Author Topic: Problem with new pulley ???  (Read 797 times)

DAVEN1256

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Problem with new pulley ???
« on: January 14, 2020, 03:09:09 AM »
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








169INDY

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Re: Problem with new pulley ???
« Reply #1 on: January 14, 2020, 04:14:58 AM »
Take it to your local machine shop and they can chuck that thing up and zip off 0.062" in a hurry.
Touch up paint and bolt it on an go.

Neat it was avail at all.

Jim
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS
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rszmjt

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Re: Problem with new pulley ???
« Reply #2 on: January 14, 2020, 02:07:55 PM »
I doubt it would be a issue, I’ve used this pulley lots on Corvettes, never a problem. If you were super concerned about belt alignment you could shim the lower PS cradle bracket forward a similar amount with a couple of washers.

Sauron327

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Re: Problem with new pulley ???
« Reply #3 on: January 14, 2020, 09:43:32 PM »
The base of the power steering pulley bottoms out on the double pulley bottom. If the lip held it out 1/16", they would not seat correctly.

DAVEN1256

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Re: Problem with new pulley ???
« Reply #4 on: January 17, 2020, 12:57:29 AM »
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 tightenein

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.




67CruiseMaster

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Re: Problem with new pulley ???
« Reply #5 on: January 17, 2020, 01:06:06 PM »
I have found that the radius on the 2 dimpled holes prevent from fully seating. Look and see if the holes on steering pully are open enough to fit over that radius. If not, then consider either opening them up a little or looking for another pulley if it doesn't work.

Scot
67 SS/RS with original Cruise Control
67 Tuxedo Black Convertible.

KurtS

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Re: Problem with new pulley ???
« Reply #6 on: January 18, 2020, 04:55:01 AM »
That's one of the first pulley failures I've ever seen. I'd get a used one....
Kurt S
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DAVEN1256

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Re: Problem with new pulley ???
« Reply #7 on: January 25, 2020, 11:54:21 PM »
Thanks for all the replies and thoughts on this.

I sent the new pulley back for a refund and one of the members here 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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