Diesel Place banner

Symptoms of failing harmonic balancer

63K views 30 replies 15 participants last post by  bondjames85 
#1 ·
Can anyone tell me what the symptoms of a failing harmonic balancer are? I want to replace it, but i won't have the money for a few months. I just want to know what to look for.

I have read to check to see if it's cracked etc, but how the heck can you see it? I can't see inside of it looking down.

Right now i have a strange bird chirping noise that I can't find coming from the engine. I think it may be the a/c compressor, but not sure.
 
#3 · (Edited)
that wasn't very helpfull Jason.

you pretty much need to take the belt pully off to really see it

read this thread for info. http://www.dieselplace.com/forum/showthread.php?t=78419

chirp is most likely AC, disconnect the plug for it at the clutch, if the sound goes away, you've found it
 
#6 ·
O have one when I start my truck it vibrates at idle then when I give it rpms it gets more at around 2800 rpms when driving it's gone at 60km and back any were past 80km I have checked the tc and all bolts are still tight any other sugestions I'm leaning toward tje harmonic balancer my self any sugestions would be great and sorry for spelling mistakes I only have my iPhone or a computer
 
#13 ·
I just bought a 96 GMC Sierra with the 6.5. This is my second one. The first one I owner was over 7 years ago. I 'm getting the same vibrations at idle to. When I first got the truck it was making a clunking noise, It was the pully infront of the banlancer the mechanic told me. The clunking noise went away after the pully was replaced but I just have the bad vibration now, in till I get above 1500 to 2000 rpms. Can someone help me with this Its driving me nuts. Is it the balancer? Thanks. Ted
 
#7 ·
Can someone discribe this clunking at shutdown a little more to me? thanks
 
#8 ·
And I'd like to know what specifically to look for as far as visual inspection.
 
#9 ·
You will know it because it shows sign of disintegration to put it mildly.

Those thing are rubber so what does rubber do when it is going to fail?
 
#10 ·
Ok so the whole thing is rubber? I thought only the inside was. So as long as it looks solid its good to go?
 
#11 ·
Pull off the belt and see if you can move the pulley /
balancer by hand, if no play or wobble, you're probably
OK for now
 
#12 ·
I replaced mine just to be safe and found out it was bad. I had a bird chirping sound when running that I thought was the AC compressor. When the HB was pulled it slid right off by hand. The noise turned out to be the HB having play in it. New HB pressed on and no more noise.
 
#14 ·
If you replaced the pulley, then there is a very good chance the balancer is bad and causing the problem. Regardless, you should not even start the motor untill you replace that balancer. You could snap your crank if it is the balancer.
 
#16 ·
Bad Pulley:





And what it sounds like running,

A little hard to hear over the other 6.5 noise, but if you listen you can catch the "clunking"




My old Balancer VS New...

 
#17 ·
was your old one bad? Just curious cause the rubber on mine isn't coming apart but it is squished like that.
 
#18 ·
As bad as my pulley was I didn't want to risk not changing out the balancer. I don't think it was *bad* it was just well worn.

With the problems these motors have with cranks I wouldn't keep a factory balancer in for more than 100k.
 
#19 ·
I have no vibration but I'll probably change it. Hopefully it will be ok for another couple months cause I'm broke till then.
 
#20 ·
i just got the same vibtation at idle! my trucks never seen 2800 rpm since i owned so i dunno about that but yeah i nspected my pulley rubber and it shows small 1/8 inch stress marks in it lots of the, they look like little cracks on like a 45 degree angle so i think im goingto replace it this week ill post when i know more.........just fyi im a procrastinator so iplan on changing it this week but.....
 
#21 ·
I had the clunk at shutoff... I replaced the crankshaft pulley and the harmonic balancer and the clunk went away.

The HB seemed to be in decent shape, but the pulley's outer rim had separated and was clanking against the metal stop.

So I could have gotten away with just replacing the pulley, which would have been a very easy job. But I took the advice of the folks on here and replaced the HB too.

It wasn't as easy as the pulley... but not too impossible.

I got my dad to help by keeping the engine from turning through the tranny inspection port.

Hope this helps.

More later...

Z.
 
#22 ·
I'm in the middle of replacing my crankshaft pulley / harmonic balancer right now. I noticed that the pulley moves and actually disformed the bolts that held it on? Is this normal? Also, how did all of you guys keep the engine from cranking over when trying to loosen and tighten the bolts that hold the balancer on and the crankshaft pulley on? Thanks.
 
#25 · (Edited)
I'm in the middle of replacing my crankshaft pulley / harmonic balancer right now. I noticed that the pulley moves and actually disformed the bolts that held it on? Is this normal? Also, how did all of you guys keep the engine from cranking over when trying to loosen and tighten the bolts that hold the balancer on and the crankshaft pulley on? Thanks.
Ratchet strap...



My bolts were a little boogered up to, but I reused them. They have worked fine.

 
  • Like
Reactions: 101Volts
#23 · (Edited)
I used a screwdriver in the flexplate to keep my engine from moving. As far as bolts being deformed no its not normal. Its probably an indictator that they were left loose at some point and reusing them could cause them to fail.
 
#24 ·
I had three symptoms:

A/C quit putting out cold air.
Loud ticking sound (thought I had a cummins)
Loud "clunk" when I turned it off.

Seemed to run fine.
 
#26 ·
Where should one get the pulley from, GM dealer or auto parts? not sure if i trust the AP stores parts on something this important.
 
#27 ·
You cannot buy the pulley from an auto parts store. It is a dealer item. I did however (with some help from fellow dieselplace followers) found that they sell them at RockAuto.com. I purchased mine yesterday. It was $62 shipped to my door. That's better than the $155 that the Chevrolet dealer wanted.
 
#29 ·
I got mine at CarQuest

The only catch was that the pulley was also called a "balancer" but thankfully they have pics on their parts database so I was able to figure out what to order!

 
#31 · (Edited)
I'd tell you if I could remember! :)

It didn't seem like it was all that bad, $65 or something...

Also on RockAuto.com

ATP Part # 102106 for $52 for Pulley
ATP Part # 102051 for $50 for Balancer
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top