05-09-2023, 04:44 PM
I think you are right about the 'OOO' mark Dennis, though I couldn't tell you what it means in detail, nor whether it's likely to be a problem on an A7.
I assume 'narrow bearings' is a reference to the later narrow width A/C pair - as opposed to the earlier ball & roller set-up. Naturally the new lip must be located to suit one or the other. If you have a copy of the Companion you can extract the relevant dimensions out of Jack French's article on p.112 & check what depth you have on the case itself.
No marks on the races is good news. Older bearings often have corrosion etching (dark marks which won't polish off) and these do affect bearing life - by how much is another question. You certainly don't want anything you could feel with a finger tip.
Paraffin is fine for cleaning but it does tend to promote corrosion over time - I'd be inclined to blast it out with WD40 over a basin.
I assume 'narrow bearings' is a reference to the later narrow width A/C pair - as opposed to the earlier ball & roller set-up. Naturally the new lip must be located to suit one or the other. If you have a copy of the Companion you can extract the relevant dimensions out of Jack French's article on p.112 & check what depth you have on the case itself.
No marks on the races is good news. Older bearings often have corrosion etching (dark marks which won't polish off) and these do affect bearing life - by how much is another question. You certainly don't want anything you could feel with a finger tip.
Paraffin is fine for cleaning but it does tend to promote corrosion over time - I'd be inclined to blast it out with WD40 over a basin.