Wheel bearings/remove/replace/grease,etc.

[Jim Roth <ready4c@xxxxxxx>]

Hey y'all...time to stop lurking and get into this wheel bearing thing,
it seems to reappear in some form or another every six months or so, so
here are a few tips gleaned from previous posts....


GETTING THE HUB/BEARING CAP OFF:

>1. Can someone recommend a good tool for the removal of the front wheel 
>bearing grease caps. I tried a Snap-On slide hammer bearing puller but none 
>of the attachments would fit securely in the grease cap ridge. The cap in 

I've always used the HUGE size of channel-lock pliers.  Adjust the jaws
to the right size, CAREFULLY clamp down on the edges of the hub cab
(they're still called that, right?) with the tips of the jaws and gently
rock it out. On my plier, the last serration on the jaw just fits the
ridge on the hub cab nicely. Just to be clear, the plier should be
perpendicular to the plane of the brake disc. Works like a charm.  Just
be careful as you can really lever down on the cap and crush it.

PRYING OUT THE SEAL:

Um, pry out the seal. Don't reuse.


REMOVING THE RACES WHEN THERE ARE NO OR SMALL RELIEFS:

Use a large cold chisel instead of a punch. Perch each point of chisel
on the exposed race edge from the back. This gives two pressure points
on the race. Lean it over as far as you can in the hole (making sure
both ends of the chisel face are still on the race) and give it a whack
with a 1 to 2 lb hammer. Switch 180 degrees and do it again. It soon
rocks free. Keep your blows even or you will cock it and have a hard
time. Switch to a regular punch once the race is down in the hole
enough. Make sure you have on leather gloves and safety glasses for when
you slip or a piece of the chisel decides to fly.


PRESSING RACES BACK IN:

I generally follow the practices that have been recently posted, i.e.,
using the old race to press the new one in. This is what I do
differently:

I take each different size of race (s/b two in our case) and grind them
down slightly so the are a slip fit. If you have access to a REAL
grinder then this is the way to go, although I've made most of mine with
a humble bench grinder.  The races are H-A-R-D so it takes a while on
one of these. Very important to use good safety/shop practice while
doing this. Eye protection, leather gloves, a good tool to hold the race
while grinding, etc., or at the very least you will be pulling the race
out of your drywall after the grinder takes hold of it and flings it. 
Anyway, once this is done, use a hardwood block to lay on top of your
"pressing tool" to evenly distribute the blows of a 2.5 (or 1kg)
blacksmith hammer. If you take care when starting your new race (that
is, don't cock it), it should slide in evenly and easily.  

Here's the hardest part: store your new "tools" where you can actually
find them next time. 


PACKING GREASE INTO THE BEARING:

     >careful - i think you'd only want to pack bearing grease into your 
     >bearings if your hands are clean.  you don't want any grunge or
grit 
     >that might already be on your hands getting into your bearings.
     
   

Don't waste money on gadgets; cheaper & better since you have some
tactile sense on the state of your grease:

Wash your hands and find a clean spot on your bench. Use all clean
tools. This is important. Once you've cleaned the bearings spotless,
place blob of correct grease in a sandwich sized medium weight new
ziploc bag. Place bearing to be packed in the bag. Zip it closed.  Knead
and work the grease into the bearing. You can actually see it oozing out
of all the cracks next to the rollers. You get no junk into the bearing
this way, and you are assured of complete greasing since you can see and
feel it up close and personal. And your hands are still clean and won't
pick up any crud to add to your newly packed bearings.

Alternatively, you can use a un-ziplock sandwich bag.  Stick you hand in
a bag, with your hand thus protected, grab a blob of grease, grab the
bearing, invert the bag and knead. Don't forget to point the open end of
the bag away from you, lest you squeeze too hard.


PRESSING SEAL BACK IN:

Make sure you have the packed inside bearing sitting in the race first!
Or have a few extra new seals on hand for when you have to pry them back
out again. Use a bearing pressing tool (plastic, cheap) or make one from
jar top or other stiff, round item. Just make sure it only contacts the
metal part of the seal and does not touch the trubber lip. Use a block
of wood to distribute the taps evenly. You CAN do it without the use of
anything but a small hammer, but the odds are way against you.


TIGHTENING BEARINGS:

Follow the specs in the manual to the letter. Especially for ABS
equipped cars.  Tighten down (but not to the point of seizing up the
bearings) while turning wheel to make sure the races are seated. Then
back off and tighten to the correct torque (yes, torque) while turning
the wheel. Most of the torque settings are in lb/in (inches!), so you
might have to get a new 1/4" drive torque wrench. The old method of
tightening until tight, backing off one castellation on the nut, and
throwing a cotter pin in the hole is certain to make your bearings toast
sooner than later.

GREASE:

There are several greases specified out there. Use the one spec'ed for
your car. Any old "disc brake" bearing grease is not what it seems.
There are several different grades which are specified for a reason. I
have found this out the hard way, being rewarded with unwanted grinding
noises at the worst times and places.

- -- 
Jim Roth, White Rock (Los Alamos) NM USA
'94 Land Rover Discovery
'90 MBZ 300TE 4Matic
'88 ALFA Romeo Milano Verde (75/3.0QV)
'85 Maserati BiTurbo

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