New 3rd Motion Bearing (GBox)

[forbesg]

Hi Guys,
Presently rebuilding my 1098 gearbox. When I went to replace the 3rd motion bearing (22A465), I noticed it came with a shim. The original does not (obviously an adaptation since manufacture), it would seem logical that the shim fits between the bearing and 1st gear. Though I better double check, before going to far.

Regards

Grant.

[bmcecosse]

To be clear - is it the new /replacement bearing that has arrived with a shim ? Is the new bearing otherwise identical to the old one - or is it slightly thinner?

[forbesg]

Hi BMC,
Yes the new bearing has the shim. The cone appears to be difference between old & new.

[bmcecosse]

Cone ? Measure the width (thickness) of each bearing - are they identical?

[les]

The third motion bearing is not as original spec, by that I mean the inner race is not as wide, therefore shims are provided to overcome this. The bearing should have a circlip fitted when supplied. The inner bearing face opposite to the circlip should have a 0.040'' shim placed against it and the inner bearing face on the circlip side should have shims equal to 0.055'' this measurement is different because the circlip in the outer race is machined nearer to the edge than the original (the bearing goes in slightly further thus requiring thicker shimming to offset this. All this is the case for bearing number 22a465 from Moss Europe.

[bmcecosse]

Useful information there - do MOSS advise this when they supply the bearing ?

[les]

Yes , all credit to them, they supply a sheet of paper with the appropriate measurements and shims. They didn't explain the circlip difference, but I suppose that was not needed.I found a place that said the original bearing was available but rather expensive. The original was a ransome and marles.

[forbesg]

Thanks for that Lads, brilliant .
Wasn't aware of the changes to the the circlip groove.
FYI mine didn't come with a circlip (I used the original) nor documentation, I imported mine from an well known English minor parts supplier.
However now that I'm aware of such things, I will check it out. Once again thanks.

[les]

I'm wondering why you only got one shim with your bearing, I think mine came with 4.