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| | | | Joined: Jun 2011 Posts: 14 New Guy | | New Guy Joined: Jun 2011 Posts: 14 | Hello all,
Water pump replacement on my 366 went like a snap once I used the right length bolts.
The previous owner used ones 1/4" too short for easy install (2 hours later). Sigh.
Anyways, the pulley is off center.
The 4 mounting holes are slightly larger than the bolts.
HOW do I get this pulley centered on the shaft???
TIA | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Chris_Cozi, are you saying that the diameter of the pulley mounting holes in the in the flange of the new pump are on a larger bolt circle than the old pump? You may be able to elongate the holes to make the old pulley fit the new pump IF you can't find the correct pulley for your new pump, hope that helps. | | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | The pump shaft sticks out of the pump mounting flange a little. The pulley has a center hole/pilot hole that keeps the pulley centered on that shaft. If you do have a stick out shaft and a pilot hole in pulley, that part is a pretty tight fit. The bolt holes in the pulley need to be a bit larger than the bolt to compensate for tolerance. The shaft centers it, the bolts hold it on. That's a normal Chevy mount. What does "pulley off center" mean?
If you don't have what I describe, what do you have?
If holes don't line up, just hold pump tight and rotate the pulley until they do.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Feb 2004 Posts: 29,760 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,760 | If the center hole in the pulley doesn't fit the snout of the water pump, (too big) it's possible the PO has installed an incorrect pulley. If so, you'll need to make a bushing that allows the pulley to center up on the shaft. It doesn't even have to be metal- - - -a piece of PVC pipe or some other type of plastic could be used if you don't have metalworking equipment handy. It just has to be a snug fit on the pump shaft on the inside, and reasonably close to the hole size of the pulley on the outside diameter.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | The pump flange could have a universal multi hole pattern. If you rotate the pulley, you may see a fit. Your motor is weird. Some parts are SBC, some BBC and some either/or. A bastard motor. The water pump seems to be for a BBC. 427, 454.
If the pilot diameter is not snug, Jerry's suggestion is a good idea. Whatever you use as a centering bushing can be removed once the bolts are tight.
If it were me, I would want the correct pump and pulley however.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jun 2011 Posts: 14 New Guy | | New Guy Joined: Jun 2011 Posts: 14 | Thanks all.
Good thoughts.
The pulley is a double wide - I am using the closest to the block for the alternator/flywheel.
Bartamos & HRL: The center hole SEEMS to be pretty dang tight.
The bolt pattern (4) is good and fits in any position.
(The fan is separate from the pulley.)
The water pump fits perfectly and was the TBC 366 match from my service book.
Maybe the pulley was bent/damaged?
Maybe that's why the water pump failed??
More questions than answers, sigh.
;-) Big Bolts - gotta love em!
| | | | | Joined: Feb 2004 Posts: 29,760 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,760 | If the pulley fits the hub and bolts on tight, the only other possibility is a bent pulley. Change it. There are two chances for straightening it- - - - -slim and none. Problem solved!
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | That's why things like "off center" need to be explained. We can't see it from our house. It's not off center. So I guess it's bend. But don't know what you see or when you see it. Take off pulley and check it on a flat bench. Put a bolt and nut in the center hole and spin it on a drill.
You asked "how do I get it centered on the shaft". You now know that it is centered via the tight hole. The pulley or the new pump is bent or spaced wrong. But again we don't know what you see? Wobble when motor running? Belt not straight....like crooked/angled pulley ? Belt not straight.....like offset pulley? Pulley rotating in an ellipse? You can put the pulley on without the fan to watch it with motor running. May need temporary short bolts.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
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