[T3] Whining noise with new gen belt

Phil Hof phil.hof at ostronic.org
Mon Sep 22 21:17:19 PDT 2014


I read on there Samba, after a search for “whistle” and “belt” and found that some believe the cogged belts make such a noise.  Yep, my new belt is cogged.  I’ll try some other belt(s) to see if the noise goes away.  I also sourced a replacement pulley so I won’t worry about cutting a new belt.

Still go the flickering red oil light after the drive home.  No morning startup noises, though.  I know I have excessive endplay when I took it down to the short block a few years ago (for cleaning).  I re-shimmed but didn’t want to make a sudden drastic change, and got it close with three thick shims.  It’s another item to take care of soon as part of a teardown.

I will add that I use LED dash lights, so there is zero lag in the light.  Rather than a dim light, I get a fast flicker, and it is instantly full brightness.  I like that even in broad daylight I can immediately see the light.  Well, I’d prefer NOT to see the light, but that’s a different matter! ;-)

-Phil

>> A new noise appeared with the new belt.  It?s a high-pitch whistling that is at generator speed.  Anyone had this happen?  I have a few theories:
>> 1) The new belt has a surface that needs to wear-in/work/stretch, and the noise will go away.
>> 2)  I need generator bearings.  But I?ve had then fail before and this is not the noise.
>> 3)  This is the interesting one:  the halves of the pulley are worn.  There are ridges and it is definitely shaped in a wear pattern.  You would not expect metal to wear when pushed on by rubber, but I suppose after a hundred billion or more revolutions anything will wear.  I wonder if the belt is being squeezed as it moves around the worn pulley, slipping into the worn part, then sort of oepopping out? of the groove as it exits the pulley during rotation.  Maybe that is the noise?  I canTMt see any easy way to machine it  smooth, and even if I did, it would be weakened from being thinned.
> 
> I've heard 2 different noises from generators: bad bearings and dirt 
> on the field pole pieces that builds up to the point where it rubs on 
> the rotating commutator. I've never heard belt noise like you 
> describe, but it's possible since your new belt is probably riding on 
> a partly worn/partly new area of the pulley. I'd look for a different 
> belt anyway; something like 10 x 1005 or 10 x 1008, or 3/8 x 39.5".
> 




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