(This is a reprint from my first blog, Sept 2007, of one of Massimo’s most memorable Ferrari stories and one of my favorites as well since I was around and actually saw what had happened, it was fascinating and I thought it was time for a re-share.)
MIA or Missing In Action
A client came in with a blown head gasket due to over heating, on a 1985 308 4 valve Ferrari. Massimo pulled the engine out, pulled the heads off, replaced the head gasket and thermostat. He than checked the water pump and looked through the water pump housing pipe as well, everything appeared fine, no leaks..,
So why had it overheated?
Massimo is meticulous and always double checks everything. And on a hunch, he pulled the water pump cover, but again no obvious reason for the trouble, the shaft had no play on the bearing, seals looked recently done, no problems right?
When he tried to turn the shaft by hand the shaft would spin without consistently engaging the gear. In other words the shaft is supposed to be locked onto the gear so that it doesn’t move at all! First thing he thought of was that the Woodruff key notch, a piece that sits on the key and fits into a spot on the gear wheel, was completely worn out. But when he pulled the front engine cover off and saw the gear bouncing on the shaft he was intrigued.
Moving? He thought, this thing wasn’t suppose to be moving around at all!
After getting down to the Woodruf key itself he saw clearly that there was no notch at all! As you can see in the photo there is nothing attached to the shaft! Instead, the Woodruff key had been pressed in. It is very likely that the shaft came like that from the factory, hard to tell, but because the notch wasn’t milled onto the shaft, the water pump circulated sporadically, which in turn caused over heating and finally catastrophic failure.
So Massimo replaced the water pump shaft and the problem was solved.
But he later confided to me that this was really strange and he’d never seen anything like this in all of his years working.