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-   -   PS pulley problem (https://forums.maxperformanceinc.com/forums/showthread.php?t=885671)

02CiC 05-31-2026 03:39 PM

PS pulley problem
 
Hi all. Removed the PS pump for a swap, as the belt was heating super noisy. Belt replacement didn't help (although the old belt was beat up). Used a pulley pull tool to remove the old pulley. Bought a replacement pump from Classic Industries but neither the original NOR the replacement pump has threads in the center of the shaft for the pulley installation tool to attach to. The old and the replacement pumps and pulleys have slots for the woodruff key and they are aligned, but I can't get the darned pulley on either pump. Help!

SRGN 05-31-2026 07:27 PM

The internally threaded shaft is only for press fit pulleys IIRC. Sounds like you have a press fit pulley and pumps designed for a retaining nut/keyway style. Post pics if you can.

02CiC 05-31-2026 08:33 PM

Quote:

Originally Posted by SRGN (Post 6618274)
The internally threaded shaft is only for press fit pulleys IIRC. Sounds like you have a press fit pulley and pumps designed for a retaining nut/keyway style. Post pics if you can.

Thank you! The guy at the garage down the street managed to shimmy it on, worked like a charm! Now the issue is the power steering still squeaks like crazy. Replacing the pump and belts had no effect. I can see when it's squeaking that the pulley stops turning abruptly with each squeak. The Internet says that I may need a new pulley, but why would my pulley have become misaligned or out of round, or dysfunctional before doing anything to the belts or pump? In other words, why did this thing start squeaking after 20 years of ownership and flawless, mechanical function.?

SRGN 05-31-2026 09:59 PM

I'll try to get some pics tomorrow, I have a couple of Pontiac PS pumps for reference. What fluid are you running? It's possible that the valves or ball assembly in the steering box are stuck/damaged and causing a fluid blockage.

02CiC 06-01-2026 03:25 AM

3 Attachment(s)
Quote:

Originally Posted by SRGN (Post 6618296)
I'll try to get some pics tomorrow, I have a couple of Pontiac PS pumps for reference. What fluid are you running? It's possible that the valves or ball assembly in the steering box are stuck/damaged and causing a fluid blockage.

I was afraid of that. Dexron III

73ta 06-01-2026 10:44 AM

You need a wider PS belt so it rides at the same height as the other belt in the pulley. They are trying to go different speeds. Pontiac specked a wider belt for PS on some late 60's engines. I just went thru this on my 455.

02CiC 06-01-2026 11:55 PM

1 Attachment(s)
That would be amazingly simple. Here's what I bought from Autozone. Where and how would I get a wider belt?

The one I bought in the attached pic is 0.44" wide. Autozone has one the same length in their 17 series that's 0.53" wide. Classic Performance only sells one that is 0.469". Wondering which to get.

johnta1 06-02-2026 06:48 AM

Originally the belt widths were 3/8" (.375") for alternator and 1/2" (.500") for the PS. (I think anyway)


Now they are probably made metric.
Try and get close to the widths for each one might help?


:confused:

73ta 06-02-2026 11:30 AM

Quote:

Originally Posted by 02CiC (Post 6618451)
That would be amazingly simple. Here's what I bought from Autozone. Where and how would I get a wider belt?

The one I bought in the attached pic is 0.44" wide. Autozone has one the same length in their 17 series that's 0.53" wide. Classic Performance only sells one that is 0.469". Wondering which to get.

Get the 0.53" wide belt.

Here's what I'm using on my 73 455:

Vbelts

Alternator: Gates 7490 – 49.0”

Power Steer: Gates 9530 – ½” X 53.375”

AC: Gates 7585 - 58.5”

02CiC 06-03-2026 10:05 AM

Quote:

Originally Posted by 73ta (Post 6618482)
Get the 0.53" wide belt.

Here's what I'm using on my 73 455:

Vbelts

Alternator: Gates 7490 – 49.0”

Power Steer: Gates 9530 – ½” X 53.375”

AC: Gates 7585 - 58.5”

I tried the wider belt but can't get it to go on all of the pulleys. It sits too high. Can I just get a bigger diameter than 51.5"? Only need about another inch or so. Maybe 52.5 or 53"?

02CiC 06-03-2026 12:01 PM

Quote:

Originally Posted by 73ta (Post 6618347)
You need a wider PS belt so it rides at the same height as the other belt in the pulley. They are trying to go different speeds. Pontiac specked a wider belt for PS on some late 60's engines. I just went thru this on my 455.

Forgot to mention that when I replaced the two drive belts, both were the same with, one is part 15500 and the other is 15515. Both are the same brand and the only difference is the alternator belt is 50 inches, and the power steering belt is 51.5 inches in diameter. Do you still think that I should just put a wider belt on the power steering to see if it will stop squeaking and seizing?

73ta 06-03-2026 12:36 PM

Quote:

Originally Posted by 02CiC (Post 6618590)
Forgot to mention that when I replaced the two drive belts, both were the same with, one is part 15500 and the other is 15515. Both are the same brand and the only difference is the alternator belt is 50 inches, and the power steering belt is 51.5 inches in diameter. Do you still think that I should just put a wider belt on the power steering to see if it will stop squeaking and seizing?

Yes, fixed my problems. Factory manual for 1973 shows same width belts, but earlier pre 70 some models used a wider PS belt. My pulleys came from an unknown source. My belts ride at the same height in the double pulley grooves now in my WP and crank pullies. Fixed my belt noise.

Check gates site for belt specs. My PS belt is Gates 9530 – ½” X 53.375” long.

"one is part 15500 and the other is 15515" those are the same series belts, 15 series, and the same width? Pulleys have two different groove widths is my thought.

SRGN 06-03-2026 01:30 PM

Given that it was good for a long time and the issue suddenly came up, I'm inclined to believe it's more than just a belt issue. I'd start with pulling the lines off the box, draining the fluid, and turning the wheels back and forth slowly from lock to lock(wheels off the ground) to get the old fluid out. I would try regular power steering fluid to refill after reinstalling the lines. PS fluid is a little easier to push than ATF given the difference in viscocity. I'm assuming that the issue is occurring at idle, make sure your idle speed is set to spec as well.

02CiC 06-04-2026 02:58 AM

Quote:

Originally Posted by SRGN (Post 6618619)
Given that it was good for a long time and the issue suddenly came up, I'm inclined to believe it's more than just a belt issue. I'd start with pulling the lines off the box, draining the fluid, and turning the wheels back and forth slowly from lock to lock(wheels off the ground) to get the old fluid out. I would try regular power steering fluid to refill after reinstalling the lines. PS fluid is a little easier to push than ATF given the difference in viscocity. I'm assuming that the issue is occurring at idle, make sure your idle speed is set to spec as well.

Thank you for this, it is at idle and also when doing sharp turns at very low speed. In any case, I bought an AX50 Gates belt 1/2" x 52", and it worked like a charm!

I'm so grateful for all the help here, only now wondering if I should have even replaced the pump or tried your belt tricks first. In any case, it feels great to have a sorted car again!

You guys rock!


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