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Name That Squeal ???

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Discussion starter · #1 ·
Yes … I took a stethoscope to every moving part with zero luck. I can’t determine where this noise is coming from. I applied silicone spray and initially it went away only to return once I drove it. Hmmm?

It sounds like a pulley but again, zero noise when I put my ear to it. Has me stumped. I’ll be removing the fan belt tomorrow and thoroughly checking things. Just hoping it’s something simple. If it is a bearing, I’m in luck because I have spares!

Any thoughts?
 
#2 ·
Maybe its just the angle of the camera, but it looks like the PS pump pulley is out of alignment with the idler pulley. That could cause a belt to chirp. Its visible at 0.04 of the video

Image
 
Discussion starter · #3 ·
I’ll take a good thorough look at it. Would over tightening the belt cause it? What would cause that pulley to misalign? I did put a couple drops of Hoppe’s in that bearing when I recently cleaned it. There was a lot of grease grime around it on the backside. I’m wondering if I compromised it?
 
#4 ·
The idler misaligned from possible bearing failure, is likely cause of the belt looking like it does.
 
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#5 ·
258 said:
I’ll take a good thorough look at it. Would over tightening the belt cause it? What would cause that pulley to misalign? I did put a couple drops of Hoppe’s in that bearing when I recently cleaned it. There was a lot of grease grime around it on the backside. I’m wondering if I compromised it?
Click to expand...
Loosen the belt and rock the pulley's, basically the same test as for a ball joint. If the bearings are loose, the pulley will rock a hair. You can also turn them by hand and feel for a "gritty" feeling or a roughness that would indicate the bearing is bad.
Overtightening the belt could (in theory) bend the pulleys shaft, but man, you'd have to really crank it to do that. I can't say I've ever heard of it happening myself.
Holding a straight edge across the pulley while turning it will show if the pulley itself is bent.
I didnt notice anything in the video that would make me think it was a bent pulley, none were wobbling or spinning funny, just the angle the belt was coming off that idler showing the two pulleys arent in the same plane.
 
owns 1986 JEEP CJ7 Base
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Discussion starter · #6 ·
ChrisReyn said:
Loosen the belt and rock the pulley's, basically the same test as for a ball joint. If the bearings are loose, the pulley will rock a hair. You can also turn them by hand and feel for a "gritty" feeling or a roughness that would indicate the bearing is bad.
Overtightening the belt could (in theory) bend the pulleys shaft, but man, you'd have to really crank it to do that. I can't say I've ever heard of it happening myself.
Holding a straight edge across the pulley while turning it will show if the pulley itself is bent.
I didnt notice anything in the video that would make me think it was a bent pulley, none were wobbling or spinning funny, just the angle the belt was coming off that idler showing the two pulleys arent in the same plane.
Click to expand...
Last week my belt was super loose; like an inch of flex. I may have super tightened it; in fact, I know I super tightened it, lol. I’ll check all those areas! 👍🏻
 
#8 ·
258 said:
Last week my belt was super loose; like an inch of flex. I may have super tightened it; in fact, I know I super tightened it, lol. I’ll check all those areas! 👍🏻
Click to expand...
I'd have to look it up for a CJ, but most belts should have 0.25 to 0.5 inches of deflection, meaning you can push the belt down that far. They arent supposed to be bow-string tight.
Edit{ if the pulleys are 10-12 inches apart, there should be 1/4" deflection, if the pulleys are 12-14 inches apart, there should be 1/2 inch deflection- per the Chiltons book here next to the desk.
 
owns 1986 JEEP CJ7 Base
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Discussion starter · #9 ·
UPDATE:
Turned out to be a pulley bearing. Checked the pulley alignment; good. Checked the belt tension; way too tight. Removed belt and started it; no squeal. Spun each bearing individually and the one by PS pump was toast.

Also, is it normal for that PS pulley to be so tight to rotate?

I also spun the alternator and it felt too rough. It’s a 10si that’s been rebuild to 94A internals. So I will swap out tomorrow with my 12si that’s been rebuilt to 140A and move forward. I have never installed the 12si; been on the shelf, but looking forward to it. It’s set-up to charge my system at idle. The 10si doesn’t. You need higher fwy rpm’s to get a good decent charge … one of the reasons I trickle charge it regularly.
 
#10 ·
Glad its resolved!! WTG
 
owns 1986 JEEP CJ7 Base
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#13 ·
No it was me............I am the winner!
 
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Discussion starter · #15 · (Edited)
Remove the belt and spin the pulley’s. You will hear a noticeable difference. Loosen as needed.

I had a back-up bearing (6203RS) which is in the freezer right now. I am about to put the pulley into the oven at @ 140° for 10-15 minutes, drop the bearing in place from the freezer.

*** that’s the bearing part number currently installed. Correct me if I’m wrong. Seems like the I.D. may be a tad too large?
 
#16 ·
That's correct. The ID is too big on all the the ones I found. That's why I bought new pulleys. Even the new pulleys bearing's ID was too big but they came with a bushing installed.
 
#19 ·
258 said:
Yes … I took a stethoscope to every moving part with zero luck. I can’t determine where this noise is coming from. I applied silicone spray and initially it went away only to return once I drove it. Hmmm?

It sounds like a pulley but again, zero noise when I put my ear to it. Has me stumped. I’ll be removing the fan belt tomorrow and thoroughly checking things. Just hoping it’s something simple. If it is a bearing, I’m in luck because I have spares!

Any thoughts?
Click to expand...
I have a 93 XJ that had a noise at start up and went away once it got hot. Ended up being the harmonic balancer.
 
Discussion starter · #20 ·
UPDATE:
New bearings and realignment. Honestly, it was actually a long dragged out morning tackling this. I dropped items 5X’s and unfortunately it took over 20+ minutes to find each one of them. One of the bolts actually rolled into the hedge, grrrr. Very odd!

I had to Dremel a bit because the OEM flanged washers were old and tired. They were showing fatigue. That wasn’t fun!

Also, oddly enough, the fan belt I previously had installed ended up too long. WTF? I swapped it out for one of my older spares and BAM … perfect fit. I have no idea why and how that happened. At any rate, it’s done. On to the next ordeal!

 
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