New water pump idler pulley

[qkcuda]

My 66 has factory air, so the water pump belt runs off an idler pulley. The bearing in my original pulley felt pretty notchy. The new one I got had a machined pulley while the stock one was stamped steel. It had a considerably wider groove than the stock one too, almost like it was for a wider belt like the power steering pump uses. I measured the depth of the belt at .300. With the belt seated in the pulley it measured .120 below the edge. I measured the depth of the groove and it was .520. That means I have .100 clearance before the belt could bottom out, so it should be fine. I had to get the special shouldered and keyed bolt out of the old pulley. It looked like the cover was spot welded in two places, but after I drilled them out it wouldn't budge. I decided to just grind the edges until I could pop it loose, not elegant but it worked. I thought I should post this in case anyone else runs into the same problem.

 

[R413]

I have that wide pulley on a car I bought. Works just Fine.

Mancini sells the pulley that looks like yours
Engine Idler Pulley

And the whole thing that looks factory
Mancini Fan Belt Idler Bracket & Pulley Assembly

You can save a smooth original one by servicing it. Take the unit off the engine. unbolt the pulley and spindle from the bracket. Then remove the plastic cover from the bearing. Clean it out thoroughly and dry it. Now pack with new wheel bearing grease.

 

[qkcuda]

Nice to hear it works fine. I just wonder, it has a shoulder on one side that the outer bearing race seats against. On the stock one it was on the inside, so that is the way I put it together. Is that the way yours is installed?

 

[R413]

Not sure, I never took it apart.

 

[qkcuda]

Makes sense I guess, because the bolt is pulling the bearing up against the shoulder.