I read a lot about these but there are 3 bearings.
George C advises to replace the ball bearing left on the short axle(layshaft) by a roller and gives dimensions NJ203 roller.
But what about the other two.
When i measure and compare on different sites they are almost the same but english and metric bearings are not totally the same.
What are the correct bearings and sizes for the dollshead and where do i by these quality bearings.
The three bearings are available from R G M ,i have just rebuilt a 1948 Inter gear box using the roller brg and the two ball brgs
Can anyone give me the bearing reference numbers for my dollshead box ? ( ex - 1948 ES2 )
If the 'upright' and 'dollshead' are the same, then the Andover Norton site has exploded diagrams and the corresponding Norton part numbers you need. All the main and layshaft ball/roller bearings seem to be unchanged right up to the AMC boxes on the last Dominators.
For the "Upright 'Box", (Andover Norton)
Sleeve gear pic shows A2/316, (a 1654Z, 1 1/4"x2 1/2" x 5/8" deep groove ball,single sided shield bearing), expensive at £28.80+VAT. This size can be had much cheaper from a bearing factor.
Mainshaft other end is Norton 04.0099 (A2/321 or A11M/322), doesn't show the bearing number, but the size is 1 9/16" x 5/8" x 7/16". Not too dear at £9.85 +VAT
Layshaft one end is NJ203E as you say, 'other end' is a bush in the kickstart shaft (04.0032 or A2/354) that costs a reasonable £9.85+VAT. This bush seems to be the only bearing that was changed throughout all the different 'boxes, the Commando's introducing part '040146', but what the differences are I have no idea.
Hope that this helps,
Thanks George, this is very helpful: I also found I was able to order the crankshaft main bearings in C3 configuration from my local bearing supplier very much cheaper than elsewhere.