harmonic balancer?
Thread Starter
Advanced
Joined: Aug 2002
Posts: 61
Likes: 0
From: Toughkenamon, PA 19374
harmonic balancer?
It's been about 20 degrees lately and I decided to start the old 85 C4 up. I let it run for about 15 minutes. When I went back outside I noticed a vibration at 12-1300 rpms. I could feel the vibration come and go about 2 seconds apart. Any ideas ? How could I check the balancer? thanks...Jim
7th Gear
Joined: Jan 2003
Posts: 7
Likes: 0
From: Bellevue WA
Re: harmonic balancer? (jimsmith)
Jim,
Hook up a timing light to see if you can get a mark (and see if your mark is moving up and down).
To quickly check, grab the outer ring and see if you can turn it. I just replaced mine and that's what I did to determine it was bad. I was lucky to replace it when I did, once it was off, I could turn the outer ring with little effort.
If you replace it, get a good puller/installer (non jaw type). That will make your life alot easier (on/off took me about 35 minutes).
Changing out the HB was and is only part of my vibration problem. Next is having the clutch balanced to the flywheel.
good luck!:cool:
Shawn
PS - also check our motor and tranny mounts. I replaced all and found out the left side motor mount was broken. :eek:
Hook up a timing light to see if you can get a mark (and see if your mark is moving up and down).
To quickly check, grab the outer ring and see if you can turn it. I just replaced mine and that's what I did to determine it was bad. I was lucky to replace it when I did, once it was off, I could turn the outer ring with little effort.
If you replace it, get a good puller/installer (non jaw type). That will make your life alot easier (on/off took me about 35 minutes).
Changing out the HB was and is only part of my vibration problem. Next is having the clutch balanced to the flywheel.
good luck!:cool:
Shawn
PS - also check our motor and tranny mounts. I replaced all and found out the left side motor mount was broken. :eek:
Drifting
Joined: Sep 1999
Posts: 1,908
Likes: 0
From: Manassas, VA, USA
Re: harmonic balancer? (Shawn's 78)
Jim,
Hook up a timing light to see if you can get a mark (and see if your mark is moving up and down).
To quickly check, grab the outer ring and see if you can turn it. I just replaced mine and that's what I did to determine it was bad. I was lucky to replace it when I did, once it was off, I could turn the outer ring with little effort.
If you replace it, get a good puller/installer (non jaw type). That will make your life alot easier (on/off took me about 35 minutes).
Changing out the HB was and is only part of my vibration problem. Next is having the clutch balanced to the flywheel.
good luck!:cool:
Shawn
PS - also check our motor and tranny mounts. I replaced all and found out the left side motor mount was broken. :eek:
Hook up a timing light to see if you can get a mark (and see if your mark is moving up and down).
To quickly check, grab the outer ring and see if you can turn it. I just replaced mine and that's what I did to determine it was bad. I was lucky to replace it when I did, once it was off, I could turn the outer ring with little effort.
If you replace it, get a good puller/installer (non jaw type). That will make your life alot easier (on/off took me about 35 minutes).
Changing out the HB was and is only part of my vibration problem. Next is having the clutch balanced to the flywheel.
good luck!:cool:
Shawn
PS - also check our motor and tranny mounts. I replaced all and found out the left side motor mount was broken. :eek:
Follow Shawn's advice to the letter, and you should be able to zero in on it.
:cheers:
Le Mans Master
Joined: Aug 2000
Posts: 6,362
Likes: 7
From: Brazos TX
Cruise-In IV Veteran
Cruise-In V Veteran
Re: harmonic balancer? (jimsmith)
Just a visual inspection can reveal a lot. You may see the balancer is crooked or loose. Removing the crank pulley may be a good idea so you can see it well. Placing a stripe on the outer ring and on the pulley will let you know if the ring is slipping. Mark it, then run the engine, then check the mark.
