Hello,

I've covered this in one of my lengthy threads on total car rebuild. But trying to find that bit of information in a very lengthy thread can be tedious and I thought it would be prudent to just post this separately as a solution to the idler and tension pulleys on 1965 and 1966 Ford full size with FE big block engine. To my knowledge presently there is no other solution to rebuild the original pulleys. I wanted to share a technique I found to rebuild them. It does require machining, so anyone with a lathe can do this or you can print this out and take it to a machine shop and have yours done.

These pictures are from another Ford galaxie owner who asked me if I would rebuild his. So these are his pulleys and the process.

First step is purchasing these pulleys for another application. The diameter and pitch are correct, plus they have a bearing that is replaceable from here on out.

Here's his pulleys he sent me. He already ordered the replacement pulleys and sent those as well.

Next is press out the old pulley/bearing assemblies from the cast iron bases.

I like to work with clean parts, as his paint was flaking off the bases his bases were sand blasted.

This is 4140 Chromoly shaft rod that is 3/4 hard (tempered). This will be cut and machined into the new pulley supports.

It looks like the rod sections are annealed first, then sheared to length then tempered. To get a clean straight section and the best chance at a uniform temper I sliced a section off the end first.

Now centre drill.

Drill and tap for 3/8-16. I start with a brand new 1/4" drill bit. Mind you at 3/4 hard this shaft is tough and dulls tools pretty quickly.

Final drill size for tapping.

Even on the lathe I start with a taper tap to help with starting a straight thread.

Then finish with a plug or blind hole tap.

Chamfer the hole edge for a nice touch.

The bit/tool is pointing at the bit I use. The part #'s are McMasters.

Face the edge

Now cut down for the inner race. I cut down to leave about 0.005" shorter than the inner race. This gives enough for the washer to press down on the inner race securely whilst giving plenty of support.

I cut down to about 0.001" of final dimension then polish the remaining 0.001" out for a nicer look. The ends are filed on high speed for slight radius so they are not razor sharp.

Fitment check.

Part stack up. The large fender washer acts as a shield for the bearings rubber seal.

This is rough cut comparing it to the old base and master sample pulleys I have. This will become clear in a bit.