19-12-2018, 02:27 PM
(19-12-2018, 02:08 PM)Reckless Rat Wrote: Probably the case with a 4 speed crash - they seem to be the strongest and most reliable. Not so with the later synchro boxes. I bought a second hand 4 speed synchro box thinking that it would be an upgrade but it was knackered. Apart from the layshaft bushes being made from unobtainium the teeth on the 3rd/4th selector cones had been ripped off, there was considerable wear in the intershaft bearing and the selector forks were also badly worn. It looked like it had been full of water at some stage and overall it would have made a decent boat anchor but nothing more.
I completely agree Reckless that synchro boxes are more delicate - that's one of the reasons I now have a 4-crash in mine (£7.50 well spent!) When it comes to an entire box I would never take a chance on running one without a strip down - not unless I knew it had come straight from a working car. In Simon's case there's a limit I think to how much evil may be lurking between his 2nd and 3rd cogs.
When I rebuilt my synchro box (long time ago now) I ground a thou or two off the layshaft to clean it up (they are quite deeply hardened) and had new bronze bushes turned up to suit. Nothing fancy and they weren't line bored either but it was still running fine a couple of decades later. The synchro parts seem the most difficult area to me as I don't know what you can do (at reasonable cost) other than juggle them from one box to another.