How much grease do you put in your hubs?

How much grease do you put in your hubs?

  • I just pack the bearings.

    Votes: 11 12.9%

  • I pack the bearings, and fill about half the empty space up.

    Votes: 19 22.4%

  • I pack the bearings and fill the empty space.

    Votes: 27 31.8%

  • I pack em, fill the space, and fill the cap, and pump more in every so often.

    Votes: 28 32.9%
  • Total voters
    85
scooper77515

scooper77515

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When you do a hub overhaul on your trailer, how much grease do you typically use? This is for use with dust caps, not bearing buddies. If you use a different amount with bearing buddies and wish to share, post in thread, please.
 
R

ricohman

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Re: How much grease do you put in your hubs?

Pack the bearings and put a glob inside the hub. Filling the space is a waste of grease.
You will find that when you repack the bearings the grease inside the hub is mostly unused.
 
dingbat

dingbat

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Re: How much grease do you put in your hubs?

For best results, ample space is essential in the housing to allow room for excess grease to be thrown from the bearing and for heat dissipation. It is equally important to retain the grease around the bearing. Normally, the housing should be 1/3 to no more than 1/2 full of grease during bearing assembly.
Click to expand...

http://www.timken.com/en-us/solutio...apered_Roller_Bearing_with_Grease_English.pdf

I use maybe 3/4 of a tube of grease to repack all four wheels
 
bigdee

bigdee

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Re: How much grease do you put in your hubs?

Too much grease on tapered bearings is a BAD thing. I pack the bearings by hand and fill the cavity and dustcap about 1/4 full.....NO MORE!!!!
I have seen over-greased bearings lock-up.
 
scooper77515

scooper77515

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Re: How much grease do you put in your hubs?

Thanks for your responses AND your poll choices.

I asked this because I have had several caps and bearing buddies pop off recently, and doing searches on the web, recommendations from "experts" range from just packing the bearings all the way to the other extreme of filling all the voids and caps.

I wanted to see what procedure "real world" guys use and their success/failure rates.
 
BaileysBoat

BaileysBoat

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Re: How much grease do you put in your hubs?

bigdee said:
Too much grease on tapered bearings is a BAD thing. I pack the bearings by hand and fill the cavity and dustcap about 1/4 full.....NO MORE!!!!
I have seen over-greased bearings lock-up.
Click to expand...

Huh?
 
C

cliffblue

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Oct 26, 2010
Messages
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Re: How much grease do you put in your hubs?

On boat trailers only, I fill the hub completely with both buddy bearing caps or the caps with a rubber insert that you can remove to access the zerk fitting that greases the hub back to front. Just wipe off the water contaminated grease that you push out and replace the rubber insert. I believe the absence of air in the hub reduces or eliminates the vacuum caused by backing a hot trailer hub into cool water that can suck water past the seals or caps into the hub. On my utility trailer, I just pack the bearings and go, but I can't imagine any way too much grease could harm a wheel bearing.
 
SuperNova

SuperNova

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Re: How much grease do you put in your hubs?

chcliffb said:
On boat trailers only, I fill the hub completely with both buddy bearing caps or the caps with a rubber insert that you can remove to access the zerk fitting that greases the hub back to front. Just wipe off the water contaminated grease that you push out and replace the rubber insert. I believe the absence of air in the hub reduces or eliminates the vacuum caused by backing a hot trailer hub into cool water that can suck water past the seals or caps into the hub. On my utility trailer, I just pack the bearings and go, but I can't imagine any way too much grease could harm a wheel bearing.
Click to expand...
Absol-freakin'-lutely. I agree 100%. And for the exact same reasons.
 
MH Hawker

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Re: How much grease do you put in your hubs?

I have seen over-greased bearings lock-up.
Click to expand...


In 40 plus years of doing mining and industral maintance I have never heard of any such thing.


I have dexter hubs so it is pump them till the clean grease runs out the front.
 
oldjeep

oldjeep

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Re: How much grease do you put in your hubs?

I pack the bearings, fill the cavity with grease, fill the cover with grease, pump a few shots into the spindle until it oozes a bit and then put the rubber cover on. I never add grease between repacks. Generally call it good for 2 years and then repeat process. In my book any void could get water in it and then you get a big mess.
 
Scott Danforth

Scott Danforth

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Re: How much grease do you put in your hubs?

have bearing buddies on every boat trailer, and pump them full.

on a utility trailer, pack it full, and install the dust cap.
 
bigdee

bigdee

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Re: How much grease do you put in your hubs?

MH Hawker said:
In 40 plus years of doing mining and industral maintance I have never heard of any such thing.
Click to expand...

Overfilling may cause a rapid rise in temperature, particularly at high speeds because the rolling elements have to push the grease out of the way. This leads to churning in the grease, which produces heat. Adding more grease only worsens the problem.
I appreciate your expertise in 40 years of industrial maintenance. That has also been my career for the first 30 years and industrial engineering for the last 15.
 
bruceb58

bruceb58

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Re: How much grease do you put in your hubs?

Since Bearing Buddy advises to pack the hub completely full, where are all these trailers lined up along the road with locked up bearings from over greasing?

Curious at what speed this is supposedly happening at. The reality is that trailer wheel bearings rotate at a fairly low speed compared to many bearing applications.
 
dingbat

dingbat

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Re: How much grease do you put in your hubs?

bruceb58 said:
Since Bearing Buddy advises to pack the hub completely full, where are all these trailers lined up along the road with locked up bearings from over greasing?

Curious at what speed this is supposedly happening at. The reality is that trailer wheel bearings rotate at a fairly low speed compared to many bearing applications.
Click to expand...
It is a known fact that over greasing a bearing causes elevated temperatures in the bearing housing. In extreme cases enough to cause a catastrophic failure of the bearing system. Been there done that. A bearing failure on a 25K HP drive isn't pretty.

Stuffing a bearing housing full of grease in a "sealed" housing does nothing but put additional pressure on the rear seal via thermal expansion ultimately causing a failure of the rear seal.

Rear seal failures and contamination of the bearing lubricate as the result of that failure probably account for 95% of bearing failures on boat trailers. The real question is how many rear seal failures, and the subsequent bearing failures, can be attributed to over lubrication of the bearing housing?
 
bruceb58

bruceb58

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Re: How much grease do you put in your hubs?

dingbat said:
It is a known fact that over greasing a bearing causes elevated temperatures in the bearing housing. In extreme cases enough to cause a catastrophic failure of the bearing system. Been there done that. A bearing failure on a 25K HP drive isn't pretty.
Click to expand...
I can imagine there would be an increase in temperature but with a bearing that is rotating at only 780 RPM for a 15" tire at 60 MPH it can't be that bad. The heat from the braking alone will contribute WAY more heat into the hub that any over greasing would contribute. I am talking trailer hubs here...not some industrial machine running at extremely high RPM.

The bearing buddy has a spring that holds the grease at 3 PSI. With over 30 years of having bearing buddies, filling hubs until full, driving in 115? temps have never blown a rear seal or have ever had a bearing failure. This includes trips from Los Angeles to Canada(Over 2000 miles round trip) to Tahoe(1000 miles round trip) yearly.

If you blow out a rear seal because you pump them with a shot of grease every trip, than that is another story but its not because you initially filled them too full. If you follow the directions then there isn't a problem.
 
dingbat

dingbat

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Re: How much grease do you put in your hubs?

bruceb58 said:
I can imagine there would be an increase in temperature but with a bearing that is rotating at only 780 RPM for a 15" tire at 60 MPH it can't be that bad.
Click to expand...

I agree, but according to Bearing Buddy there is a high enough delta T in the bearing housing to generate a pressure differential that sucks water past a seal rated to 6-8 psi. That would take a considerable delta T to generate. You have other problems that need to be addressed at that point.

The way I look at, if you have a good seal there is nothing to worry about. A properly lubricated bearing runs cooler and there is less chance of blowing a rear seal due to expansion.
 
bigdee

bigdee

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Re: How much grease do you put in your hubs?

bruceb58 said:
I can imagine there would be an increase in temperature but with a bearing that is rotating at only 780 RPM for a 15" tire at 60 MPH it can't be that bad. The heat from the braking alone will contribute WAY more heat into the hub that any over greasing would contribute. I am talking trailer hubs here...not some industrial machine running at extremely high RPM.

The bearing buddy has a spring that holds the grease at 3 PSI. With over 30 years of having bearing buddies, filling hubs until full, driving in 115? temps have never blown a rear seal or have ever had a bearing failure. This includes trips from Los Angeles to Canada(Over 2000 miles round trip) to Tahoe(1000 miles round trip) yearly.

If you blow out a rear seal because you pump them with a shot of grease every trip, than that is another story but its not because you initially filled them too full. If you follow the directions then there isn't a problem.
Click to expand...

BBs are not normally overgreased.....they have a spring and a relief that takes care of thermal expansion. Another consideration that factors into this is preload. If there is not sufficient play between the bearing and castle nut a tapered bearing can quickly become a taper-locked bearing.
Grease and temperature can develop tremendous hydrostatic forces.
 
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