Bearing shim

Share your inventions, innovations & ideas - words are good but images are GREAT!
Post Reply
User avatar
Old Techo
Over 10 kay Club
Posts: 10440
Joined: Fri Dec 26, 2008 1:23 pm
Location: Melbourne

Bearing shim

Post by Old Techo » Thu Apr 09, 2015 12:05 pm

Recently I was faced with trying to replace the ball-bearings on my motor mower wheels. Clearly the bearings measured as an imperial size but I could only buy metric that was close enough to ID, OD and width. No imperial bearing size came near.

My metric bearing ID was right but the OD was a tad small. I was considering how I may tackle this slop but my first thought of using a thin strip of metal as a packer was out of the question because even the thinnest sheet metal I had was too thick. It suddenly occurred to me to try a feeler gauge.

There was not only a range of thicknesses but also nice and springy to place inside the wheel hub where the tension holds it in place. I have a few sets of feelers with some ancient ones passed their usefulness. By using the tip of a feeler I measured the slack between the bearing and the hub. It was about 16 thou. It may not sound much but on a 28 mm OD bearing it was quite sloppy. So an 8 thou feeler wrapped around 360 degrees was needed. Next I cut the feeler in half lengthways with tinsnips. The full width wasn't needed and also this gave me 2 packers out of one feeler.

To ensure the feeler would not 'walk' under load I used some silicone between it and the hub.

I don't recommend this technique for high-load bearings, such as van wheels, but it could get one out of trouble in an emergency.


The wheel...
feel1.jpg

An old feeler gauge...
feel2.jpg

Split feeler fitted...
feel3.jpg

A snug bearing...
feel4.jpg
You do not have the required permissions to view the files attached to this post.
Regards, Old Techo
2007 Prado Grande Diesel Auto
2004 Roadstar Limited Edition

User avatar
dieseltojo
Major contributor
Posts: 5713
Joined: Wed Jun 24, 2009 5:06 pm
Location: Doveton vic

Re: Bearing shim

Post by dieseltojo » Fri Apr 10, 2015 6:52 pm

Hi OT,

So how would a clean up and a bit of silicone go. Just letting it set.?
I now have to note that I cannot accept owners ship, truth, quality, or veracity, of articles I may quote off the internet.
1929 Pop Top
Paul & Trudy. Plumber & Plumberess

User avatar
Old Techo
Over 10 kay Club
Posts: 10440
Joined: Fri Dec 26, 2008 1:23 pm
Location: Melbourne

Re: Bearing shim

Post by Old Techo » Fri Apr 10, 2015 7:41 pm

DT, for a mower job that's probably all that's needed. I used the silicone merely for shim security and not intended as load bearing.

Instinct has me develop engineering solutions for sometimes mundane tasks. The downside of just gluing the bearing in place with silicone is a potential lack of concentricity plus the difficulty of removing the bearing for future replacement. My method ensures ready removal. I have no idea how good these Chinese metric bearings may be in the hostile environment of a mower working hard in a wet environment.

Definitely using silicone alone is a likely quick fix. Longevity may be another question.
Regards, Old Techo
2007 Prado Grande Diesel Auto
2004 Roadstar Limited Edition

User avatar
J.REEVES
Rising star
Posts: 3767
Joined: Mon Nov 05, 2007 1:09 pm
Location: Newcastle

Re: Bearing shim

Post by J.REEVES » Fri Apr 10, 2015 8:18 pm

Hi OT,
I’m not going to let you get away with this fix!

If there is no suitable bearing available then the mower is too old and it should be in a museum!

I understand your point that the feeler was past its usefulness but I would think you would have some shim brass or steel shim laying around as that is what I would have used and then finish off with some Loctite bearing mount assuming the bearing is mounted in a metal insert.

I may have even considered buying a bearing with a slightly larger OD and grind the outside diameter down but a feeler gauge how could you.

JR
:razz:

User avatar
Old Techo
Over 10 kay Club
Posts: 10440
Joined: Fri Dec 26, 2008 1:23 pm
Location: Melbourne

Re: Bearing shim

Post by Old Techo » Fri Apr 10, 2015 9:03 pm

G'day JR,

Not quite ready for the museum. The mower is an Electrolux, Flymo with a 4.5 HP B&S engine. I bought it on 06/10/1995 to supplement my aging Victa Mustang, being my first mower that I bought on 01/10/1975 and still have the receipt for if you wish to see it ;-) I keep all of my purchase details in a database for insurance purposes.

The Victa still works but I don't use it due its noise. The Flymo has never failed me except for the wobbly rear wheels. Even this was not a failure but whilst I was buying Ebay stuff I added some bearings. I went through the Oz BSC catalogue and despite its extremely comprehensive imperial listing nothing came close. The metric bearings I finally chose are in fact for roller blades.

Clearly the Flymo had some one-off odd size bearings made. The wheels are plastic. Possibly I could have put them in my lathe and machined them out to the next metric bearing OD size. That would be much easier than grinding a bearing.

As good an idea it is I don't have any regular use for stocks of shim brass thus never ever had any. What I did have was several sets of feelers of which some were quite rusty and date back to my first car that I bought in 1960. I did what I usually do and made use of what was at hand.

Would you like me to stand in the corner for the next 2 hours? :mrgreen:
Regards, Old Techo
2007 Prado Grande Diesel Auto
2004 Roadstar Limited Edition

User avatar
J.REEVES
Rising star
Posts: 3767
Joined: Mon Nov 05, 2007 1:09 pm
Location: Newcastle

Re: Bearing shim

Post by J.REEVES » Fri Apr 10, 2015 10:59 pm

OT,
As you have a lathe machining the wheel to take a standard bearing sounds like the best option to me.

So you have a receipt on the old Victor do you expect a full payout on the original value if something happens to it?

I knew a bloke that I believe deliberately burnt his house down to get the insurance payout but after the insurance company valued his separate undamaged garage and items in his garage he found his payout on the house was not as much as he expected.

Standing in the corner is out these days but if you have a naughty mat then five minutes on the naughty mat will do for destroying the feelers.

JR
:razz:

User avatar
dieseltojo
Major contributor
Posts: 5713
Joined: Wed Jun 24, 2009 5:06 pm
Location: Doveton vic

Re: Bearing shim

Post by dieseltojo » Sat Apr 11, 2015 7:14 am

Well now I didn't know the man had a lathe......You could have simply taken an old Alvey fishing reel and honed out a perfect centre diameter..... or a wheel off the golf cart.....or the new babies pram :)
I now have to note that I cannot accept owners ship, truth, quality, or veracity, of articles I may quote off the internet.
1929 Pop Top
Paul & Trudy. Plumber & Plumberess

User avatar
Old Techo
Over 10 kay Club
Posts: 10440
Joined: Fri Dec 26, 2008 1:23 pm
Location: Melbourne

Re: Bearing shim

Post by Old Techo » Sat Apr 11, 2015 7:56 am

dieseltojo wrote:Well now I didn't know the man had a lathe
Hmmmmmm.... DT.... first signs of dementia eh? :mrgreen:

You saw my lathe here.... http://candm.com.au/forum/viewtopic.php ... 77#p139277

and commented on same here.... http://candm.com.au/forum/viewtopic.php ... 95#p174395 ;-)
Regards, Old Techo
2007 Prado Grande Diesel Auto
2004 Roadstar Limited Edition

User avatar
Old Techo
Over 10 kay Club
Posts: 10440
Joined: Fri Dec 26, 2008 1:23 pm
Location: Melbourne

Re: Bearing shim

Post by Old Techo » Sat Apr 11, 2015 7:59 am

J.REEVES wrote:Standing in the corner is out these days but if you have a naughty mat.....
Are they the ones like Mally's that keep blowing away in the wind ? :rolleyes:
Regards, Old Techo
2007 Prado Grande Diesel Auto
2004 Roadstar Limited Edition

User avatar
dieseltojo
Major contributor
Posts: 5713
Joined: Wed Jun 24, 2009 5:06 pm
Location: Doveton vic

Re: Bearing shim

Post by dieseltojo » Sat Apr 11, 2015 8:41 am

He He He... :)
I now have to note that I cannot accept owners ship, truth, quality, or veracity, of articles I may quote off the internet.
1929 Pop Top
Paul & Trudy. Plumber & Plumberess

Post Reply

Return to “PICS - unsung inventions & ideas”