1931 rear spring & perch bushing
 

when replacing the shackle it says to replace the two bushings also. Macs says to drill out the old one with a 14.5mm bit but it looks to me like it would make the Perch very thin on mine anyway. The new bushings look pretty thick. My shackles were very worn out. Any input would be appreciated.
Thanks

Re: 1931 rear spring & perch bushing
 

Many perches have been neglected over the years to the point where they are very badly worn on the under side. The bush doesn't contribute to the strength of the setup so if your perches are that bad that the shackles have left a hollow spot on the top of the axle housing (trumpet), you might be best advised to repair them. It isn't difficult. Find yourself a piece of copper or brass rod the size of the hole in a good perch. Insert it into your worn one and arrange for it to be held in the "up" position - the opposite direction to the worst wear. Now proceed to replace the metal that has been worn away with weld. The weld will not adhere to the non-ferrous rod. Once done, remove the rod and insert your new bushes.
I'm sure others will chime in here too.

Re: 1931 rear spring & perch bushing
 

Sometimes its difficult/nay impossible to remove a copper or brass rod.
I’ve used gouging rod which is carbon; it can be broken out with punch, chisel, etc
It’s available from McMaster Carr
Can’t remember if it’s 3/4 or 7/8”

Re: 1931 rear spring & perch bushing
 

Bratton's sell a 14.5mm drill bit for the purpose of using it as a reamer once a new bushing has been installed, if need be. I bought one to use for checking the fit, however Bratton's bushings do not need to be reamed, they are always a good fit. I don't see how a 14.5mm drill bit would drill out the old bushing.

The old shackle bushings can usually be driven out with a tool made from an old pedal or clutch release shaft turned down to fit inside the bushing with the outside edge the same size as the outside diameter of the bushing. A hammer will usually drive them out, for the stubborn ones I occasionally have had to use the shop press.

Bratton's sell such as tool, part number 5881 $8.90 described as a spring and perch bushing driver.

Tom Endy

Re: 1931 rear spring & perch bushing
 

All true !! I would add that the brake backing plates must be removed to achieve direct acess to the bushing bores when hammering out the old bushings. Takes a few good wallops to get the bushings moving but they will come out. My new bushings did not need to be reamed but the bushings in the new spring needed reaming before the shackle shafts would fit.

Re: 1931 rear spring & perch bushing
 

Tom, why would you need to ream the NEW bushing if it’s installed already? The new shackles fit the new bushings just fine.
Thanks