Gearbox rebuild

Have got a noisy bearing on my Sp20 SC (synchro) box (started clacking under load) resulting in no further use in case damage is done..  Box is out and split but I haven't separated the main shaft/synchro assy or removed the layshaft yet.  The offending bearing appears to be on the layshaft.  Before I do the final round of disassembly any pointers/warnings/things to watch? - One of the Mainshaft bearings is also a little baggy so it makes sense to completely re-bearing the box whilst its out and apart.  All words of wisdom appreciated  I see that the parts list mentions a  Special ball race No 1300 on each shaft - are these available and if so where?  Shaun  PS - apart from the  bearings the box appears to be in superb condition , reflects how well it behaves on the road.. Posted by shaun matthews 15/04/2013 11:58:16

Box is apart, all shafts split except primary.  As several bearings are worn I intend to change them all - Believe  I have located replacements for all except the 3/4 x 1 1/8 x 1 3/4 spiral roller cage between Primary and main shafts. 2 questions:-   Anybody know a source of the spiral roller assy?  I assume the primary shaft is simply pressed up around the large roller bearing or am I missing something clever and Alvislike? Posted by shaun matthews 23/04/2013 21:38:18

Shaun, I recently bought a bearing for inside the end of the crankshaft on my 1936 Silver Eagle, it is a similar bearing to the one you need, but smaller. I asked the vendor if he had one, and this was his reply...  "James E. Ducharme" <info@vintageautoparts.us> wrote:  Ian:  Good to hear from you again!  Yes, I have a huge selection of roller bearings.  By application, I have the Clutch Shaft Front Roller Bearing for the 1935 Alvis Firebird and the Reverse Idler Roller Bearing for the 1928-29 FWD Alvis.  I also have some Timken tapered roller bearings for 1945-60 Alvis models (i.e. front wheel, rear wheel, differential, pinion and steering pivot).  I did some checking for a bearing with the dimensions you forwarded (3/4 x 1-1/8 x 1-3/4).  I don't seem to find a bearing with those exact dimensions was ever manufactured.  Is it possible either the ID or length are off by an 1/8" or 1/4"?  I'll look some more in a couple of my old roller bearing catalogs and see if I can come up with something.  Are you able to provide an "end ring" number?  Could you have the Alvis member email me so I can confirm each dimension and shaft OD as well as the application.  Thanks, Jim  ..... He may be able to help you if you can find any numbers on it etc... Give him a try!  Ian Posted by IanHardaker 24/04/2013 21:39:23

Ian  Thanks for the tip.   Surprisingly (and this is a complement  to a company that I have, at times, had a 'stressful' relationship with) Red Triangle have the drawings but no stock so are having one manufactured for me at the very reasonable sum of £42 +tax  and with only a few days lead time. My faith in them is restored.  Shaun Posted by shaun matthews 26/04/2013 15:40:47