Fitting new drive bearings AJS 18s

[rhunter]

I am fitting new drive bearings on to a new drive axle and they are very tight fit on axle.....to push them on to axle do you need heat for expansion.
Is it best to fit bearings, spacer and washer in to crankcase first, then heat up whole crankcase half and push on to axle??...any tips would be welcome......what is best procedure.......thanks....Robert

[paul knapp]

Hello Robert, some one who actually knows will ? come along and give you the correct tip, but I must say, heating an over tight (as you say) bearing isn't the way to go. Put a micrometer on the shaft and check if it has been made a bit on the full side I.E., too big on the diameter. All the bearings I have fitted are a neet, firm sliding fit.

Paul

[rhunter]

Bingo!!.....job done.......a quick skim of fine emery cloth on the shaft and inside bearing plus some WD and it slipped on pefectly....you live and learn!
,..........Robert

[rhunter]

1952 AJS Mod 18s ............I have finally assembled the crankcase and flywheels - problem is the flywheels are slightly stiff when being rotated - they will turn easily but not freely.
The first time I assembled it they were really stiff, wouldn't rotate at all - took all apart and with a little heat pushed home the drive bearings in the crankcase a little ....this seemed to help as they will rotate now but still the slightest bit stiff.......should I leave be and hope they will loosen up more when engine is up and running?.............Robert

[paul knapp]

Doesn't sound good to me, do you have any end float on the crank shaft? Your work shop manual will tell you how much you should have.

[dave16mct]

Hi Robert, check that the spacer washer between the bearings is not touching the outer race. It happened to me when assembling a single. I had to take them out and skim the outside of the washer down a bit. It them turned easily. Could also be your crank need re-alining? Did you put a new timimg side bush in? Dave.