The Ford Barn

Tom Elliott · 01-26-2015, 09:04 PM

How much bigger on average is a shaft diameter than the bearing when pressing on a new bearing? I'm guessing 1 to 2 thousanth's. If the shaft diameter is the same size as the bearing I.D. can knurling work to increase the diameter? Thanks, Tom

Joe K · 01-26-2015, 09:47 PM

Probably on the smaller range, like 0.0005 to 0.001 for the size of bearings we deal with. 2 thousandths on 2 inch diameter is true interference fit. Bearings want to be a bit less than that.

Knurling is a common dodge for those whose inner races/roller turn.

Heh. 1978 Isuzu/Chevrolet LUV Truck. Started making a "scree-scree" noise about 4 months after the one year manufacturer's warranty ran out. I brought it over to my friend and Shop Superintendant Fred Baldelli at the Westboro, MA Chevy garage. He came back with the diagnosis that the front wheel spindles were shot (?) likely defective from the beginning, and that I was looking at 3 weeks minimum to get replacements from Japan.

I NEEDED that truck to get back and forth to work.

"Fred, are the spindles blue?"

"No."

"Could we knurl them and increase the interference between the spindle and the bearing inner race?"

"We could if we had a portable knurl. But the shop doesn't have a portable knurl."

"Oh yes you do" my reply.

I went over to Fred's toolbox, grabbed out a pair of stout vise-grips, adjusted the setting, and then with all the hand strength I could gather clamped them over the spindle, upsetting the metal and creating grooves/ersatz knurls.

The inner race now required a punch to get it on over the knurls, but once in place - it wasn't moving.

Fred did recommend I replace the spindles as soon as I could. I drove the truck for another two years after that before I traded it in on a better car. I guess that constitutes a "replacement?"

Sorry. A story from my mechanic formative years.

Joe K

Tom Wesenberg · 01-26-2015, 11:14 PM

What shaft and bearing are you asking about?

Tom Elliott · 01-27-2015, 10:33 AM

Actually the bearings on both sides of the carrier. Thanks, Tom

Joe K · 01-27-2015, 10:44 AM

Some use a pin-punch and upset the cone seats in the trumpets. Some use Green Loctite.

The carrier could be turned in a lathe and a knurling tool used on the race seats. Or a portable knurl used similarly. Or the pin-punch. Or green loctite. Or Vise grips.

Be careful not to crush the bearing seat with the last. Pin punch/loctite sounds preferable.

Portable knurl shown below. One with three wheels would be preferable.

Joe K

d.j. moordigian · 01-27-2015, 10:54 AM

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Quote:

Originally Posted by Tom Elliott

Actually the bearings on both sides of the carrier. Thanks, Tom

Use Tom Endy's tutorial, for the rear ends.....also, use a lathe too
knurl the race area....
.
http://www.ocmafc.org/techarticles/T...0Re-Edited.pdf
.
www.ocmafc.org Orange County Model A Ford Club (Tom Endy's Technical Articles) (California)

Tom Endy · 01-27-2015, 01:22 PM

There is a 2014 revision to the document on the web site of the Santa Anita A's of Arcadia, California. More information and larger photos.

Tom Endy

http://www.santaanitaas.org/technica...tech-articles/

Tom Elliott · 01-27-2015, 07:00 PM

I have been using Tom's tutorial and boy has it been helpful. Setting up the specs on the rear end couldn't be easier with this information. Thanks to all for the suggestions.

01-26-2015, 09:04 PM	#1
Tom Elliott Senior Member Join Date: Oct 2014 Location: Peyton, Co. Posts: 100	Shaft and bearing difference? How much bigger on average is a shaft diameter than the bearing when pressing on a new bearing? I'm guessing 1 to 2 thousanth's. If the shaft diameter is the same size as the bearing I.D. can knurling work to increase the diameter? Thanks, Tom

01-26-2015, 09:47 PM	#2
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Shaft and bearing difference? Probably on the smaller range, like 0.0005 to 0.001 for the size of bearings we deal with. 2 thousandths on 2 inch diameter is true interference fit. Bearings want to be a bit less than that. Knurling is a common dodge for those whose inner races/roller turn. Heh. 1978 Isuzu/Chevrolet LUV Truck. Started making a "scree-scree" noise about 4 months after the one year manufacturer's warranty ran out. I brought it over to my friend and Shop Superintendant Fred Baldelli at the Westboro, MA Chevy garage. He came back with the diagnosis that the front wheel spindles were shot (?) likely defective from the beginning, and that I was looking at 3 weeks minimum to get replacements from Japan. I NEEDED that truck to get back and forth to work. "Fred, are the spindles blue?" "No." "Could we knurl them and increase the interference between the spindle and the bearing inner race?" "We could if we had a portable knurl. But the shop doesn't have a portable knurl." "Oh yes you do" my reply. I went over to Fred's toolbox, grabbed out a pair of stout vise-grips, adjusted the setting, and then with all the hand strength I could gather clamped them over the spindle, upsetting the metal and creating grooves/ersatz knurls. The inner race now required a punch to get it on over the knurls, but once in place - it wasn't moving. Fred did recommend I replace the spindles as soon as I could. I drove the truck for another two years after that before I traded it in on a better car. I guess that constitutes a "replacement?" Sorry. A story from my mechanic formative years. Joe K __________________ Shudda kept the horse.

01-26-2015, 11:14 PM	#3
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Shaft and bearing difference? What shaft and bearing are you asking about?

01-27-2015, 10:33 AM	#4
Tom Elliott Senior Member Join Date: Oct 2014 Location: Peyton, Co. Posts: 100	Re: Shaft and bearing difference? Actually the bearings on both sides of the carrier. Thanks, Tom

01-27-2015, 10:44 AM	#5
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Shaft and bearing difference? Some use a pin-punch and upset the cone seats in the trumpets. Some use Green Loctite. The carrier could be turned in a lathe and a knurling tool used on the race seats. Or a portable knurl used similarly. Or the pin-punch. Or green loctite. Or Vise grips. Be careful not to crush the bearing seat with the last. Pin punch/loctite sounds preferable. Portable knurl shown below. One with three wheels would be preferable. Joe K __________________ Shudda kept the horse. Last edited by Joe K; 01-27-2015 at 10:50 AM.

01-27-2015, 01:22 PM	#7
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: Shaft and bearing difference? There is a 2014 revision to the document on the web site of the Santa Anita A's of Arcadia, California. More information and larger photos. Tom Endy http://www.santaanitaas.org/technica...tech-articles/

01-27-2015, 07:00 PM	#8
Tom Elliott Senior Member Join Date: Oct 2014 Location: Peyton, Co. Posts: 100	Re: Shaft and bearing difference? I have been using Tom's tutorial and boy has it been helpful. Setting up the specs on the rear end couldn't be easier with this information. Thanks to all for the suggestions.