence all is well throughout the camping season. In my opinion, it is pretty cheap insurance to ensure I have a happy and stress free season.- For sealed cartridge bearings on a TT, check out Dexter Nerver-Lube system.
- On the topic of automotive sealed bearing:
A bearing manufacturer rep for a company that makes sealed automotive bearings recently discussed them. He said that some time in the 90's the auto manufacturers specified that the bearings have very low rolling resistance. This resulted in a design that uses dual-row ball bearings instead of the traditional roller bearings. They did result in lower rolling resistance. However, ball bearings have a much smaller contact area (theoretically a point instead of a line) and therefore they wear out faster. The practical result of this is that most auto bearing assemblies only last about 100K miles.
I have replaced many bearing assemblies on my new cars (and on friend's cars) at just past 100K miles so this seems plausible.
He said that trucks still used roller bearings because of their durability and ability to handle the heavier weights.
Steve JJBIRISH wrote:
westend
I assume you are referring to the permanently sealed bearings used in the automotive industry today… my own experience with them is they are slightly more problematic than when they used standard bearings in the front and oil bath in the rear and generally grossly more expensive… I use permanently sealed bearings for cross country racing but with them you just replaced them before they go bad because they go from bad to ruined so quickly…
One problem with a trailer is there can be a wheel vibration or noise at speed and you will never hear it… chances are you can’t save it nor is it worth trying at that point, but it normally makes it to the garage instead of failing along the highway in the auto…
Regularly scheduled maintenance is the key for trailer bearings… the scheduled timing could effectively be quite long, or relatively short, depending on use… one’s own comfort level may be just as important…
Yes, I was referencing a modern sealed automotive axle bearing, commonly called a "cartridge bearing".
FWIW, when these sealed bearings first started being used in automotive applications, there were many, myself included, that thought they were of less quality and a poor design for the application. I think mechanics, in general, have a distaste for new things, preferring to use older designs they have serviced. I've since, changed my opinion. With material science advancement and proven design, a cartridge bearing is as good or better than it's open counterpart. We don't get them in trailers because of hub design and cost, IMO.
Yes, scheduled maintenance derived from use and possible environmental issues is the key to longevity. Observation is the most important skill to have.
BTW, if you travel through Wendover, NV, there was a filling station out there in the flats. My '47 Dodge that had a failed front bearing (welded the race onto the spindle) used to be right out in front by the sign.
