Vibration and noise PLEASE - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72chevyLWB · 06-25-2002, 07:28 PM

I am totally confused here. I went on a road trip with my 72. Out on the highway at about 65 it makes a whah whah whah kind of noise (dont laugh) and a vibration comes with the sound. Does it sometimes but not all of the time. If I am really steady with the throttle it won't do it, but if I move the throttle around any it will. I have a 3.73 rear end. I have a 3 series carrier with a ring gear spacer. I checked the pattern on the gears and everything looks good. It has a 1 piece driveshaft that is straight and all u-joints are good. It did that for a while, but all of a sudden one night I have this nasty vibration that shakes everything inside the cab. Anything over 45mph it vibrates no matter what you do, even slowing down. It is also really bad when put in neutral while slowing down (almost gets worse). My wheels are balanced and there are no thrown weights ( I checked). While I had the cover off I re-torqued the ring gear bolts because you have to with the spacer and I got 1/8 to 1/4 turn max out of it so that shouldn't be the problem. I have the original open carrier and might have to throw that in and go from there. Any other help or ideas would be appreciated.

72chevyLWB · 06-25-2002, 07:56 PM

ring gear pattern

72chevyLWB · 06-25-2002, 07:57 PM

spacer

Chevyc10! · 06-25-2002, 08:03 PM

Don't forget to check the motor/ transmission mounts. A broken mount can cause the vibration...
Jake

Wasted Income · 06-25-2002, 08:07 PM

When I rebuilt my 700r4 in my burban, I noticed a nasty vibration that wasn't there before I rebuilt it. It lasted like that for a couple of thousand miles before one day it puked. Boom no forward, no reverse. Park was all I had. Replaced the torque converter, all was well.

Too bad you have a one piece driveshaft, cuz my '69 was doing the exact same thing a couple of summers ago. The carrier bearing had seized up and it twisted off of the mount. The damn thing was just spinning in the crossmember.

Also........if you've replaced u-joints recently, check to see that they are centered in the yoke. I had one about 1/16 off center and it vibrated so badly that it turned the needle bearings in the bearing cap to dust in about 100 miles.

Keep us posted.

-Jeff

Stepside · 06-25-2002, 08:09 PM

Is it the pic, or does some of the teeth look fractured? Might be the gear oil. I dunno. The pattern looks real full on the shiny (non-shadowed) teeth. Almost too full. That lends me to think the pinion depth is shallow. If the shadowed teeth look like this normally, your gears are shot. ¿ A carrier bearing or a axle bearing will give these symptoms.
Stepside

**68 Stepside** · 06-25-2002, 08:16 PM

I'm glad I'm not the only one that noticed the teeth looking a little nasty. Are they chewed up, or is that the pic? The gear itself also appears to have gotten quite hot. Was the fluid low? Did it have an shavings in it?

TJ

72chevyLWB · 06-25-2002, 08:26 PM

The gears are good shape. that is persian blue grease on it to check the pattern. The gears are nice and sharp. Possibly the pinion could come ahead. I have a new converter for it too. I put in the new tranny, posi and flip kit at the same time so I don't know what is causing it. The converter is a non lockup so I need to get it out. Should I do that first? Also when I did the flip kit I got angle shims to get the u-joints straighter. They aren't perfectly straight with the tranny but really close.

72chevyLWB · 06-25-2002, 08:28 PM

here, I wiped it off with a rag quick

Super Chevy · 06-25-2002, 08:38 PM

really dumb question,but sometimes overlooked,did you get your 1pc driveshaft balenced with the new yoke and all?

SC

72chevyLWB · 06-25-2002, 08:44 PM

I have to drive 250 miles to get it balanced up here. I put it on jack stands and ran it up to 60 and quickly crawled under and it looks perfectly straight. It vibated before, but I replaced it and it was fine then because the first one was bowed (don't know how). But why would it not vibrate but make a noise and then all of a sudden vibrate like crazy the next day. I might put the rear end back together and put in the converter first. Keep ideas coming.

Super Chevy · 06-25-2002, 09:34 PM

did it throw a wieght on the driveshaft mabe,if it had wieghts tacked on for balencing

SC

72chevyLWB · 06-25-2002, 09:57 PM

no weights are or were on the shaft before or after the problem.

Super Chevy · 06-25-2002, 10:18 PM

last thing i can think of is mabe your drums are unbalenced,mabe a warp in them or something

Scrub · 06-25-2002, 11:58 PM

I'm with Super CHevy one this one. Check to see if your brake drums are warped, Does pressing the brake have any effect on the vibration? Jack the rear up and spin the tires. Do you hear the brake rub in one spot and not other spot?

Just a thought

Rabid · 06-26-2002, 12:59 AM

Buddy had a similar problem once. Turned out to be packed mud in his wheel hubs. Didn't make the strange noise like you mentioned though. Only things that made that sound on mine was the rear end.

colohusker · 06-26-2002, 01:21 AM

My money is on the converter, since you say it gets worse when thrown into neutral. But just in case, when you had it on the stands and running 60, where were the stands at? Under the axle, or under the frame? Just curious whether the suspension was under load at the time, giving the same angles on the u-joints as when it would be on the road.

Keep us posted! And if all else fails, you could always give the truck to me.

*67Fleetsidedream* · 06-26-2002, 07:23 AM

It sounds to me that it is your drive shaft. Where did you get it?
This is a common problem when the 2 piece shaft is replaced with a 1 piece shaft. Check the slip yoke for excessive play and wobble. The 1 piece shaft out of a later Chevy extended cab is about 1/4 inch shorter than the 2 piece with a Saginaw 3 speed.
So check this. Sounds to be that you have excessive wobble on the slip yoke.

Ben

72chevyLWB · 06-26-2002, 08:15 AM

I had the stands under the axle at the time. There is no play in the driveshaft either. Everything is tight.

*67Fleetsidedream* · 06-26-2002, 08:55 AM

Checked the wheel bearings? How about the front control arm bushings. Does it do it when you turn?
Ben

72chevyLWB · 06-26-2002, 01:27 PM

Its coming from the back. The control arm bushings and such are all new and tight.

**COBALT** · 06-26-2002, 01:50 PM

I'm going to throw a new one in here.

Check your carrier bearings.

Before I had my differential overhauled I had a similar problem. At 45-50 MPH I would start to get this hum from under the truck that got worse the faster I went. The whole cab vibrated. I could feel it in the steering wheel. If I was easy with the acclerator it would go away. If I let off the gas it would go away, but if I gave it any throttle at all it would come back. It started to get progressively worse until it was starting at 35 MPH.

Turns out my carrier bearings were totally pitted. They had flats worn on them they were so bad. Here's the kicker: the ring/pinion were PERFECT. The wear pattern was good, and they can still be slapped into another carrier with no problem (I had them swapped out for 3.90s).

You've checked the gear set. Now check the carrier bearings, pinion bearings (inner/outer), and work your way to the engine checking everything along the way. Since throttle is involved I wouldn't think it had anything to do with the wheel bearings, or brakes unless you feel changes when breaking or when turning corners.

bowtie · 06-26-2002, 02:19 PM

First of all I'm leaning towards the drive shaft being out of balance.

2nd I'm had mud/snow stuck inside the rims and this caused a nasty vibration, clean them out and its fine

3rd I built a stepside and there was a nasty noise and vibration coming from the rear of the pickup and it only happened at certian speeds. It turned out to be the bushing in the rear panhard bar, this would only apply of course if your pickup was a coil spring setup in the rear.

jku72 · 06-26-2002, 05:17 PM

This is a classic example of a driveshaft imbalance, but sometimes the causes and symptoms are harder to pinpoint.
The wah wah wah is usually caused by a harmonic imbalance. My truck does it, but not with your severity, and my problem is a worn rubber cushion in the center bearing housing. That wah wah noise has also been traced to flywheels being loose, or even the tranny bolts loose. The engine and trans are too heavy to detect loosness by moving, so try a couple of the bolts. tighten the converter to flywheel bolts, if you can.

Stepside · 06-26-2002, 05:47 PM

You mentioned using angle shims to get the u-joints straighter. Now I'm thinking your driveline angles are not right. The angle of the pinion should be the same as the angle of the trans output shaft. Not pointing straight to each other.

.............. <trans

...............<pinion

http://www.ring-pinion.com/gear/g1198.shtml

06-25-2002, 07:28 PM	#1
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	Vibration and noise PLEASE I am totally confused here. I went on a road trip with my 72. Out on the highway at about 65 it makes a whah whah whah kind of noise (dont laugh) and a vibration comes with the sound. Does it sometimes but not all of the time. If I am really steady with the throttle it won't do it, but if I move the throttle around any it will. I have a 3.73 rear end. I have a 3 series carrier with a ring gear spacer. I checked the pattern on the gears and everything looks good. It has a 1 piece driveshaft that is straight and all u-joints are good. It did that for a while, but all of a sudden one night I have this nasty vibration that shakes everything inside the cab. Anything over 45mph it vibrates no matter what you do, even slowing down. It is also really bad when put in neutral while slowing down (almost gets worse). My wheels are balanced and there are no thrown weights ( I checked). While I had the cover off I re-torqued the ring gear bolts because you have to with the spacer and I got 1/8 to 1/4 turn max out of it so that shouldn't be the problem. I have the original open carrier and might have to throw that in and go from there. Any other help or ideas would be appreciated. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 07:56 PM	#2
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	ring gear pattern Attached Images __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 07:57 PM	#3
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	spacer Attached Images __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 08:03 PM	#4
Chevyc10! Registered User Join Date: Dec 2000 Location: Centerville Ga. USA Posts: 804	Don't forget to check the motor/ transmission mounts. A broken mount can cause the vibration... Jake __________________ 68 SWB The Surgeon General doesn't say anything about smoking a Ford!!! Would rather be ran over repeatedly by a Chevy than drive a Ford!!! Paralyzed from the neck up and confined to a hat! Kathleen, Georgia USA

06-25-2002, 08:07 PM	#5
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	Torque converter? When I rebuilt my 700r4 in my burban, I noticed a nasty vibration that wasn't there before I rebuilt it. It lasted like that for a couple of thousand miles before one day it puked. Boom no forward, no reverse. Park was all I had. Replaced the torque converter, all was well. Too bad you have a one piece driveshaft, cuz my '69 was doing the exact same thing a couple of summers ago. The carrier bearing had seized up and it twisted off of the mount. The damn thing was just spinning in the crossmember. Also........if you've replaced u-joints recently, check to see that they are centered in the yoke. I had one about 1/16 off center and it vibrated so badly that it turned the needle bearings in the bearing cap to dust in about 100 miles. Keep us posted. -Jeff __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

06-25-2002, 08:09 PM	#6
Stepside Gasser Join Date: May 2000 Location: Thomasville,NC USA Posts: 456	Is it the pic, or does some of the teeth look fractured? Might be the gear oil. I dunno. The pattern looks real full on the shiny (non-shadowed) teeth. Almost too full. That lends me to think the pinion depth is shallow. If the shadowed teeth look like this normally, your gears are shot. ¿ A carrier bearing or a axle bearing will give these symptoms. Stepside __________________ :thud 70 sstep tubbed, Muncie, double hump, snowflake, Last edited by Stepside; 06-25-2002 at 08:12 PM.

06-25-2002, 08:16 PM	#7
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	I'm glad I'm not the only one that noticed the teeth looking a little nasty. Are they chewed up, or is that the pic? The gear itself also appears to have gotten quite hot. Was the fluid low? Did it have an shavings in it? TJ __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

06-25-2002, 08:26 PM	#8
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	The gears are good shape. that is persian blue grease on it to check the pattern. The gears are nice and sharp. Possibly the pinion could come ahead. I have a new converter for it too. I put in the new tranny, posi and flip kit at the same time so I don't know what is causing it. The converter is a non lockup so I need to get it out. Should I do that first? Also when I did the flip kit I got angle shims to get the u-joints straighter. They aren't perfectly straight with the tranny but really close. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 08:28 PM	#9
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	here, I wiped it off with a rag quick Attached Images __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 08:38 PM	#10
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	really dumb question,but sometimes overlooked,did you get your 1pc driveshaft balenced with the new yoke and all? SC

06-25-2002, 08:44 PM	#11
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	I have to drive 250 miles to get it balanced up here. I put it on jack stands and ran it up to 60 and quickly crawled under and it looks perfectly straight. It vibated before, but I replaced it and it was fine then because the first one was bowed (don't know how). But why would it not vibrate but make a noise and then all of a sudden vibrate like crazy the next day. I might put the rear end back together and put in the converter first. Keep ideas coming. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 09:34 PM	#12
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	did it throw a wieght on the driveshaft mabe,if it had wieghts tacked on for balencing SC

06-25-2002, 09:57 PM	#13
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	no weights are or were on the shaft before or after the problem. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-25-2002, 10:18 PM	#14
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	last thing i can think of is mabe your drums are unbalenced,mabe a warp in them or something

06-25-2002, 11:58 PM	#15
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	I'm with Super CHevy one this one. Check to see if your brake drums are warped, Does pressing the brake have any effect on the vibration? Jack the rear up and spin the tires. Do you hear the brake rub in one spot and not other spot? Just a thought __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.



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06-26-2002, 12:59 AM	#16
Rabid Registered User Join Date: May 2001 Location: Honolulu, HI Posts: 1,237	Buddy had a similar problem once. Turned out to be packed mud in his wheel hubs. Didn't make the strange noise like you mentioned though. Only things that made that sound on mine was the rear end.

06-26-2002, 01:21 AM	#17
colohusker Registered User Join Date: Apr 2002 Location: Longmont, CO Posts: 436	My money is on the converter, since you say it gets worse when thrown into neutral. But just in case, when you had it on the stands and running 60, where were the stands at? Under the axle, or under the frame? Just curious whether the suspension was under load at the time, giving the same angles on the u-joints as when it would be on the road. Keep us posted! And if all else fails, you could always give the truck to me. __________________ ------------------------------------------------ I say it's only money, my wife says it's only a truck.... '71 C10 Deluxe, factory ac, ps, pb, should be done by 2102 Longmont, CO husker95@hotmail.com

06-26-2002, 07:23 AM	#18
67Fleetsidedream Wiseass secured himself a BAN Join Date: Nov 2000 Location: MOON!!! Posts: 2,282	It sounds to me that it is your drive shaft. Where did you get it? This is a common problem when the 2 piece shaft is replaced with a 1 piece shaft. Check the slip yoke for excessive play and wobble. The 1 piece shaft out of a later Chevy extended cab is about 1/4 inch shorter than the 2 piece with a Saginaw 3 speed. So check this. Sounds to be that you have excessive wobble on the slip yoke. Ben

06-26-2002, 08:15 AM	#19
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	I had the stands under the axle at the time. There is no play in the driveshaft either. Everything is tight. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-26-2002, 08:55 AM	#20
67Fleetsidedream Wiseass secured himself a BAN Join Date: Nov 2000 Location: MOON!!! Posts: 2,282	Checked the wheel bearings? How about the front control arm bushings. Does it do it when you turn? Ben

06-26-2002, 01:27 PM	#21
72chevyLWB Got 20's???? Join Date: Oct 2001 Location: Aberdeen SD Posts: 1,451	Its coming from the back. The control arm bushings and such are all new and tight. __________________ 99 Silverado Ex-Cab 2wd, Bagged&WhippleCharged 02 Sierra Ex-Cab 4wd 2500 HD The 72 went down the road.

06-26-2002, 01:50 PM	#22
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	I'm going to throw a new one in here. Check your carrier bearings. Before I had my differential overhauled I had a similar problem. At 45-50 MPH I would start to get this hum from under the truck that got worse the faster I went. The whole cab vibrated. I could feel it in the steering wheel. If I was easy with the acclerator it would go away. If I let off the gas it would go away, but if I gave it any throttle at all it would come back. It started to get progressively worse until it was starting at 35 MPH. Turns out my carrier bearings were totally pitted. They had flats worn on them they were so bad. Here's the kicker: the ring/pinion were PERFECT. The wear pattern was good, and they can still be slapped into another carrier with no problem (I had them swapped out for 3.90s). You've checked the gear set. Now check the carrier bearings, pinion bearings (inner/outer), and work your way to the engine checking everything along the way. Since throttle is involved I wouldn't think it had anything to do with the wheel bearings, or brakes unless you feel changes when breaking or when turning corners. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

06-26-2002, 02:19 PM	#23
bowtie Senior Member Join Date: Dec 1999 Location: Saskatchewan Posts: 1,050	First of all I'm leaning towards the drive shaft being out of balance. 2nd I'm had mud/snow stuck inside the rims and this caused a nasty vibration, clean them out and its fine 3rd I built a stepside and there was a nasty noise and vibration coming from the rear of the pickup and it only happened at certian speeds. It turned out to be the bushing in the rear panhard bar, this would only apply of course if your pickup was a coil spring setup in the rear. __________________ ~70 GMCprostreet swb 396/700r NOS 575 hp "the Brick" ~72 chev swb w/68 front clip "GM Millenium corvette yellow" I use and accept Paypal

06-26-2002, 05:17 PM	#24
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	This is a classic example of a driveshaft imbalance, but sometimes the causes and symptoms are harder to pinpoint. The wah wah wah is usually caused by a harmonic imbalance. My truck does it, but not with your severity, and my problem is a worn rubber cushion in the center bearing housing. That wah wah noise has also been traced to flywheels being loose, or even the tranny bolts loose. The engine and trans are too heavy to detect loosness by moving, so try a couple of the bolts. tighten the converter to flywheel bolts, if you can. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

06-26-2002, 05:47 PM	#25
Stepside Gasser Join Date: May 2000 Location: Thomasville,NC USA Posts: 456	You mentioned using angle shims to get the u-joints straighter. Now I'm thinking your driveline angles are not right. The angle of the pinion should be the same as the angle of the trans output shaft. Not pointing straight to each other. .............. <trans ...............<pinion http://www.ring-pinion.com/gear/g1198.shtml __________________ :thud 70 sstep tubbed, Muncie, double hump, snowflake, Last edited by Stepside; 06-26-2002 at 07:00 PM.

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