C2 BB water pump shaft length

[Thomas R.]

I have 67 L36 with AC and PS. When I started to fit the water pump pulley, the pulley rubs against the top edge of water pump. I check the water pump casting and it is 3856284 which according to Corvette by Numbers book is correct. The water pump pulley casting is 3889372 which according to AIM is correct.

I bought repo stiffener/reinforcement plate from LI Corvette which look a little thin but assume it is correct. Also, checked that pulley was not bent which it seems ok. At his point, I'm run out of options other than the shaft or mounting plate is incorrect on the water pump which was rebuilt by someone before I got the car. Also I have not installed the belts to check to see how out of alignment they are if at all.

Any other ideas what I might check ?

[Joe L.]

Re: C2 BB water pump shaft length

I have 67 L36 with AC and PS. When I started to fit the water pump pulley, the pulley rubs against the top edge of water pump. I check the water pump casting and it is 3856284 which according to Corvette by Numbers book is correct. The water pump pulley casting is 3889372 which according to AIM is correct.

I bought repo stiffener/reinforcement plate from LI Corvette which look a little thin but assume it is correct. Also, checked that pulley was not bent which it seems ok. At his point, I'm run out of options other than the shaft or mounting plate is incorrect on the water pump which was rebuilt by someone before I got the car. Also I have not installed the belts to check to see how out of alignment they are if at all.

Any other ideas what I might check ?

Thomas-----

The measurement from the face of the hub (i.e. pulley seating surface) to the block mating surface of the pump should be 5-3/4".

[Thomas R.]

Re: C2 BB water pump shaft length

Did the measurement, little awkward, but it is 5 3/4in.

[Joe L.]

Re: C2 BB water pump shaft length

Did the measurement, little awkward, but it is 5 3/4in.

Thomas-----


It needs to be a fairly precise measurement; if you're off by 1/16" that could be the problem.

Does the pulley contact the pump housing through 360 degrees of rotation or does it contact only at certain points of full rotation?

[Thomas R.]

Re: C2 BB water pump shaft length

Thanks Joe for the help, it is a consistent rub throughout the 360 rotation. It is ever so slight, but noticeable. Another NCRS friend said he has about 1/4 inch gap between the two

[Joe L.]

Re: C2 BB water pump shaft length

Thanks Joe for the help, it is a consistent rub throughout the 360 rotation. It is ever so slight, but noticeable. Another NCRS friend said he has about 1/4 inch gap between the two

Thomas----


Once you're sure of the hub spacing dimension that I mentioned previously, then about all you could do is to grind the waterpump casting for clearance. This assumes that the pullies line up, as-is. If the pullies don't line up and require moving the hub further outward, then that will solve BOTH problems.