Pulley alignment question

[Driver_X]

I recently had the seal for the #8 bearing replaced, when I went to the shop the mech asked me if my alt had always made that noise, it sounded like the bearings were ready to go. I couldn't recall the noise specifically, but I had just come back from 4+ hours of driving back & forth to hershey, and it was a used Alt so I figured why the heck not, it was possible. I had a rebuilt unit in the basement and had planned to install it anyway so that's what I did. Installed it yesterday and I have the same noise, sort of like birds chirping. Upon closer inspection, it sure seems like the crank pulley and fan don't line up. The crank pulley appears to be about 1/8" inboard of the fan pulley and belt is making the noise.

So my question is, by removing and reinstalling the crankshaft pulley to replace the #8 bearing seal, are there any washer or shims that could affect the pulley alignment if not reinstalled correctly? Or, what would cause a sound like birds chirping if not the alternator itself as I can't believe that newly rebuilt alt would sound exaclty like a well used version. FWIW the used version seemed to spin smoothly, although not as smooth as the rebuilt unit.

Thanks all for you input....

[gregwils]

You may want to ask about the #8 pulley on the engine rebuilding forum. I have only had mine off once, so my memory is a little vague. However, I don't think there are any shims. I would have to look back through Wayne's engine rebuild book to see if he mentions it if no one else responds.

Here is a picture of the end of the crank at the #8. You can see the seal that fits around the end of the crank at the #8 bearing. That is what he should have replaced. The pulley....to the best of my recollections....bolts directly to the end of the crank, no shims or washers. You can see the bolt hole in the middle of the crank. I don't think it's possible to invert the pulley, but if it is, that would cause misalignment. I might be inclined to take it back to the mechanic and tell him what you think you found. He should be willing to address any issues that didn't exist before his work.

[Driver_X]

Thanks for the response and picture. I'm going to try and swap out the belt and see if the sound goes away.

I'm also going to call the mechanic in the morning and report what I found after the alternator switch. Perhaps he'll have a direction for me to head in to track down the noise.

Thanks again Greg....

[SC Jim]

Please let us know what you find out. I am experiencing what sounds like the same thing after alternator and pulley replacement and it has been driving me crazy. Thanks!

[Grady Clay]

Yes, this can be the alternator bearings failing.
You may ask “Why now?” but it may simply be that a properly tensioned belt has ended the life of a decades-old bearing.


There can be another possibility.
It is not uncommon for the outer pulley half not be firmly seated against the shim washers between the pulley halves.
This allows the outer pulley half to ‘wobble’ as the fan rotates making the ‘chirp’ sound.
Eventually (but not a long time) this will damage the outer pulley half and the fan hub.

Remove the outer pulley half and inspect the flats on the hub and pulley half for shiny spots or damage.
Be sure there are a total of six shims.
Inspect the ‘cup washer’ that it is not deformed.
With too few shims and/or a deformed cup washer, the nut can bottom on the threaded shaft, not allowing compression of the stack of cup washer, shims and pulley half.

Best,
Grady

[Rot 911]

The "birds chirping" sound may be a fan blade hitting the fan housing. You both mention you had the alternator replaced. These fan housings can get cracks in them over time and possibly when the alternator was replaced the mechanic overly tightened fan housing strap causing the fan housing to become slightly oval in shape allowing the fan blades to hit is a few places on the housing. Loosen up the strap enough to take tension off the housing and see if the noise goes away.

[Driver_X]

When my mech replaced the pulley, he put the 4 shims on the inside and neglegted to replace the two on the outside. It took some deep thought to realize this error...sometimes you can't see the forest through all the trees. I am patiently waiting for 2 shims to come via mail from a thoughtfull pelicanite and once I add them to the outside of the pulley, am hoping this will have result I'm wishing for. I will report back once I get the shims on, hopefully this afternoon, otherwise it'll be next week....

I am a little dissapointed and more than a little angry at my mech for this obvious oversight, needless to say he will not be getting more work from me. Seems he's more interested in the modern variants than us lowly vintage guys....there are plenty of other places to choose from, just none as convenient.

Keeping my fingers crossed this is an easy fix....

[Grady Clay]

Greg,

Here is a good thread:
Pulley Shims, Wrong Config?

If your cup washer is deformed, you can add one or even possibly two more shims to prevent any bottoming.
Here, the limiting factor becomes the nut threads fully and completely engaged (threaded shaft at least flush with the side of the nut).


In addition to a fan belt, it is wise to add to your road ‘spare parts kit’ a pulley half, the cup washer, 8-10 shim washers and a spare nut.

EDIT: Knowing that it was run with a loose pulley half, be sure and inspect the flats on the pulley half and the matching flats on the fan hub for damage (red arrows here).
If there are any signs of damage, the queation always is: "How much is too much?"
Please post some images. The images I posted are extreme damage.

Best,
Grady

[s_morrison57]

Good tips Grady, Driver_x what shop was it so other guys don't have the same grief.
Finn

[Driver_X]

Got the two shims in the mail today from jbell959, many thanks John!!!!!

Put it all back together and it's perfect, not a sound. Everything lines up perfectly.

I feel stupid now...always, always start with the basics.


Grady,

Thanks for your input, when took it apart today, I looked for those wear items and sure enough I have both wear on the pulley 1/2 and a crushed washer. I have ordered new one's of both and will be replacing them as soon as they arrive. My old one's aren't really bad and will go into the bag as extra's just in case.

Many thanks for all of the input, check those shims boyz, check those shims.....

[dshepp806]

Wow,..if that shop doesn't know the shim count/config, what the hey else do they NOT know?

Glad you found it.......what in the world did the wrench say, once you told him?

BEST!

Doyle

[Driver_X]

The shop I went to, the owner & mech is very involved with the PCA, which is one the reason I went there. He primarily works on the water cooled stuff, but has had some air cooled early cars in the shop while I've been there for cars & coffe and DE tech session. Besides, he's about 30 minutes from here, where as my other choices would be over 90 minutes away. There are some closer shops, but haven't heard great things about them so I'm not putting them on my list. There is a PCA event at his shop in a couple of weeks, and if I don't get a chance to get up there before hand, I'll talk to him then, because I'm sure he'll ask me about it. His response should be an intersting judge of his character....imo.