Gearbox grief

[Diablo]

Mate of mine phoned me up with the same problem a few weeks ago. His JBL stamped bearing didn't sit deep enough into the casing when compared to Italian ones I had at my workshop.
I can't remember the exact measurements but check against your old bearing to see if there is a difference.
You can shim between the layshaft and the bearing but you will probably have to make one yourself although when those jap rear hub bearings were being used(can't remember what they were called) I used MBs shims they had made to space cranks with jap rods before the alpha cranks.

[Daggs]

I'm pleased to report i've resolved the issue. There were essentially three things happening;

1) Because i was tapping the layshaft home i was very slightly pushing the hub bearing out. Only a mm or so, I didn't realise because i had put the retainer plate on. That was one factor.
This drove me to make up a layshaft puller. Which i should have done a long time ago.
2) The endplate was not sitting down properly. On about my tenth fitting of it with no gears in the box. I felt it 'pop' and go down a tad. So something had been holding it up (probably one of the dowels was catching slightly in the dowel hole) Add this to No1 and there's a couple of mm. Plus the 2.4 mm which i have shimmed up. Gives in excess of 4 mm.
Now i have a very nice .15mm float.
3) I had been struggling with this problem for several hours. I should have walked away from it earlier. A fresh start on a new day always seems to help. It certainly did today.

Thanks to all that offered advice.

[byron]

... A fresh start on a new day always seems to help. .

yep, often a good move if nothing is going right.
glad you got it sorted.