AJS & Matchless Owners Club

Okay, I am ready to start the reassembly of my G9 engine. Is there a right or wrong way to insert the bearing into the case? I assume the printing on the outer race faces into the case but both sides look the same to me. I know I must heat the case and bang it on the bench to get the old one out. I’m a bit worried that won’t be easy. Any advice is greatly appreciated.

I’ve read through the forum threads and will try heating the cases in the oven. The peening is scraped off so might go okay
Just need to know which way to insert the bearing into the case or maybe it doesn’t matter. Thanks all.

I am not sure it matters. I put the writing facing out so i could see what the reference was on the bearing if i ever need to change it again!

I have successfully removed main bearings by placing the case in a washing-up bowl of boiling water and then only needing light taps to remove the bearing with a drift. Memsahib need never know !
Worth a try first, before stinking the house out.

1608 wrote: ↑Tue Mar 05, 2024 10:29 am I have successfully removed main bearings by placing the case in a washing-up bowl of boiling water and then only needing light taps to remove the bearing with a drift. Memsahib need never know !
Worth a try first, before stinking the house out.

Far more aromatic than some of my ex-wife's cooking efforts. Whenever she was doing a roast I had to take the battery out of the smoke detector.

I have found them very difficult to remove. I've had them in the oven stinking hot and banged them down on 4" thick wood. Didn't move and yes I did scrape out the peening first. An old mechanic told me to put a couple of rings of mig weld around the inside and they'd just drop out. I was very sceptical but I thought I'd try it. It worked perfectly and the bearing rings fell out. No damage and no problem. I've just repeated it on my G11. Worked a treat. The weld must shrink them.
Dave.

Lots of good information there. Thanks.

Main bearings are in and the cases fitted together. The crankshaft turns smoothly but not easily. It does not exactly spin, but turns stiffly. How do I measure whether it is free enough to proceed? If not, what then? I followed the finger tight first procedure for the web and am not sure what to do next.

Are you sure they are a matched pair?

The cases? Not really. They were part of a box of parts, that seemed to fit. Is there a way to tell?