That was until about 3 weeks ago when I noticed that the pulley appeared a bit further forward to where I thought it should be. I had never previously been able to see the pulley shaft or the felt seal that sits between the pulley and the timing cover, but I could now.
Alarm bells weren't ringing at this stage, but flashing lights may have been in the distance and getting closer.
I measured the clearance at 3/8", and then sought assistance from several Chev web sites. A couple of good mates, Chris from Sydney and Grant from Gippsland confirmed that my pulley should have a clearance of around 3/16".
What could have caused this after the pulley had behaved perfectly for the last 36 years?
I had seen several postings previously on the web about the same problem, but did not give it a second thought as everything was fine with mine. Since the wedding restoration in 2009, and with the Chev being in a lot better mechanical condition, I had been driving it a lot faster and a lot further.
My conclusion is the pulley coped with 36 years of sedate 35 mph driving, but was slowly moving forward because of the increased cruising speed of 45 to 50 mph, combined with increased vibration from a oil soaked front engine mount. And for all I know it may have been moving over the last year or so.
The shortcut would have been to tap it back into place and hope for the best, but at 58 years of age I am past taking short cuts, in fact I am now dam fussy, and proud of it.
So out comes the radiator for the second time in a month, out comes the puller, out comes the angle grinder to modify the puller and then off comes the pulley.
I measured it with a vernier, and compared to 5 other spares in my cupboard. The one pulled off the car was the 2nd biggest diameter hole out of the lot. So I am glad I pulled it off.
I cleaned up the front of the engine, and thought I would splash a bit of paint here and there seeing I had the radiator off anyway.
Selected the pulley with the smallest diameter hole, cleaned it up, painted it,applied a healthy coating of loctite to the crank and fitted it.
The pulley now sits a lot closer to the timing cover, and the 3 engine pulleys now look more in line.
Also the added bonus that the old pulley had a slight "woof" in it where as the new one runs straight and true.
I don't know guys, nothing lasts. I only put that pulley on the engine in 1974.
Do you think I could put in a warranty claim to GM?
Job done, all back together, looks good, looks square, car happy and Ray happy.
All is well with the world, until the next "event" happens. And as we know there is always an "event" waiting to happen with these old beasts.