A few years ago i installed a ruckstell axle with neoprene inside and outside outer bearing seals. The instructions as i recall said to pack the outer bearings and to plug the grease cups as no further greasing is necessary.
I did not follow the instructions and have been greasing once in awhile ever since. I have experienced no issues since then, but thought i would ask the question..am i causing a problem that just hasnt shown up yet?
I am using stock hyatt bearings and original sleeves.
Thanks!!
Vince M
your bearings are problably sealed better, but more grease cant hurt, all it would do is push the old grease out the seal.
as an old timer once told me, "it'll spit out what it dont want"
If the old grease is pushed into the axle no harm is done - but if it's pushed out into the emegency brake drum and you have a lined brake there, then you risk the emergency brake lining.
The inner seal may be softer, but the outer seal is probably less flexible when the hyatts wear and the axle tends to flex off center by the weight of the car?
Thanks guys. That was my thought too. I have rockys and the cast iron emerg. brake is inactive anyway, but that makes sense that it could affect a lined shoe.
Vince
Too much grease can hurt. Grease will thin somewhat with heat and circulate through the bearing. If their is not enough space due to excess grease you get no movement and no lubrication.
This happened on my toy hauler. I packed the wheel bearings like they taught me in auto school and they run nice and cool. Before I had been giving the bearings three or four pumps every few months of use. The entire inside cavity of the wheel hubs were full of grease.
Just my .02 cents
Phil I have to respectively disagree. You may have had a bearing failure but the cause would not be too much grease in a bearing. You could have popped a seal or had a mechanical failure.
Too much grease causes more friction and more friction causes more heat which can breakdown the design characteristics of the grease which then losses some of its lubricating properties. The Viscosity Is lowered making it easier for the grease to push past the seals. Overgreasing will also hydraulic the seals out of there seats or just rupture their membrane. This can also happen as a result of a pressure build up by heat alone caused by too much grease. This is one of the reasons for sealed bearings being used on high speed shafts.
Front wheel hub bearings will show a delamination to the roller bearings because of too much grease caused by heat.
Below is from Timkens web site:
Overfilling
Overfilling a bearing with too much
grease can cause excess churning of
the grease during operation and high
temperatures, resulting in overheating
and excess grease purging* (leaking).
Overheating occurs because the heat
generated cannot dissipate correctly,
continually building until damage oc -
curs. As the operating temperature
of the bearing rises, the oxidation
(breakdown) rate of the grease sharply
increases – doubling every 18º F.
Fred
Thanks Fred, I stand corrected. Besides bearing buddies, I would like to know how to overfill a bearing. I know the seals can be compressed out with a bearing buddy. I didn't realize that it can be done by hand.