AMC Eagle Den Forum

The Mighty 258 => The Engine => Topic started by: shanebo on January 08, 2012, 12:31:57 AM

Title: Anyone ever had a bad harmonic balancer?
Post by: shanebo on January 08, 2012, 12:31:57 AM
Ive been in the process of tracking down a vibration in my sx4. Someone suggested it could be the harmonic balancer, Has anyone ever had one go bad on their Eagle...or any car for that matter? I am just curious what the syptoms were.

Thanks
Shane
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: IowaEagle on January 08, 2012, 08:49:36 AM
Yes they do go bad, regardless of brand/make of the engine.  The rubber part between the two steel parts gets weak or is damaged during an improper R & R session.
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: mudkicker715 on January 08, 2012, 12:28:20 PM
On a 351w it spun apart and shook lik h e l l.
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: txjeeptx on January 08, 2012, 01:32:38 PM
Yes, I've had one go bad on my 4.o in the MJ. It didn't vibrate much, but it would squeak. The rubber had failed between the hub and the pulley part, and the two could move a bit independently, caused the serpentine belt to be out of alignment with the rest of the system, so it would chirp. New balacer solved the problem.

Also replaced the balancer on my FSJ's 360, and it smoothed it out a bit. The rubber was swelled due to engine oil leaking on it. Replaced crankshaft seal at same time with balancer on both the FSJ and the MJ. No more leaks at the front of the engine.
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: Sunny on January 08, 2012, 06:36:50 PM
My dad's Olds V8 had it actually wear the keyway so it was shaking like crazy. We pulled it off and threw a new one on. Vibration stopped, and it ran a lot better.
It was the original one though, so I can't say too much about it.. hah.
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: shanebo on January 08, 2012, 09:51:05 PM
would the harmonic balancer cause a vibration when the car is reved in neutral too, or does the engine need to be under load to get the full effects?
Title: Re: Anyone ever had a bad harmonic balancer?
Post by: carnuck on January 08, 2012, 10:14:26 PM
Any time the motor was revved, but worse in gear. Every AMC I've had with auto trans (9xx series) that vibrated suddenly or progressively worse that wasn't the harmonic balancer, it turned out to be the neck of the torque converter starting to crack or the lockup clutch inside falling apart and throwing the balance off. Especially if the motor had even compression (one pushrod bent would make a vibe too)