Weird and Loud vibration please help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

allen123 · 11-09-2008, 07:38 PM

Ok my truck has a really loud and annoying vibration when i get my truck at about 2500 rpms and stops at 4000 rpms. Its not my tire balance or alignment cause it does it when it's in park revving it up. I replaced my rear U-joint but not my front so it might be that or Someone said it could be my flywheel.
Anybody else having this?

roughedup72 · 11-09-2008, 07:42 PM

Flywheel, bent fan blade, or harmonic balancer

1968SWBBigBlock · 11-09-2008, 07:43 PM

2nd all the above

69trk · 11-09-2008, 07:45 PM

if you're stopped and it's doing it, it's not the ujoints. If its a flywheel it will sound like a rod knocking. Could be a harmonic balancer.

allen123 · 11-09-2008, 07:50 PM

alright thanks
I already replaced the harmonic balancer
It could be the fan blade cause its pretty roughed up
But im not sure if it would make that big of a vibration cause its a pretty rough vibration
And its been doing it since i got the truck and my flywheel just started clicking like that yesterday

Longhorn Man · 11-09-2008, 07:57 PM

what engine does it have?

allen123 · 11-09-2008, 08:02 PM

350/350

pugs · 11-09-2008, 11:12 PM

check the flywheel for cracks and convertor bolts

allen123 · 11-09-2008, 11:28 PM

Ok thanks
Well took the fan off earlier to see if it was it and its not the fan, So i guess it leaves it to the flywheel my dad is going to be home tomorrow so we'll prob take it off and look at it.

acl · 11-11-2008, 09:37 AM

did this just start? Did it start after changing anything? I had the same problem and did all the same things you did. It was the flywheel. Is it a 400 flywheel? Have you lowered or altered stance and changed pinion angle? Again the big ? is when did it start. Gary

acl · 11-11-2008, 09:40 AM

does it shudder at any speed. I bet it is the flywheel, cracked or not a 350 flywheel

**truckdude239** · 11-11-2008, 10:35 AM

Quote:

Originally Posted by allen123

. Its not my tire balance or alignment cause it does it when it's in park revving it up.
Anybody else having this?

that right there tells you it is not a u joint because in park your drive shaft is not spinning

kcjones · 11-11-2008, 12:01 PM

I third (or fourth?) the flexplate. They crack, they warp in high temps, the bolts take a huge beating every day. If it's at particular rpm, it's likely not crank/rod/pistons. So you only have balancer/pulleys/fan/flexplate left...

allen123 · 11-11-2008, 12:10 PM

Quote:

Originally Posted by acl

did this just start? Did it start after changing anything? I had the same problem and did all the same things you did. It was the flywheel. Is it a 400 flywheel? Have you lowered or altered stance and changed pinion angle? Again the big ? is when did it start. Gary

It's been doing it since i got the truck in april.

11-09-2008, 07:38 PM	#1
allen123 It'll buff out Join Date: Mar 2008 Location: Blanchard,Ok Posts: 1,376	Weird and Loud vibration please help Ok my truck has a really loud and annoying vibration when i get my truck at about 2500 rpms and stops at 4000 rpms. Its not my tire balance or alignment cause it does it when it's in park revving it up. I replaced my rear U-joint but not my front so it might be that or Someone said it could be my flywheel. Anybody else having this? __________________ 1972 Chevy c10 swb 2008 CBR600RR Grafitti edition My Build Cody Allen Last edited by allen123; 11-09-2008 at 07:39 PM.

11-09-2008, 07:42 PM	#2
roughedup72 Senior Member Join Date: Oct 2005 Location: south carolina Posts: 658	Re: Weird and Loud vibration please help Flywheel, bent fan blade, or harmonic balancer __________________ 1972 chevy cheyenne 10,nothing special at the moment,Its a work in progress, Working on the engine, paint and body,engine, paint and body,now its the suspenion, ahh hell I'm about tired of working on it. Maybe it will be a rat rod.

11-09-2008, 07:43 PM	#3
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Weird and Loud vibration please help 2nd all the above __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

11-09-2008, 07:45 PM	#4
69trk Registered User Join Date: Oct 2006 Location: bridgecreek ok. Posts: 1,214	Re: Weird and Loud vibration please help if you're stopped and it's doing it, it's not the ujoints. If its a flywheel it will sound like a rod knocking. Could be a harmonic balancer.

11-09-2008, 07:50 PM	#5
allen123 It'll buff out Join Date: Mar 2008 Location: Blanchard,Ok Posts: 1,376	Re: Weird and Loud vibration please help alright thanks I already replaced the harmonic balancer It could be the fan blade cause its pretty roughed up But im not sure if it would make that big of a vibration cause its a pretty rough vibration And its been doing it since i got the truck and my flywheel just started clicking like that yesterday __________________ 1972 Chevy c10 swb 2008 CBR600RR Grafitti edition My Build Cody Allen

11-09-2008, 07:57 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Weird and Loud vibration please help what engine does it have?

11-09-2008, 08:02 PM	#7
allen123 It'll buff out Join Date: Mar 2008 Location: Blanchard,Ok Posts: 1,376	Re: Weird and Loud vibration please help 350/350 __________________ 1972 Chevy c10 swb 2008 CBR600RR Grafitti edition My Build Cody Allen

11-09-2008, 11:12 PM	#8
pugs Registered User Join Date: Mar 2003 Location: Hamburg Pa Posts: 1,153	Re: Weird and Loud vibration please help check the flywheel for cracks and convertor bolts __________________ I don't do thing cuz I can, I do it cuz someone told me it couldn't be done...

11-09-2008, 11:28 PM	#9
allen123 It'll buff out Join Date: Mar 2008 Location: Blanchard,Ok Posts: 1,376	Re: Weird and Loud vibration please help Ok thanks Well took the fan off earlier to see if it was it and its not the fan, So i guess it leaves it to the flywheel my dad is going to be home tomorrow so we'll prob take it off and look at it. __________________ 1972 Chevy c10 swb 2008 CBR600RR Grafitti edition My Build Cody Allen

11-11-2008, 09:37 AM	#10
acl Registered User Join Date: May 2007 Location: Emporia, kansas Posts: 300	Re: Weird and Loud vibration please help did this just start? Did it start after changing anything? I had the same problem and did all the same things you did. It was the flywheel. Is it a 400 flywheel? Have you lowered or altered stance and changed pinion angle? Again the big ? is when did it start. Gary

11-11-2008, 09:40 AM	#11
acl Registered User Join Date: May 2007 Location: Emporia, kansas Posts: 300	Re: Weird and Loud vibration please help does it shudder at any speed. I bet it is the flywheel, cracked or not a 350 flywheel

11-11-2008, 12:01 PM	#13
kcjones I wish I was a cowboy Join Date: Apr 2008 Location: Rohnert Park, CA Posts: 409	Re: Weird and Loud vibration please help I third (or fourth?) the flexplate. They crack, they warp in high temps, the bolts take a huge beating every day. If it's at particular rpm, it's likely not crank/rod/pistons. So you only have balancer/pulleys/fan/flexplate left... __________________ -Kris Met list: Cyclone,Wilson,TranzAm,extd56,hotrodhomi,mnky30,Rokcrln,Brad,JerryJones(well, his truck anyway).



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