Chasing the banshee...

[Grimor]

I don't really need advice, but i figured I'd start a thread about the annoying squealing from the engine. Had an occasional chirp before the oil change, after i decreased the engine it started squealing constantly. replaced the basics first, idler and tensioner pulley.

no good. power steering, alt and ac spin easily by hand. sound doesn't change when the ac compressor kicks on. with the belt off, no noise.

i hit the alt with a little bit of silicon and the pitch changed so pretty sure it's the alt. next easiest to change anyway.

before i do the alt, I'll probably take the fan off just to make sure it's not the clutch.

 

[littleblazer]

Tip from BlazingTrails I tried that worked, put a dab of die electric grease on the belt. Since it stops a squeaking belt that'll rule out if it's just the belt or not. [emoji106]

 

[Sparky]

When my alt bearings went bad the pulley spun easily by hand but I could hear and feel a roughness that just didn't seem right.

 

[Mooseman]

Mine had an annoying squeak but the alt was otherwise fine. Took it apart and replaced the bearings. Went to a local bearing shop and they had exact replacements. Saved a couple hundred on a rebuilt alt.

 

[Grimor]

Mine had an annoying squeak but the alt was otherwise fine. Took it apart and replaced the bearings. Went to a local bearing shop and they had exact replacements. Saved a couple hundred on a rebuilt alt.

there's a thought, my alt is charging fine, a new bearing might just be the ticket

 

[Mooseman]

There are actually two bearings but it's the smaller rear one that usually fails.

 

[Sparky]

I thought about just rebuilding my alt as it worked OK, but I had no clue where to get the parts and I needed to be at work the next day, so I just swapped it.

 

[AtlWrk]

Do you happen to have the bearing part numbers and/or size?

As it's my only vehicle, I'd have to have the part on hand before starting this.

 

[Mooseman]

The front (larger) bearing is NSK B17-102DG46. The rear (smaller) one is NSK 6202-DU. They don't have to be NSK but specify that they will be going in an alternator so a high heat application.

Got these numbers off another old alternator.

 

[AtlWrk]

Interesting, those NSK bearings cross reference to 6303 (17x47x14mm) and 6202 (13x35x11mm) bearings, respectively.

Interesting note about the high temp. Did the ones you pull have rubber seals? I ask because when I specifically add high temp to the search I get back bearing with stainless steel shields (and high temp grease) instead of rubber seals at 3x the cost.

Also worth noting, 6303 is the same size as the idler pulley bearings (at least the ones I had).

 

[Mooseman]

They had rubber seals, both sides.

 

[Grimor]

i had to drive the truck so i hit the belt with some silicone spray, sound went away briefly

 

[littleblazer]

How briefly? 15 minutes?

 

[Grimor]

completely for 10, then chirping after that for a few minutes until turned off.

when i drove it, chirping and then a decent squealing after a few minutes. especially at higher rpm. back to the (normal) chirping after about 20 miles.

 

[littleblazer]

You put it on the ribbed side correct?

 

[Grimor]

yup

 

[littleblazer]

Sounds like it's just the belt to me. How old? If it's pretty new I say just do the dab of die electric grease like I said earlier.

 

[Grimor]

I'll hit it with some tomorrow, still have the trailer attached so need to drive it anyway to park it.

 

[littleblazer]

Rub the ribs with a dab about the size of the metal end on a pencil. It should cover an area about an inch wide and all the ribs. Run it for about 10 seconds and no more noise. Haven't had to re apply yet.