The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 4x4 steering knuckles question

I took a LONG look at this, here is what I found out, from my post to the 60--66 gmc site.

K-model guys,

On the Steering Knuckle issue, I took the advice I heard here about not
mixing greases. I work with a guy who used to be in the BIG food
manufacturing (Pilsbury). He agreed about not mixing greases, oil, etc. He
says this is more important with modern lubes than it used to be due to the
advancements in lube technology. This guy is a genius, and a nice man.
Anyway, helped me navigate the lube jungle. Originally the factory filled
the wheel bearings and knuckles with a semi-solid/semi fluid grease. I have
seen this original stuff. The problem happens when the inside diff seals
begin to leak gear oil into the axle tubes.

The MOTORS manual says to mix 90wt and grease to get a semi-fluid
consistency goo to refill after service. The technicians at the oil
companies said not to do this. I had aluminum thickened (not aluminum
complex) non EP grease in the front bearings. The only compatible semi
liquid greases I could find came in 150$ 30lb pails, Mystik centralube was
my first option, but in 30lb pails. The tech kept saying it wasn't for disc
brakes. I finally held him down to admitting is was rated for wheel
bearings. It has a lithium hydroxy thickener and would work with lithium
General Purpose grease.

The aluminum semi fluid greases were all expensive (royal purple had one) so
I ended up washing out that grease aluminum wheel bearing grease and using a
plain lithium thickened (not lithium complex) #2 grease in the wheel
bearings and a lithium thickened 00 grease (about 1500wt) from Smitty's
Super S lubes. This lube is for cotton pickers and is sold in quarts (5$).
It has been in the knuckles for a month or two and no seepage at all. I
expect this stuff to thicken up when it gets cold but still sling. The
original DANA/Spicer sticker on these old trucks said to lock the hubs in
once a month? to lube things. They mean that the axle u-joints run
semi-submerged in semi fluid grease, when the axle shafts spin they throw
grease up onto the top Timken roller bearings that the knuckles pivot on. I
used a small amount of the #2 lithium grease for the locking hubs also.
Some had said that if you use wheel bearing grease, the hubs will not be
lockable in cold weather, which is true.

The lube techs said that although lithium is water resistant, it is far from
water proof. One said to mix a couple of drops of water and lithium grease
on you palm and see the milkiness of the mix. Try that with an aluminum
base. In short, wipe some lithium grease on a window and some aluminum
grease also, then try to wipe both off with a wet towel. I tried, it's dang
hard to get aluminum grease off. I had been told my whole life that lithium
was the grease of choice for boat wheel bearings, aluminum is better. I
have seen people pump whatever grease on hand into whatever needed greasing
also. If you do a google search for "grease compatability chart" you can
find out which greases are compatible. All lithiums are not, just as all
aluminums, sodiums and calcium thickened greases are not. The MYSTIK techs
were VERY helpful. Now I realize that a number 2 General Purpose lithium
grease is not ideal for wheel bearings, BUT, it is rated for wheel bearings
and is compatible with the Smitty's cotton picker grease. Timken recommends
NOT to use chassis grease because their extreme pressure EP additives like
moly are detrimental to wheel bearings, especially in high concentrations
like in EP chassis grease. I also found that the term "long and short fiber"
wheel bearing grease, and other terms like this are the old way of
specifying roughly, the length of the hydrocarbon chains in the grease. I
was brought up thinking that the there were actual fibers in the grease? All
this comes from about 2 months of research because I did not want to ruin
good wheel bearings early, OR have crud run out all over the place.

This is what I learned so far and what I put in my truck. We'll see what
happens on the bearings. If anyone knows or can correct anything I have
here, please email me at fireballv8@.... There was not much info on
the net about this subject at all and the only place to get the knuckle goo
pre made was novak adapters at 60$ a gallon, and they didn't know what kind
of thickener it used...back to mixing greases. I looked long and hard for
some science based answers that could be defended and none were out there,
not even guesses or recommendations. This might be a good addition to the
website when I get it condensed. Anyone looking for old 4x4 into will come
across info on the venerable Big Block V6. Maybe someone will pull a v8 and
find a BBV6 and GMC hood on their "other" GM truck while they are fixing up
their 4x4.

Hope this helps someone sleep better after fixing their k model.

Mike Green

Durant, OK