I decided to strip my Gearbox because I was not sure about the correct clearance between Mainshaft and bushes. ( see thread Jan 11, 2010 Examine Gearbox Mainshaft) And indeed the clearance was 0.016”. Much more than the running limit 0.006” (Ian Wright) So I ordered two new bushes for the Mainshaft Sleeve Gear. (4th gear) These (rolled) steel Bushes are at inside bronze plated and have a very heavy press fit. The old bushes have a chamfer. (machined after press) The new one’s not. Is this chamfer for an O-seal on both sides of the Sleeve Gear? This chamfers makes supporting surface smaller.
How can I clamp the Sleeve Gear in the Lathe for the best parallel and concentric machining the inside of the bushes after press fit?
Thanks in advance, Lammert de Vries

Hi Lammert...I don't recognise your description of the sleeve gear bushes...these are usually manufactured from solid bronze...where did you source them?
The chamfer on the outer end is made to accept a tapered felt seal that fits over the mainshaft.Personally I never fit one and it doesn't cause any problems. There is no seal inside the box, the end of the splines on the mainshaft run against the bush. Check that the ends of the splines are not worn or burred. Clean them up with an oilstone if necessary.
The inner bush should have the three lubrication holes drilled through it before fitting. As the oil holes are at an angle if you drill through with the bush fitted in the gear you are very likely to snap the drill as it breaks through.
If you have access to a lathe with a good three jaw chuck that runs true you can simply hold the gear on the splines and the surface that the bearing fits onto. That is how I do them. If the chuck is more worn you will have to hold the gear in a 4 jaw chuck and clock it up to run 'true' with a dial gauge....Ian

email (option): ian@wright52.plus.com

Ian, thanks for your very clear answer. The Bushes I ordered are steel outside and bronze inside. Made from steel sheet. Ends closed with a special connection. See British Only Austria’s Picture. I bought my Bushes from De Groot in the Netherlands. My old Bushes are the same type and manufacturer.
Regards, Lammert de Vries

Hi Lammert, very interesting..I haven't come across this type of bush in this application before. Does anyone else have information or experience relating to this? Were these bushes original fitment at some point?...and if so when?....Ian

email (option): ian@wright52.plus.com

Was just reading some of these old posts...That's a later "A" Series gearbox sleeve gear bush isn't it ? they had a steel backing.