BIG vibration and walking all over the road! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

75-K5 · 05-28-2004, 08:53 AM

Got the truck back from the exhaust shop yesterday and timed the engine, so now it runs pretty good (except the vacuum advance diaphragm is busted). Now it's time to concentrate on other things. When I'm going between about 25 and 35, the whole truck shimmies like it's going to pull itself apart. It used to do it even worse, but replacing the carrier bearing helped a little. Could it be the driveshaft out of balance? How much does it normally cost to have a 2 piece shaft overhauled?

When I'm going this speed, I also hear an extremely loud rattling coming from what sounds like right outside the firewall on the drivers side. Its so loud and fast it almost sounds like a ratcheting, much like the noise you hear when you raise a chain hoist.

The truck is also walking all over the road. If I hold the wheel straight, the front tires will spontaneously shift to the right or left a little while I'm driving. It's nothing too scary, it only varies my path by a few feet either way, but it's definitely enough to notice. I have about 1/4 turn of play in the steering wheel, is this the problem or is it alignment? Could it be related to the rattling?

Sorry about all the wacky questions and thanks for any answers!

cdowns · 05-28-2004, 10:06 AM

i would be takin a real good look at your steering and front suspension components sounds like something is on it's way out ,you may also want to take a look at your engine mounts. from the way you've described it it doesn't really sound safe to drive asis cause you might be going down the road and find yourself 3wheelin

**JIMs70GMC** · 05-28-2004, 10:38 AM

Make sure your gear box is bolted tight to the frame. Also check your ball joints. Does the vibration go away above 35? Could be the tires.

Mudder · 05-28-2004, 11:44 AM

Could be a combination of all the things listed. Rivets tend to work loose on the front cross member on those years. Have someone turn the steering wheel back and forth while you lay under there and see if anything is moving when its not supposed to be moving.

MMGOODIE · 05-28-2004, 12:26 PM

I have this same problem except mine is at 60-65 but the smoothes out above 65. My buddy told me to take a look at the ball joints because his did the same thing then he replace the BJ's and the problem went away.

71swb4x4 · 05-28-2004, 01:20 PM

It's nothing too scary, it only varies my path by a few feet either way, but it's definitely enough to notice.

I must be a real wuss cause that sounds pretty scary to me. A few feet either way - I like to know where I am going.

Jeepster376 · 05-28-2004, 01:56 PM

Quote:

Originally Posted by 75-K5

It's nothing too scary, it only varies my path by a few feet either way, but it's definitely enough to notice.

It will get a lot scarier when whatever is loose in your front end lets go. You better thorouly check out that front end and find what's loose. A shimmy at 25-35 is quite serious, as that is a very low speed, something must be quite loose.

75-K5 · 05-28-2004, 03:07 PM

Thanks, I'll take a look at those things. I meant to clarify that the rattle goes away after 35. When I'm going 50, it rides smooth. I was planning on greasing everything up real good, replacing ball joints, and getting it aligned. Hopefully that will help. The engine mounts are brand new.

71swb4x4 · 05-28-2004, 05:10 PM

That sounds exactly like what happened to my friend. He took his truck in to get worked on. When he got it back it drove great for a few days, then had a bad vibration at 20 - 30 mph. Over 30 it was OK so he didn't worry too much.
Then his tire fell off while he was driving.
Turns out they didn't tighten the lugnuts, and when he went fast enough the rotation and weight of the tire kept it from vibrating. So it may not seem serious, but when you are cruising down the highway you may get a surprise

FRENCHBLUE72 · 05-28-2004, 07:56 PM

I would crawl under the truck and check for worn out or lose part's may also be a tire outta ballance??? Inner and outter tir rod's could cause it too..

ckhd · 05-28-2004, 07:56 PM

My '69 K-10 used to do that. I thought it was going to shake itself apart at about 30mph. I knew to accelerate quickly past it, or brake fast through it.

Anyway, it ended up being (mostly) that the front spring bushings were worn out. Allowed it to slop all over. Changed those out, and it almost completely went away. The bearings that hold the axle to the splindle (think kingpins) were messed up too, and that was the rest of the slop.

franko72 · 05-30-2004, 06:17 PM

I can almost bet that your drive shaft is need of balancing. I had a van that did the exact same thing . I got my shaft balanced here in Cincinnati for less than $150.00. That corrected the problem.You should check the U- Joints too

05-28-2004, 08:53 AM	#1
75-K5 Bucket of Bolts Join Date: Dec 2003 Location: Anderson, Indiana Posts: 455	BIG vibration and walking all over the road! Got the truck back from the exhaust shop yesterday and timed the engine, so now it runs pretty good (except the vacuum advance diaphragm is busted). Now it's time to concentrate on other things. When I'm going between about 25 and 35, the whole truck shimmies like it's going to pull itself apart. It used to do it even worse, but replacing the carrier bearing helped a little. Could it be the driveshaft out of balance? How much does it normally cost to have a 2 piece shaft overhauled? When I'm going this speed, I also hear an extremely loud rattling coming from what sounds like right outside the firewall on the drivers side. Its so loud and fast it almost sounds like a ratcheting, much like the noise you hear when you raise a chain hoist. The truck is also walking all over the road. If I hold the wheel straight, the front tires will spontaneously shift to the right or left a little while I'm driving. It's nothing too scary, it only varies my path by a few feet either way, but it's definitely enough to notice. I have about 1/4 turn of play in the steering wheel, is this the problem or is it alignment? Could it be related to the rattling? Sorry about all the wacky questions and thanks for any answers! __________________ This is the project that never ends, yes it goes on and on my friend....

05-28-2004, 10:06 AM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	i would be takin a real good look at your steering and front suspension components sounds like something is on it's way out ,you may also want to take a look at your engine mounts. from the way you've described it it doesn't really sound safe to drive asis cause you might be going down the road and find yourself 3wheelin __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

05-28-2004, 10:38 AM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Make sure your gear box is bolted tight to the frame. Also check your ball joints. Does the vibration go away above 35? Could be the tires. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

05-28-2004, 12:26 PM	#5
MMGOODIE I love doing it topless Join Date: Oct 2003 Location: MossyRock, WA Posts: 493	I have this same problem except mine is at 60-65 but the smoothes out above 65. My buddy told me to take a look at the ball joints because his did the same thing then he replace the BJ's and the problem went away. __________________ Mikey "If you can read this, thank a teacher; If you are reading it in English, thank a soldier."

05-28-2004, 01:20 PM	#6
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	It's nothing too scary, it only varies my path by a few feet either way, but it's definitely enough to notice. I must be a real wuss cause that sounds pretty scary to me. A few feet either way - I like to know where I am going. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

05-28-2004, 11:44 AM	#4
Mudder Registered User Join Date: Feb 2001 Location: East Central, MO Posts: 11,336	Could be a combination of all the things listed. Rivets tend to work loose on the front cross member on those years. Have someone turn the steering wheel back and forth while you lay under there and see if anything is moving when its not supposed to be moving.

05-28-2004, 03:07 PM	#8
75-K5 Bucket of Bolts Join Date: Dec 2003 Location: Anderson, Indiana Posts: 455	Thanks, I'll take a look at those things. I meant to clarify that the rattle goes away after 35. When I'm going 50, it rides smooth. I was planning on greasing everything up real good, replacing ball joints, and getting it aligned. Hopefully that will help. The engine mounts are brand new. __________________ This is the project that never ends, yes it goes on and on my friend....

05-28-2004, 05:10 PM	#9
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	That sounds exactly like what happened to my friend. He took his truck in to get worked on. When he got it back it drove great for a few days, then had a bad vibration at 20 - 30 mph. Over 30 it was OK so he didn't worry too much. Then his tire fell off while he was driving. Turns out they didn't tighten the lugnuts, and when he went fast enough the rotation and weight of the tire kept it from vibrating. So it may not seem serious, but when you are cruising down the highway you may get a surprise __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

05-28-2004, 07:56 PM	#10
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	I would crawl under the truck and check for worn out or lose part's may also be a tire outta ballance??? Inner and outter tir rod's could cause it too.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

05-28-2004, 07:56 PM	#11
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	My '69 K-10 used to do that. I thought it was going to shake itself apart at about 30mph. I knew to accelerate quickly past it, or brake fast through it. Anyway, it ended up being (mostly) that the front spring bushings were worn out. Allowed it to slop all over. Changed those out, and it almost completely went away. The bearings that hold the axle to the splindle (think kingpins) were messed up too, and that was the rest of the slop. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

05-30-2004, 06:17 PM	#12
franko72 Franko72 Join Date: May 2004 Location: Cincinnati,Ohio Posts: 471	I can almost bet that your drive shaft is need of balancing. I had a van that did the exact same thing . I got my shaft balanced here in Cincinnati for less than $150.00. That corrected the problem.You should check the U- Joints too __________________ 1972 C20 cheyenne Super 402 BB/400 turbo LWB A/C Tilt, Cruise Control, Saddle tanks, Tach My Home Page Better to burn out than it is to rust Last edited by franko72; 05-31-2004 at 01:21 AM.



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