Vibration at 40

marman · March 17, 2005

My Silverado has a vibration between 39 and 43 MPH. I have had the driveline balanced, new u joints, carrier bearing and the tires rotated and balalance twice. I would describe the vibration as a rumble. You can feel it in your ears and you can hear the door panels rattle when it is cold outside. Probably not a good situation. The truck is smooth when accelerting up to 39, and smooth from 44 on up. It's rough when slowing down through that range. Something seeems to be out of balance, but what? Any ideas? Thanks.

71GMC_3/4T · March 17, 2005

Does it do it in all gears?

If you coast down thru that speed in neutral, does it vibrate?

GM-Tech · March 17, 2005

I assume this is the 1999 in your signature line? This is something that has recently developed or been there since day one? Is it only this way when slowing down through that range or is it there when accelerating through it too. If you pop it in neutral at 55 mph and shut off the engine and let it coast down through that 43-39 range, is it still there?

I don't really have anything specific for you. Sounds like you've covered the most common items. Sounds like the right speed for a driveline problem rather than tires/wheels. But without knowing the frequency, it's hard to say for sure. Anything not stock? Huge tires, jacked up, etc.

BTW, The feeling in the ears is called a "boom".

71GMC_3/4T · March 17, 2005

Hey, GM-Tech, I think you're on to it maybe. My CrewCab "Booms" when one back window is down a little at certain speeds. (I never knew it was called that, thanks!) Drives people nuts sometimes... Real bad in my buddy's '99 Yukon.

Maybe he should check his vents in the doors, or wherever else they may be?

GM-Tech · March 17, 2005

Hey, GM-Tech, I think you're on to it maybe. My CrewCab "Booms" when one back window is down a little at certain speeds.

Yeah, quite a few vehicles have a real nasty boom when just a rear window is down. Lowering just a rear window in a Trailblazer will just about drive you out of the vehicle, it's so bad.

But booms are not just caused by open windows. Driveline can cause this. Astro's were good for this and we had a replacement companion flange that had this huge weight on it to help elminate this noise. They also added dampers to the rear leaf springs that helped quite a bit. On the S-10 Blazer, that had a bad boom that came from the roof panel. Throwing a spare tire up on the roof would eliminate it. But nothing else would and we bought back more than one under the lemon law because of it. It was actually transmitting up through the body mounts into the body and the roof would amplify it into the boom one felt/heard.

Lots of causes. They're not always easy to find.

marman · March 18, 2005

Now I know how to describe my vibration - Boom! Thanks.

To answer some of the questions. It started at about 45,000. Truck now has 60,000. Truck is the 1999 in my sig. it is a long bed. All stock. Vibration occurrs accelerating, deaccelerting, in drive, third, second and nuetral (I haven't noticed it in first, but the engine would be rapped up pretty high at those speeds and I wouldn't be able to tell.)

Thanks all for your interest. Now if we can only pin it down... I love my truck, had it since new.

71GMC_3/4T · March 18, 2005

Does it change w/ 4x4 on or off?

I won't ask you if it does it in reverse...

Find the vents in your doors and possibly in the back of the cab. Tape over them with masking tape and see if there's a change.

If it's drumming your ears, that's usually an indication that some body panel is floppin' or you have a big air leak somewhere.

I bought my truck in Arvada, by the way. I also used to live there.

Your truck isn't doing this on I-70 between I-25 and Sheridan where it's rougher than heck is it? My dog upchucked on my buddy's leg along that stretch it was so bumpy. My buddy was alright for about 15 seconds, then he pulled over and covered a nice section of pavement himself!

marman · March 18, 2005

Does it change w/ 4x4 on or off?
I won't ask you if it does it in reverse...

Find the vents in your doors and possibly in the back of the cab. Tape over them with masking tape and see if there's a change.

If it's drumming your ears, that's usually an indication that some body panel is floppin' or you have a big air leak somewhere.

I bought my truck in Arvada, by the way. I also used to live there.

Your truck isn't doing this on I-70 between I-25 and Sheridan where it's rougher than heck is it? My dog upchucked on my buddy's leg along that stretch it was so bumpy. My buddy was alright for about 15 seconds, then he pulled over and covered a nice section of pavement himself!

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What a hoot. Actually, it does do it on that stretch of road as it is so over full of traffic in the morning it is often moving along at my 'favorite' speed 39-43 mph! I haven't taken up to that speed in 4 wheel drive, I'm a bit paranoid about going that fast in 4X4 and our roads have been very dry of late. I was thinking of taking off the front drive shaft and going for a drive to see if that makes any difference. The feeling in my ears is more akin to hearing low-frequency distortion, kind of like you would hear from a sub-woofer, but I can feel the truck shake at the 39-43 mph range. Thanks.

NDH 66 · March 26, 2005

My Silverado has a vibration between 39 and 43 MPH. I have had the driveline balanced, new u joints, carrier bearing and the tires rotated and balalance twice. I would describe the vibration as a rumble. You can feel it in your ears and you can hear the door panels rattle when it is cold outside. Probably not a good situation. The truck is smooth when accelerting up to 39, and smooth from 44 on up. It's rough when slowing down through that range. Something seeems to be out of balance, but what? Any ideas? Thanks.

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NDH 66 · March 26, 2005

I had the same problem on a 89 , Chev dealer tried everything. Problem went away when I replaced the tires, never happened again still have the truck.

marman · March 31, 2005

I had the same problem on a 89 , Chev dealer tried everything. Problem went away when I replaced the tires, never happened again still have the truck.

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This vibration started about 5,000 miles after I had new Michelin LT tiires put on it. Took it back for rebalance, and no change.

I put about 180lbs of sand in the back the other day, and the vibration is almost gone. I guess my truck got tweaked some how and this vibration is something I'll have to live with. Thanks for the advise.

NDH 66 · March 31, 2005

I had the same problem on a 89 , Chev dealer tried everything. Problem went away when I replaced the tires, never happened again still have the truck.

<{POST_SNAPBACK}>

This vibration started about 5,000 miles after I had new Michelin LT tiires put on it. Took it back for rebalance, and no change.

I put about 180lbs of sand in the back the other day, and the vibration is almost gone. I guess my truck got tweaked some how and this vibration is something I'll have to live with. Thanks for the advise.

<{POST_SNAPBACK}>

NDH 66 · March 31, 2005

I had the same problem on a 89 , Chev dealer tried everything. Problem went away when I replaced the tires, never happened again still have the truck.

<{POST_SNAPBACK}>

This vibration started about 5,000 miles after I had new Michelin LT tiires put on it. Took it back for rebalance, and no change.

I put about 180lbs of sand in the back the other day, and the vibration is almost gone. I guess my truck got tweaked some how and this vibration is something I'll have to live with. Thanks for the advise.

<{POST_SNAPBACK}>

NDH 66 · March 31, 2005

I had the same problem on a 89 , Chev dealer tried everything. Problem went away when I replaced the tires, never happened again still have the truck.

<{POST_SNAPBACK}>

This vibration started about 5,000 miles after I had new Michelin LT tiires put on it. Took it back for rebalance, and no change.

I put about 180lbs of sand in the back the other day, and the vibration is almost gone. I guess my truck got tweaked some how and this vibration is something I'll have to live with. Thanks for the advise.

<{POST_SNAPBACK}>

Hope I'm in the right place here, I' m new .

What I would try, with no costs just a little time. Take 1 tire off at a time and put your spare on and see if it changes anything. That way you would eliminate a bent wheel or a tire problem