wobbly harmonic balancer - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crm318 · 02-04-2007, 12:06 AM

i currently built a 350 and started it for the first time yesterday. it ran like crap. i assumed it was because the timing was way off and i need to break in the cam. today. i tried to let it idle, but it ran rough and i heard i slight rattling/knocking. when i was putting the timing light on it i noticed that the harmonic balancer was wobbling and almost hitting the power steering pump bracket. i took a closer look and the inner part was perfeclty centered and the outter part was the part wobbling. also it looked like the pully was slightly off to. do you think that the 15 min of 2000-2500 rpm cam break in could have messed up my engine? the timing mark didnt even show up on the balancer with the light on it. what do yall think? and yes, i will getting a new balancer.

Skip Greaney · 02-04-2007, 12:10 AM

If it is a stock balancer it probably has seperated at the rubber absorber. Happens alot from wear strain or a component drag, and alot of people put them on with a block of wood and a hammer instead of using an installer. Get a new one or a aftermarket if the engine is producing over 400 HP!

jbon64 · 02-04-2007, 09:13 AM

if you suspect it shifted you could do the normal #1 piston top dead center , then see if the timing mark is lined up .

cooters · 02-04-2007, 09:27 AM

the balancer wont cause the motor to run like crap, you shouldnt have done bearing damage to the motor in 15 min. Check the key way on the crank to ensure it is good and ALWAYS use a balancer installer

**truckdude239** · 02-04-2007, 10:05 AM

if the breaking period is not done right about 15-20 mins at 2000 rpm you can mess a cam up fast (ie lopes wore off)

crm318 · 02-04-2007, 01:02 PM

yea, i know that the balancer wont cause the motor to run bad. i just saw that the outter part was trashed along with the rubber and i couldnt find that timing mark because of it. im going to get a new balancer. i havent been able to find a cheap one. they go for about 50-60 at the local parts store.

cooters · 02-04-2007, 03:23 PM

50 to 60 for a new balancer is well worth the money. I never use old ones. This problem is why i say you cannot use a timing light on a stock balancer because the marks rarely are in the right place.

02-04-2007, 12:10 AM	#2
Skip Greaney Junior Member Join Date: Jan 2007 Location: Land O' Lakes Florida Posts: 103	Re: wobbly harmonic balancer If it is a stock balancer it probably has seperated at the rubber absorber. Happens alot from wear strain or a component drag, and alot of people put them on with a block of wood and a hammer instead of using an installer. Get a new one or a aftermarket if the engine is producing over 400 HP!

02-04-2007, 09:13 AM	#3
jbon64 Registered User Join Date: Jan 2006 Location: sidney , illinois Posts: 312	Re: wobbly harmonic balancer if you suspect it shifted you could do the normal #1 piston top dead center , then see if the timing mark is lined up . __________________ hey.....smell my finger 64 nova wagon , 63 nova convertible

02-04-2007, 09:27 AM	#4
cooters Senior Member Join Date: Oct 2006 Location: Edmonton Alberta Posts: 458	Re: wobbly harmonic balancer the balancer wont cause the motor to run like crap, you shouldnt have done bearing damage to the motor in 15 min. Check the key way on the crank to ensure it is good and ALWAYS use a balancer installer

02-04-2007, 10:05 AM	#5
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: wobbly harmonic balancer if the breaking period is not done right about 15-20 mins at 2000 rpm you can mess a cam up fast (ie lopes wore off) __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube Last edited by truckdude239; 02-04-2007 at 10:05 AM.

02-04-2007, 01:02 PM	#6
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: wobbly harmonic balancer yea, i know that the balancer wont cause the motor to run bad. i just saw that the outter part was trashed along with the rubber and i couldnt find that timing mark because of it. im going to get a new balancer. i havent been able to find a cheap one. they go for about 50-60 at the local parts store. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

02-04-2007, 12:06 AM	#1
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	wobbly harmonic balancer i currently built a 350 and started it for the first time yesterday. it ran like crap. i assumed it was because the timing was way off and i need to break in the cam. today. i tried to let it idle, but it ran rough and i heard i slight rattling/knocking. when i was putting the timing light on it i noticed that the harmonic balancer was wobbling and almost hitting the power steering pump bracket. i took a closer look and the inner part was perfeclty centered and the outter part was the part wobbling. also it looked like the pully was slightly off to. do you think that the 15 min of 2000-2500 rpm cam break in could have messed up my engine? the timing mark didnt even show up on the balancer with the light on it. what do yall think? and yes, i will getting a new balancer. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

02-04-2007, 03:23 PM	#7
cooters Senior Member Join Date: Oct 2006 Location: Edmonton Alberta Posts: 458	Re: wobbly harmonic balancer 50 to 60 for a new balancer is well worth the money. I never use old ones. This problem is why i say you cannot use a timing light on a stock balancer because the marks rarely are in the right place.



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