Whitworth wrenchs

I just got in a super blend lay shaft bearing and a gasket set and am preparing to tackle a gearbox rebuild. I understand the gearbox is Whitworth standard and I'm wondering which size wrenches to buy. I might as well get a set that will allow me to do general engine work also. I looked at the tech hints on Old Brits website for the gear box rebuild. He uses an old chain to lock the main shaft to remove the nut. I don't have an old chain. Is there another method. He also shows how to check the end play. Is this necessary with the super blend?

I just chucked the shaft into my vise to remove the nut. Worked fine. Shaft is hardened steel, won't get hurt unless you really go silly buggers on it.

htown16 said:

I just got in a super blend lay shaft bearing and a gasket set and am preparing to tackle a gearbox rebuild. I understand the gearbox is Whitworth standard and I'm wondering which size wrenches to buy. I might as well get a set that will allow me to do general engine work also. I looked at the tech hints on Old Brits website for the gear box rebuild. He uses an old chain to lock the main shaft to remove the nut. I don't have an old chain. Is there another method. He also shows how to check the end play. Is this necessary with the super blend?

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I'm thinking to remove the trans outer cover while the trans is still in the bike.
Remove the nut while in gear with the rear brake on to keep shaft from turning.
I've never done it but it sounds reasonable.

Bob

htown16 said:

Is there another method. He also shows how to check the end play. Is this necessary with the super blend?

Click to expand...

Both the previous suggestions would work fine - I would generally do as much stripping as possible with the gearbox in the bike, but as mine was a complete rebuild, it was done one the bench with the splined shaft clamped between two pieces of wood in a vice.

The end play issue is specific to the superblend layshaft bearing, so the answer is definitely yes :mrgreen:
The original bearing positively located the layshaft with no endfloat, whereas the superblend doesn't. I followed the OldBritts advice and it took about ten minutes to get the clearance right using Isolastic shims.

Thanks for the replies. The gear box is out of the bike. Sounds like clamping it in the vise with blocks of wood will work. I'm ready to order the wrenches but not sure what sizes to get. Figured a set of sockets and combination wrenches.

i think british only is running a sale on whitworth tools. pretty good deals

htown16 said:

Thanks for the replies. The gear box is out of the bike. Sounds like clamping it in the vise with blocks of wood will work. I'm ready to order the wrenches but not sure what sizes to get. Figured a set of sockets and combination wrenches.

Click to expand...

I've got my gearbox apart on my '72 to replace worn gear bushes. The seven nuts holding the inner cover on are 1/4 W. The nut holding the mainshaft on the bearing in the inner cover is 1/2 W. That's about it unless you need to take the shift ratchet assembly apart. I've got a set of open end whitworth wrenches I bought from Raber's in San Jose...Dowidat brand made in Germany. Also have five whitworth sockets...Snap-on brand.

While you're into your's suggest you have the outer cover machined and insert oil seals for the kickstart and gearshift shafts.

I'm ready to order the wrenches but not sure what sizes to get. Figured a set of sockets and combination wrenches.

Click to expand...

The 7 piece Acesa brand (Spanish) combination wrenches are a good start. Well made and run from 1/2W to 1/8W. I also like the Koken (Japan) 3/8 drive socket sets. These sockets are thin wall and will reach the headbolts. These are both available from many BritBike vendors such as OldBritts, and British Cycle Supply.

You will still need to grind down box end wrench to get to the nut between the carburetors. I have a specially made (Heyco) obstruction wrench for this, but I haven't seen them for years.

I'm with Ron on this one. The Acesa wrenches are thinner and of better finish than the Indian choices. Regarding sockets, the Japanese Koken are available on ebay from time to time from the usual Norton and Triumph sources. If you're only buying one set, get the deep sockets; you can reach all of the headbolts without an extension. Stick with 3/8" drive, as you'll get thinner walls and an ease of use that is perfect for motorcycle work. Keep your 1/2" drive for big automotives.