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Discussion Starter #1
I have two pulleys on my harmonic balancer. First is the double pulley GM p/n 3744043 for the alternator and smog pump. And in front of that and sandwiched against it, GM p/n 3751232 for the power steering pump.

After having my pulleys sandblasted, I found there was a one inch crack in the alternator groove of the double pulley (3744043) and fatigued metal extending from the crack in both directions. I also found that it was slightly warped. I'm not putting that back on

I saw that this pulley (3744043) was still available from GM Parts Direct, AC Delco p/n 03744043 and ordered one.

The new pulley seems fine and it actually slightly heavier than the original but there is one difference and I don't know if this is going to be a problem or not. My photos will help explain this.

The lip on the front edge of the new pulley sticks out 1/16 of an inch further forward than the original pulley. Because the power steering pump pulley is sandwiched against the new pulley, if I use this new pulley, the power steering pump pulley will be pushed 1/16 inch forward. There isn't much distance between my crankshaft pulleys and the power steering pump pulley. There's only about 6 inches of belt between them that isn't contacting either pulley. So my question is......if I use this new pulley, can that 1/16th misalignment across such a short distance be a problem.....like wearing the power steering pump bearings? Perhaps it's no big deal but I want to be sure.

I know original pulleys are available on Ebay but I would worry about possible getting another one that was fatigued.

Thanks…...Dave







 

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I don't think 1/16 will matter. But, I don't like the lip on the 2 groove pushing the single groove forward. I would remove some of the lip on the new pulley.
 

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Sixteenth-inch isn't bad, but, if losing sleep over it, you could flat washer the pump brackets-to-block moving the pump forward - not the pulley already on the shaft.
Its not the lips of the pulleys being aligned, but the sheaves, what the belts ride be aligned.
 

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Like Everette said you have to keep the belts aligned (about the only use I have ever found for my Sears "our finest" laser level). You can actually put a rule against the middle of the belt and measure how much you need to shim it.

I would not cut that lip down as it was put there to add strength to the pulley (works the same way angle iron works).

Big Dave
 

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It looks to me like it will be fine. Correct me if I'm wrong, but doesn't the back pulley fit completely inside and seat on the inside face making that lip cantilever over?
You can easily figure it out with a tape measure by taking an overall of the pulley's together.
 

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The base of the power steering pulley bottoms out on the double pulley base. If the lip held it out 1/16", they would not seat correctly.
What he said.

If the single pulley isn't seated fully at the base, you have a problem. When you torque the bolts down, it will distort and eventually fail.
 

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Discussion Starter #8
Thanks for all the replies.

I should have mentioned this in my original post but what Scott said about the wider lip on the new double pulley causing the single pulley not to seat properly inside the double pulley is true. When you set the single pulley inside the new double pulley and pull them tight together, there is a 3/64 in gap between the bases of the pulleys. They should actually be contacting each other (see the photo). Despite that gap, the two large holes in the single pulley will still engage the raised lip of the corresponding holes in the double pulley. And yes, I believe that when you tighten the pulley mounting bolts, because of that 3/64 gap between the bases of the pulleys, you are going to distort the pulley.

So I guess my choices are:

1) Send this new double pully back and take my chances on a used one.

2) Have the wider lip on the new pulley machined down to the same width as the original.

3) Use the new double pulley and shim the lower power steering pump mounting bracket so that the power steering pump pulley lines up with the matching pulley on the harmonic balancer.......But I would also have to put washers in-between the double pulley and the single pulley where the mounting bolts pass through them to fill that 3/64 gap so there would be no distortion when tightening.

I'm not sure what the best way is......that might be decided by what a machine shop would charge to trim the lip down on the double pulley.



 

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Are we over-thinking this event?
It's merely remove & replace as taken off.
Is the thickness from the last sheave to pulley mounting surface the same distance?
 

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What he said.

If the single pulley isn't seated fully at the base, you have a problem. When you torque the bolts down, it will distort and eventually fail.
This.....
 

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Very true, remove and take note of disassembly and replace in reverse order.
Make sure all tabs fit into their assigned holes and pulleys fit like before they were removed and tighten the bolts.
Start engine and inspect belts/pulleys as they all work, in alignment, no squealing, and pulleys are straight themselves - no wobbling.
Done, clean up and enjoy an adult drink.
 

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Very true, remove and take note of disassembly and replace in reverse order.
Make sure all tabs fit into their assigned holes and pulleys fit like before they were removed and tighten the bolts.
Start engine and inspect belts/pulleys as they all work, in alignment, no squealing, and pulleys are straight themselves - no wobbling.
Done, clean up and enjoy an adult drink.
It doesn’t fit. It doesn’t seat properly on the base.
 

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True, one has to fit or nest - I like this word Farm Boy - then figure out why and take appropriate action.
Get another pulley or modify the one in hand.
I would not repair original pulley - it will be out of balance and may become wobbly when welded.
PS pulley fits over tabs on crank pulley - holes too small, drill/mill them out to size.

What am I missing, Guys?
 

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If you have a spare harmonic balancer you could bolt the new pulley to it and chuck the balancer in a lathe and turn down the lip on the pulley. This would be cleaner than simply grinding off the offending lip. If you don't have an extra balancer, or know someone with a lathe, a grinder will get the job done. Either way it sucks to have to modify a new part.
 

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Discussion Starter #18
Thanks for all the replies and thoughts on this.

I sent the new pulley back for a refund and one of the members on CRG may have a lead on an original pulley for me. If that doesn't work out and I can't find an original elsewhere, I'll re-purchase the new GM piece and use one of the solutions mentioned above.

Dave
 
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