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Road Ruler · 09-14-2002, 03:59 PM

Hello folks

I am curious as to what temperature many of you have felt on the wheel bearing caps after coming off a highway run. How hot can they get before alarm bells start ringing????

Thnxs in advance for any info.

john hd · 09-14-2002, 04:48 PM

i was always told that warm is o.k., as long as you can keep your hand on it.

if they get to the point where a bearing is too hot to touch then you are in trouble.

i always check mine every time i stop. along with the connections behind the truck. kind of a "walk around" just to make sure every thing is in order.

it could be that some of the heat you are noticing is actually from the brakes. on my wood hauling trailer with no brakes the hubs get only very slightly warm, even with a large load.(4-5k on one axle)

i think it would be also safe to say that your hubs should be no hotter than your tires after a high speed run.

john

Inland RV Center, In · 09-14-2002, 04:48 PM

Wayne.
A rule of thumb temperature for a hub is not very hot. If you can hold your hand on the hub, your OK. If not, then it's too hot. The hotter the hub becomes, the more likely the grease will leak out through the grease seal.
Hubs normally get too hot, when the bearing preload is excessive. A cold hub must have a very slight amount of play. You can check that by raising a wheel and grabbing both sides of the tire. Try to rock it back and forth. No movement indicates that the bearing retainer nut needs to be backed off, a notch or two, or until a slight movement is felt.

Andy
inlandrv.com
airstreamparts.com

mtbob · 09-19-2002, 03:17 PM

I believe a bearing preload should be applied of approx 50 ft lbs before backing the locknut out to the first cotterpin hole should be just about right.

Pick · 09-19-2002, 06:40 PM

Why is it that people with campers are so paranoid about wheel bearings? I have had I don't know how many trailers in my lifetime. Horse trailers, water trailers, equipment trailers, you name it. I've only done the bearings in one or two trailers, one was a boat trailer, that went in the water, and the other one I did, just to have something to do one winter weekend. After I pulled it apart I realized it did not need to be done. All of my trailers have seen heavy duty service. I say if you pull the cap off and there is grease in there, and no water or corrosion, let it be. Now that I have said that, watch me burn one up this weekend.
Sock it to me!

john hd · 09-19-2002, 07:23 PM

i don't think i'm paranoid about it. but the loss of a wheel on the trailer is not my idea of a vacation.

not to mention all the sheet metal that would need to get fixed! (the roof comes to mind)

john

Pick · 09-19-2002, 08:36 PM

People on this board are a "cut above the rest" when it comes to mechanical repair. Don't see any Jayco or Fleetwood restoration forums. Other RV boards seem to really be concerned with wheel bearing repacking. Yes, I am concerned with mine, and I do check hub temps on trips.

Dbraw · 09-20-2002, 05:31 AM

On our 1971 Safari, which has two axles, the rear two hubs seem to get warmer than the two front ones after 50 or 60 miles. However, not hot enough that I can't hold on to the hub. Do the rear brakes work harder? Do I have the brakes adjusted correctly? Any advice would be appreciated.
Dan

Inland RV Center, In · 09-20-2002, 12:53 PM

Pick and Dan.
Bearings should be packed on an Airstream trailer, once a year or every 10,000 miles. That is being "safe." Assuming the bearings are OK and that there is adequate grease, is not acceptable, when safety is considered.
If someone wants to live on the edge, that is certainly their choice.

Dan, your rear hubs quite well have the bearing retainer nuts a little too tight. Application of brakes, normally, unless badly misadjusted, would not cause one hub to be warmer then another.

Andy
inlandrv.com
airstreamparts.com

john hd · 09-20-2002, 05:46 PM

i'd have to agree with andy, the other positive to pulling your hubs once a year is that you can visually inspect the brake linings magnets and springs.

we have a 30 foot wells cargo car hauler that had one hub that was running hotter than the other three, when i pulled the hubs i found a broken brake spring. the shoes were riding on the drum causing the extra heat. the trailer was one year old.

would that have caused a failure of the hub? i don't know. but 3.00 worth of springs from napa probally saved hundreds in repairs. plus a delay in getting to where i wanted to go.

i guess it comes down to how much you are willing to risk, sitting on the side of a freeway with axle problems exposes you to all kinds of unseen dangers. from the semi that cant stop in time to the stranger who stops to "help".

john

Road Ruler · 09-24-2002, 06:49 AM

Some very good info from many of you.

I do follow the manuals directions as far as wheel bearings are concerned.
I know of a 72 Argosy, owner ( 22 ft.) that he bought new. He got many years out of his bearings without touching them. His lesson was learned the hard way. After pulling in for fuel and walking around the trailer he was in shock to see his curb side rear tire, wheel, hub, backing plate, bearing, assembly and a lot of sheet metal was "gone"!!!! The bearing had seized and the axle snapped off. Over $2,000 dollars in parts and labor to make the trailer roadworthy and more bucks to repair the sheet metal later.

I also got a good tip from an RV dealer. Because A/S wheels and tires are big and heavy they remove the tire, wheel assembly first. Then remove the brake drum. This reduces the risk of damaging the grease seal. On my Safari one seal was damaged when the previous owner installed the drum.

53flyingcloud · 09-24-2002, 07:16 AM

From day one, I've had my wheel bearing repacked. Check the temp of the hubs as well as the rims whenever I stop. Always~
This is my third year with my current A/S and, it's been repacked twice.(This summer was the most recent). My own policy is to repack the wheel bearings every other yr or after 7k miles.
Last year was the first time I really took it out for an extended trip. I might add that, I average better than 7k miles a year towing. This may seem abit too much but, I'd rather do this then be stuck somewhere with major breakdown/ problems.
Question for Andy:
Is there an easier way to do this??
"like a grease fitting."
If so, how does one go about getting it retrofitted??

Inland RV Center, In · 09-24-2002, 09:47 AM

Bad idea.

Forcing grease into the bearings will also force it out of the grease seals!!!

Where??

Onto the brakes.

Some things we still must do "the old fashion way."

Packing bearings is one of them.

Also, it is fool hardy to reuse grease seals. Yes you can save a few dollars, but only at the risk of a major accident!!!

But, some owners like to lean way over the edge.

Andy
inlandrv.com
airstreamparts.com

53flyingcloud · 09-24-2002, 10:44 AM

Andy,
Thanks for that 'insight'..
I never thought abt the grease getting out onto the brakes, etc. I assumed that with the repacking kit that, the seal is/has been replaced. I'll be sure to watch out for that too.
Again, you're right~! The old fashion way is BEST..
ciao

DanLyle · 10-14-2002, 10:22 PM

We were out this weekend and I did the "walk-around" at one gas stop. Sure enough, one bearing was HOT, the other fine. Right then and there, I pulled out of the way and dug in to inspect the cause. Bearing was starting to fail. Was able to re-pack it and limp home (with frequent checks). Need new bearing though, because I waited too long to re-pack them.

Pahaska · 10-15-2002, 06:31 AM

towner

Dexter makes axles with internal passages and grease fittings. I had one of these axles on my last trailer (a TrailManor). There is a fitting in the center of the hob and an internal passage to the rear bearing. You jack up the wheel and pump in grease while turning the wheel until grease fills the cavity and pushes out through the front bearing. You then wipe off the excess at the hub. The result is a hub packed solid with grease. There is a rubber cap on the hub so that internal pressures won't push grease through the seals.

The first thing I noticed was that as soon as the hub was entirely filled with grease, the hub temperature went up quite a bit because of the drag of all the extra grease. The hub never got too hot to lay a hand on, but all that heat has to come from added friction. I figured I was paying with extra gas for the convenience of not repacking the hubs in the old way.

I'm just as glad to have the old type of hubs on the A/S. I'll repack them once a season.

68 Suburban · 10-15-2002, 08:56 AM

When you clean the bearings, what do you actually clean them with.

Pahaska · 10-15-2002, 01:01 PM

I use mineral spirits and make sure that they are completely blown dry with compressed air before repacking.

john hd · 10-15-2002, 07:26 PM

i use kerosene in a small parts washer that is used for nothing else to avoid contamination. wheel bearings only. back before that i used kero in a coffee can then blew them out with compressed air, both ways worked fine.

john

Road Ruler · 10-15-2002, 07:38 PM

Tip
For years I would clean the bearings with Dunk and rinse with water, following the directions. Then I would slip the bearings on a couple fingers and blow the bearings with an air gun. The bearing would spin up very fast and dry completely in seconds.
My retired engineering buddy saw me do this once and said that letting them rev up dry was not wise as it could chip a bearing.
I am more careful now that I know.