1969 Crank & W/P Pulleys

[Michael B.]

I just got finished stripping the paint off my crank & water pump pulleys and I see that they are black phosphate finished. Can I assume that when a part, any part, is phosphate finished that it was not painted?

[Joe L.]

Re: 1969 Crank & W/P Pulleys

I just got finished stripping the paint off my crank & water pump pulleys and I see that they are black phosphate finished. Can I assume that when a part, any part, is phosphate finished that it was not painted?

Michael-----


Yes, someone must have painted your pullies. Pullies were either painted black or black phosphate-finished. Sometimes, the same pulley part number may be found with either of these finishes. I believe the GM specs provided for either finish optionally. Original pullies from the 60's and early 70's are often found with black phosphate finish, although some were painted. Virtually all the SERVICE pullies available in the past 20 years, or so, including all those of the original part number and still available, are painted or powder-coated black.

I've never seen a case when an original pulley was painted over black phosphate. Of course, if it ever occurred we'd probably not know about it, anyway, since it would not be readily apparent. However, there would have been absolutely no reason for a manufacturer to use both finishes. It would have added significant cost and was not required.

[Jack H.]

Re: 1969 Crank & W/P Pulleys

The only explanation for dual coatings that I can fathom would be 'scrap recovery' by the mfgr and/or GM to make parts that were originally plated with insufficient coverage and/or handling surface damage 'useable' again. But, that's a stretch, eh?