Date:         Fri, 20 Apr 2012 09:45:42 -0700
Reply-To:     Alistair Bell <albell@SHAW.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@SHAW.CA>
Subject:      Re: rear wheel bearing question
Comments: To: Don Hanson <dhanson928@gmail.com>
In-Reply-To:  <CAHTkEuKs=00hPhn-D9F+5a6ZZNoO9rmqkEVnL3PPX0c_6KGxYw@mail.gmail.com>
Content-Type: text/plain; charset=us-ascii

Sorry Don, but to me that doesn't make sense - how can you pack the housing so full of grease that the balls in the races cannot push out excess grease? After a few turns of the bearing, the balls will have cleared a path in the race, leaving only that thin layer of grease on the metal that actually does the job. I don't see how 5 oz of grease 2 inches away in the housing is going to help things.

And if you could pack the housing 100% full, wouldn't thermal expansion force grease out of the end seals?

I understand the types of grease used, I used a good quality synthetic wheel bearing grease. And in other applications (some much more demanding than the vanagon wheel bearing)  I have used sealed bearings.

Come to think about it, aren't the bearings in the alternator sealed? Shielded at least. 

alistair


On 2012-04-20, at 9:07 AM, Don Hanson wrote:

> 
> 
> On Fri, Apr 20, 2012 at 8:46 AM, Alistair Bell <albell@shaw.ca> wrote:
> After I replaced a relatively new inside rear wheel bearing the other day, I got to thinking about how the grease is supposed to stay in that bearing. It is an open ball bearing (17 mm id, 35 mm od, 17 mm thick ,NSK6207 C3 or KOYO 6207R) and when you are installing your supposed to pack the bearing itself with grease and also add grease in the housing (where the spacer is). I don't understand how adding grease to the housing helps, I can't see how grease there is supposed to get into the bearing.
> 
> So I wonder if using a sealed version of the bearing would be better? They are available, KOYO 6207 2RS for example.
> 
> Am I missing something in my understanding of ball bearings in this application?
> 
> alistair
>    I think you are meant to put enough grease into the hub so that there is no room for the inner bearing to shed the stuff into the space between the bearings.   That is what I did.   Also, there are two types of grease, one is marked "High Temp" or "Disc Brake"...I used that rather than just normal all purpose grease that could get spun out of the wheel bearings when it gets really hot.
> 
>   Don Hanson