Knurling: A question for you machinist types

[BURN-BROS]

There apparently is no such thing as oversize races to fix the problem. Oversizes ball bearings, yes. I don't know if its fact but my bearing vendor does it for a living.
For what it will cost to repair the problem, It should exceed the replacement cost of a case from a wrecking yard.


Aaron

[Geary]

Hayden at Windrush does the best CORRECTLY CENTERED bearing bore repairs of these housings, with the proper interference fit, so I would highly suggest that you contact him. Sleeve to housing fit is .005+" interference fit, and sleeve to bearing is about .0015" interference. But how do you intend to center correctly for two boring operations without the proper jig?

[sammyg2]

I have lots O' parts overlayed with hard chrome or flash chrome every week for my shop and while most are either steel or stainless steel, occasionally we have it done on aluminium. I'll ask my chromer/grinder next time I see him if they do anything special because of the aluminium. For all I know it could be a completely different process.
The only concern I'm aware of is thermal growth where the aluminium grows more than the chrome but that only becomes a problem in large diameters or at relatively higher temperatures.

[Steve@Rennsport]

Originally posted by Wil Ferch
I'm ( somewhat ) familiar with hard chrome.
How do you do that to an aluminum case? I thought this only works on ferrous metal parts.
---Wil

Hi Wil:

You can indeed chrome plate an aluminum part,....

Long before the word "Nikasil" came into being, Chromal cylidners were the rage and all 4-cam Carrera's used these things. These are alloy cylinders with a textured (for oil retention) hard chrome surface. Theye were notorious for oil consumption as rings had a hard time with the surface, but it was fine in certain applications.

We also used Chromal-type cylinders for many years in 2-stroke racing motorcycles.

[klaucke]

My father is an engineer at one of the biggest knurling companies, he said this is a common solution to holes, to knurl and then bore out 50% of the (now raised) knurl for the bearing to grip. I don't think it's a good idea on a tranny in this situation though.