AJS & Matchless Owners Club

Hi All,
FW Neill's book suggests reaming the timing side crankcase bush (16MS) prior to reassembly. OK. The Technical Data (p182) states 1.125" - 1.255". But what size reamer should be used? Should I measure the crankshaft and ream to fit with an adjustable reamer; use a 1.125" (1"1/8th)... or just give the job to a specialist? Your knowledge, as always, would be much appreciated.

Cheers,

Bob

BobbyG wrote:Hi All,
FW Neill's book suggests reaming the timing side crankcase bush (16MS) prior to reassembly. OK. The Technical Data (p182) states 1.125" - 1.255". But what size reamer should be used? Should I measure the crankshaft and ream to fit with an adjustable reamer; use a 1.125" (1"1/8th)... or just give the job to a specialist? Your knowledge, as always, would be much appreciated.

Cheers,

Bob

I gave mine (350 lightweight but similar set up) to a local engineer to do. I gave him the crank and both cases and he had to make jig some sleeves to line it all up to ensure all was in line before reaming the bush. Mine was fitted and then reamed. Also bear in mind the position of the large cut out in the bush for the oil pump gear presuming yours is the same as mine. Cost me £72 but he said most of that was the time setting it all up

Hi

That's one hell of a large range! - over an eighth of an inch!

Not having read the documentation to which you refer, but I would have thought the whole point of the exercise would be to line ream the bush to ensure concentricity with the drive side bearing and sliding fit on the timing side crank shaft axle.

Regards Mick

Edited to add: The workshop manual states 'ream in situ to 1.125" + 0.0005" - 0.0000" - Have you misread your literature?

Regards Mick

Think there was a special reamer made just the correct size for this job. Mine was done just as mentioned abvove

My mistake Mick. Should read 1.125" - 1.1255". Thank you for your advice gentlemen. Having spoken to other 'AMC aficionados' - suggestions range from 'if the crankshaft fits... go with it. When the war-time engines were repaired they didn't mess about.' - to line reaming as you suggest Mick. Neill just states "the bush must be reamed to size as insufficient clearance between bush and shaft will result in seizure." He goes on to say that "in production, this bush is 'fine bored' on a special machine designed for the purpose."
My feeling (hope) is that this will be the last time the crankcase will be split (by me at least!) so best have a proper job done rather than DIY.

You will need an inline reamer, long enough to locate the tapered slide in the other bearing, perhaps one of the Cheshire members will have one of the correct size, these are normally adjustable. If not go to a recommended engineer!

Reviving this thread. I have the timing side bush in. Still have to remedy the stake pin position and I'll be fitting a small loctited grub screw. In order to drop the bush in (literally, hot case frozen bush)I had to make a groove with enough clearance to clear the pin easily. The pin will not now really serve it's purpose and I'm not fiddling with it as it is so securely in place that I couldn't remove it.

Anyhow, with drive side bearing in place the bush needs reaming/boring.

I have had an unnecessary expensive unpleasant experience with the usual "go to" motor engineers on Teesside. Can anyone make a recommendation? Considering the money spent so far, I'd be prepared to travel out of the area, particularly Newcastle.

Johnny B

Otherwise it's Dudley's suggestion, but I'm likely to stuff the job.

Giving this a bump as no-one seems to have any recommendations so far.

Johnny B

Johnny I was wondering if a line boring company that works on something like excavator boom bushings in the North East might be able to quote you?


Iron Head

Thanks for the suggestion.

Johnny B