Dan,
It is recommended that trailer wheel bearings be repacked every 10,000 miles or
so (or annually, whichever comes first). One big reason to repack the bearings so
often is because of their load, which is quite a bit higher than a car has. Even
my little GlobeTrotter weighs over 3000#, and will probably hit nearly 4000# when
it's ready to roll. All of that is on only 2 wheels, not 4 as on a car.

Another thing is that it's not uncommon for a trailer to sit for long periods,
allowing moisture to creep into the bearings and cause rust; a car is driven
nearly daily and doesn't get a chance for the bearings to rust. A rusty bearing
will fail, and a failed bearing could be very problematic.

I'll give you an example: my VW Jetta has a rear axle that is quite similar to an
A/S axle, drum brakes and tapered roller bearings. Although I forget what the
book says, I try to repack those bearings every couple of years or 50,000 miles.
Like the A/S bearings, these are somewhat overloaded in my opinion, so it's
important to keep them lubricated and adjusted. Not long ago, I had a bearing
sieze, due entirely to my neglect. Luckily enough, I was in a small town, near my
folks' house and was able to get to their driveway; I had gotten to their house
via the Ohio Turnpike and was heading in that direction when the bearing gave it
up. A normal bearing R&R takes maybe 20 minutes, but this one took 2 or 3 hours
of fooling around because the inner race had spun on the spindle, galling things
and siezing it in place. Not having the proper tools at this location (things
like a die grinder) made it all the more difficult, but I was still very lucky.
Had it failed 10 miles sooner or 10 miles later, it could have twisted off the
spindle or at LEAST required the car to be towed. I can't imagine that costing
less than $100.00.

So, it isn't just "how long will things go without maintenance?", but "what are
the consequences of neglect?" A vacation could easily be ruined (or much worse)
by lack of maintenance of your wheel bearings. If you have been driving the
Interstates for many years, you've no doubt seen trailers sitting alongside the
road with a wheel missing. That means that it wasn't a simple flat tire. Boat
trailers are particularly susceptable to bearing failure because of being
submerged now and then, plus the small tires make MANY revolutions per mile. But,
the same principals apply to travel trailers.

It's much easier to spend a Saturday morning repacking your wheel bearings than
to call a tow truck when you're stranded along the Interstate. And how do you tow
a trailer with a bad wheel? Of course, if your A/S is a tandem axle, you can
remove the wheel/tire from the 'bad' spindle and continue, but you're now
throwing all that load onto a single wheel that had the same maintenance as the
failed one. Hmmmm...

Don't forget to use Wheel Bearing Grease, not plain ol' EP #2, and don't neglect
to change the seals. Repacking wheel bearings is not hard to do properly, but if
you've not done it before, have someone teach you the correct technique. Check
and ajust your brakes while you have the wheels off.....

<<Jim>>

JetBoy1011@aol.com wrote:

> I meantioned this over a year ago, but perhaps there's some new opinions. On
> a car, you repack the wheel bearing when you do the brakes, which could be
> 20-30,000 miles or several years. Why would the airstream need to be repacked
> so often??
> Dan