Shake or Vibration Issues

[Stex]

Haven't had any time to do any of my own diagnosis or get the on car balance, I put in 12 hours each day this weekend on a network move project for a client. Not fun.

 

On my way to work this morning though I noticed a 50mph vibration that I hadn't ever felt before. Not sure if it was a one time deal, if I had just never noticed it before, or if it's a new recurring issue. It was a much slower vibration than the one at 75mph. I'll keep monitoring it. Ugh.

 

I want to keep modding my truck, already have amp steps and a Corsa sport cat back, but I feel like there's no point if I can't get rid of this vibration. I rolled over some negative equity when I got the truck so I'm pretty much stuck in it anyway unless I want a different headache to deal with. If I can't fix the vibration I'll just have to deal with it and won't ever want to finish mods.

 

 

Check with Southwest brake and alignment in San Antonio. They have been truing and balancing my tires on my trucks for years. They can tell you if a tire is to far out to fix or if tread not running true. The balance is great after truing as it is on the truck and balances the entire tire/wheel/rotor. This will eliminate the tire balance question. They drive the truck before and after the work. I have not been there in over a year as once they balance you are good and no rotation of tires required.

 

http://www.southwestbrakeandalignments.com/index.html

Edited October 12, 2016 by STex

[slopra]

I have a similar 50-60 mph vibe in my truck, but it is sporadic. Some days it's there, some days the truck is butter smooth. All my high speed vibes don't exist now after getting these all terrains a while back. But that 50mph vibes feels almost as if it's lugging sort of, kind of lopey if that makes sense. Doesn't bother me enough to worry about it though. I also am continuing the mods on mine lol

 

That sounds exactly what I felt this morning. Lopey makes perfect sense. Certainly not as annoying as the highway vibration, and lowest priority on troubleshooting list.

 

Wheels and tires are on the mod list, maybe I oughta just replace em and hope it fixes the problem as it has for you and others.

 

 

 

 

Check with Southwest brake and alignment in San Antonio. They have been truing and balancing my tires on my trucks for years. They can tell you if a tire is to far out to fix or if tread not running true. The balance is great after truing as it is on the truck and balances the entire tire/wheel/rotor. This will eliminate the tire balance question. They drive the truck before and after the work. I have not been there in over a year as once they balance you are good and no rotation of tires required.

 

http://www.southwestbrakeandalignments.com/index.html

That's the shop I was planning on taking the truck too just gotta find the time during the week to get over there.

Edited October 12, 2016 by slopra

[Stex]

 

 

That sounds exactly what I felt this morning. Lopey makes perfect sense. Certainly not as annoying as the highway vibration, and lowest priority on troubleshooting list.

 

Wheels and tires are on the mod list, maybe I oughta just replace em and hope it fixes the problem as it has for you and others.

 

 

That's the shop I was planning on taking the truck too just gotta find the time during the week to get over there.

 

 

You can drop it or wait for it. IF waiting, get there real early as they start lining up by 7 am and techs do not start tell 8. "Sometimes" they free up in the afternoon. You can call around 1pm to check and drop by about 2-3pm and get right in to the balancing techs. They need a good 1 1/2 to 2 hours.

 

If you add big knobby tires this service is a must. I run Michelins LTX M/S and let them true them after 500-1000 miles put on the new tires.

Edited October 12, 2016 by STex

[Willyone]

Same here. There area few minor mods I'd like to do to my '16 Z71 but with the vibration issue, I don't wanna dump any $$ into it until, or if, the issue is resolved.

 

Hell I didn't need to spend $44K on a fk'n vibrator when I could'a had one for $9.95 from Adam & Eve LOL.

Edited October 12, 2016 by Willyone

[07Softail]

Great news for me on resolving the shaking on my 14 RCSB. As I was building my 6l80 with performance mods I took my driveshaft to a really good drive line shop that does BIG HP race cars and Semi Truck driveshafts. They chucked it in there machine and it was 0.065 of an inch off plane which is a little over 1/16th of an inch. They trued it and checked balance and it is spot on so my particular shaking issue is 100% gone!

 

Glen also told me that they have trued and or built alot of NEW Dodge truck shafts with the same issue and they also use AAM driveshafts and that's exactly what GM uses. So apparently AAM's runout tolerance sucks and should be tighten up a bit. He actually pointed at the decal that AAM puts on the driveshaft and said thats your problem! So guys and gals take your truck to a Drivetrain specialist and have them check runout on the driveshaft. I tested it on a smooth as glass patch of Interstate with a bottle of water and it never shook or moved a bit other than a bump in the road and it drives sooooo much better and it's very relieving to get this resolved. Any questions just ask! Oh and it only cost me $86.00

 

RT

[Harmholland]

So GM is selling a lot of these trucks. How many of them are shaking? Is that 5%,10%, 20% or even more??

[LongrangeLauber]

So GM is selling a lot of these trucks. How many of them are shaking? Is that 5%,10%, 20% or even more??

No one really knows

[Willyone]

Great news for me on resolving the shaking on my 14 RCSB. As I was building my 6l80 with performance mods I took my driveshaft to a really good drive line shop that does BIG HP race cars and Semi Truck driveshafts. They chucked it in there machine and it was 0.065 of an inch off plane which is a little over 1/16th of an inch. They trued it and checked balance and it is spot on so my particular shaking issue is 100% gone!

 

Glen also told me that they have trued and or built alot of NEW Dodge truck shafts with the same issue and they also use AAM driveshafts and that's exactly what GM uses. So apparently AAM's runout tolerance sucks and should be tighten up a bit. He actually pointed at the decal that AAM puts on the driveshaft and said thats your problem! So guys and gals take your truck to a Drivetrain specialist and have them check runout on the driveshaft. I tested it on a smooth as glass patch of Interstate with a bottle of water and it never shook or moved a bit other than a bump in the road and it drives sooooo much better and it's very relieving to get this resolved. Any questions just ask! Oh and it only cost me $86.00

 

RT

 

Huge congrats 07Softail....from a '12 Road King guy LOL.

 

I took mine down the highway yesterday morning and little to no vibration. Weird...got up to around 85 mph and nuth'n. I have no idea why as the vibe is always there from about 74 mph and up. It was about 52 degrees outside so maybe due to cooler temps?? What a bunch'a bullshidt.

[lee16silverado]

Great news for me on resolving the shaking on my 14 RCSB. As I was building my 6l80 with performance mods I took my driveshaft to a really good drive line shop that does BIG HP race cars and Semi Truck driveshafts. They chucked it in there machine and it was 0.065 of an inch off plane which is a little over 1/16th of an inch. They trued it and checked balance and it is spot on so my particular shaking issue is 100% gone!

 

Glen also told me that they have trued and or built alot of NEW Dodge truck shafts with the same issue and they also use AAM driveshafts and that's exactly what GM uses. So apparently AAM's runout tolerance sucks and should be tighten up a bit. He actually pointed at the decal that AAM puts on the driveshaft and said thats your problem! So guys and gals take your truck to a Drivetrain specialist and have them check runout on the driveshaft. I tested it on a smooth as glass patch of Interstate with a bottle of water and it never shook or moved a bit other than a bump in the road and it drives sooooo much better and it's very relieving to get this resolved. Any questions just ask! Oh and it only cost me $86.00

 

RT

Did you also replace the torque converter when you had the driveshaft rebalance?

[mookdoc6]

Great News.......Others have done this to no avail though? They can be out of tolerance quite a bit with meaningless outcomes? GM has the necessary means, brains to look into this and they have not claimed it to be Drive shaft. Makes you wonder if 4-5 are in play?

Edited October 13, 2016 by mookdoc6

[Willyone]

Great News.......Others have done this to no avail though? They can be out of tolerance quite a bit with meaningless outcomes? GM has the necessary means, brains to look into this and they have not claimed it to be Drive shaft. Makes you wonder if 4-5 are in play?

 

I mentioned before, either in this thread or another "shake" thread, I believe that by now GM would have to know what the problem is, or problems are, that cause the vibrations in these trucks. I'm thinking corrections to the vibes is either expensive, involved, or a combo of both. And GM is just dancing around the issues hoping they can avoid having to fork out the $$ for the repairs. Could I be wrong?? Sure, but ....

[slopra]

 

Huge congrats 07Softail....from a '12 Road King guy LOL.

 

I took mine down the highway yesterday morning and little to no vibration. Weird...got up to around 85 mph and nuth'n. I have no idea why as the vibe is always there from about 74 mph and up. It was about 52 degrees outside so maybe due to cooler temps?? What a bunch'a bullshidt.

 

So I've been thinking about this a lot; what could be causing an intermittent vibration, or one that just varies in intensity. I'm getting the same thing, although it has only ever rode completely smooth once. I can't find a correlation between an environmental factor and the vibration intensity.. unless you consider having to gun it from a stop on an extremely bumpy road to get across traffic an environmental factor. After that I was immediately getting on the highway and when I got up to speed, the vibrations were so bad I thought my truck was going to fall apart. After about 10 minutes it finally mellowed out to "normal" vibrations. That time was the only time I've been able to attribute anything specific to a change in vibration.

 

Anyways, back to the basic thought of what could cause a varying vibration:

• Out of round, or not, tires slipping on an out of round, or not, wheel. Obviously at least one of the two must be out of round to produce the 1st order vibration, and only as the high spot slips around wheel/tire.
• The "wheel hop frequency" AKA resonant frequency of the suspension changing. There's a few things to consider with this one:
  • Wheel hop frequency is unavoidable. It's simply the natural resonant frequency of the suspension, it's not the root cause of the vibration itself. This resonant frequency changes depending on the spring constant and/or the weight of the vehicle. This could potentially explain why owners have noticed differences with full tanks vs empty ones, and loaded beds vs unloaded.
  • It is (most of the time) a first harmonic of radial force that oscillates at the same frequency of the natural resonant frequency of the suspension (which is forever changing) that causes the vibration to occur
  • So knowing this, we've opened ourselves back up to all of the other potential components that could cause a 1st order vibration that I went over in my last big post. Since the wheel hop frequency is always changing, anything producing a 1st order vibration might only cause a vibration as the wheel hop frequency changes to a matching frequency and could produce a varying intensity depending on the level of correlation.
  • This could mean that even if every component of the wheel assembly was "perfectly" round (within tolerance) and the entire wheel assembly alone did not produce any noticeable vibration through to the cab, the frequency that it does produce could set off the resonant frequency of the suspension. This could be the vibration that we feel.
  • So again, we're back to an on car balance or a dynamic balancer (Centramatics or BalanceMasters) being a promising fix in theory. They both reduce 1st order vibrations of all components at the same time dynamically.
  • I'm also thinking that an add-a-leaf kit might be a simple way of changing the natural resonance of the suspension enough across its entire range that it wouldn't react to a 1st harmonic radial force from the wheel assembly at highway speeds. I don't know if that would cause it to react at a higher or lower speed though. Relatively cheap thing to try. Has anyone happened to do this already?

Also, just another thing to think about; just like the wheel assembly, the driveshaft and all of it's related components can be out of round and/or out of balance. So just like balancing a tire can't fix a hub or rotor issue, balancing a driveshaft can't fix other components that might have an issue. That being said, there is also the same two solutions as the wheel assembly if replacing parts doesn't fix the issue. On car driveshaft balancing is a thing, although I think there's even less shops that do that then on car wheel balancing. And BalanceMasters also makes a dynamic driveshaft balancer using the same technology as their dynamic wheel balancers.

 

Let's keep those brain juices flowing and figure out these vibration issues, at the end of the day there is a logical and scientific explanation, we just have to find it! The ideas I bring up may sound far fetched and are historically rare, but the logic is valid. I almost never speak off the top of my head in these posts and verify it all on the spot as I'm writing. Also, I think we're well past sticking with orthodox solutions/troubleshooting!

[07Softail]

Did you also replace the torque converter when you had the driveshaft rebalance?

I did install a Circle D

 

RT

[07Softail]

 

So I've been thinking about this a lot; what could be causing an intermittent vibration, or one that just varies in intensity. I'm getting the same thing, although it has only ever rode completely smooth once. I can't find a correlation between an environmental factor and the vibration intensity.. unless you consider having to gun it from a stop on an extremely bumpy road to get across traffic an environmental factor. After that I was immediately getting on the highway and when I got up to speed, the vibrations were so bad I thought my truck was going to fall apart. After about 10 minutes it finally mellowed out to "normal" vibrations. That time was the only time I've been able to attribute anything specific to a change in vibration.

 

Anyways, back to the basic thought of what could cause a varying vibration:

• Out of round, or not, tires slipping on an out of round, or not, wheel. Obviously at least one of the two must be out of round to produce the 1st order vibration, and only as the high spot slips around wheel/tire.
• The "wheel hop frequency" AKA resonant frequency of the suspension changing. There's a few things to consider with this one:
  • Wheel hop frequency is unavoidable. It's simply the natural resonant frequency of the suspension, it's not the root cause of the vibration itself. This resonant frequency changes depending on the spring constant and/or the weight of the vehicle. This could potentially explain why owners have noticed differences with full tanks vs empty ones, and loaded beds vs unloaded.
  • It is (most of the time) a first harmonic of radial force that oscillates at the same frequency of the natural resonant frequency of the suspension (which is forever changing) that causes the vibration to occur
  • So knowing this, we've opened ourselves back up to all of the other potential components that could cause a 1st order vibration that I went over in my last big post. Since the wheel hop frequency is always changing, anything producing a 1st order vibration might only cause a vibration as the wheel hop frequency changes to a matching frequency and could produce a varying intensity depending on the level of correlation.
  • This could mean that even if every component of the wheel assembly was "perfectly" round (within tolerance) and the entire wheel assembly alone did not produce any noticeable vibration through to the cab, the frequency that it does produce could set off the resonant frequency of the suspension. This could be the vibration that we feel.
  • So again, we're back to an on car balance or a dynamic balancer (Centramatics or BalanceMasters) being a promising fix in theory. They both reduce 1st order vibrations of all components at the same time dynamically.
  • I'm also thinking that an add-a-leaf kit might be a simple way of changing the natural resonance of the suspension enough across its entire range that it wouldn't react to a 1st harmonic radial force from the wheel assembly at highway speeds. I don't know if that would cause it to react at a higher or lower speed though. Relatively cheap thing to try. Has anyone happened to do this already?

Also, just another thing to think about; just like the wheel assembly, the driveshaft and all of it's related components can be out of round and/or out of balance. So just like balancing a tire can't fix a hub or rotor issue, balancing a driveshaft can't fix other components that might have an issue. That being said, there is also the same two solutions as the wheel assembly if replacing parts doesn't fix the issue. On car driveshaft balancing is a thing, although I think there's even less shops that do that then on car wheel balancing. And BalanceMasters also makes a dynamic driveshaft balancer using the same technology as their dynamic wheel balancers.

 

Let's keep those brain juices flowing and figure out these vibration issues, at the end of the day there is a logical and scientific explanation, we just have to find it! The ideas I bring up may sound far fetched and are historically rare, but the logic is valid. I almost never speak off the top of my head in these posts and verify it all on the spot as I'm writing. Also, I think we're well past sticking with orthodox solutions/troubleshooting!

My truck didn't vibrate like the pinion angle was off it shook like King Kong had ahold of it shacking the shit out of it. 100% fixed nothing nadda zilch!

 

RT

[Willyone]

slopra said... "Let's keep those brain juices flowing and figure out these vibration issues, at the end of the day there is a logical and scientific explanation, we just have to find it! The ideas I bring up may sound far fetched and are historically rare, but the logic is valid. I almost never speak off the top of my head in these posts and verify it all on the spot as I'm writing. Also, I think we're well past sticking with orthodox solutions/troubleshooting!​"

 

​I agree with you. I'm not an engineer or mechanic, but am somewhat mechanically inclined, and do generally understand the physical aspects of things, and generally understand something once it is explained to me. That said, and this is just is totally a shot in the dark, for some members here tire and or wheel replacement has worked. For some, such as 07softail drive shaft balancing has worked. But for many if not most who have had the tires/wheels and or driveshaft balanced or replaced, the vibe is still there. Couple of weeks ago the dealer man told me he test drove the truck and felt the vibration. Said he/they checked the tire balance, suspension, steering, drive train, and all was ok. Well, it is not ok. 10/11 when I drove the truck there was little to no vibes at all. Truck was not driven yesterday 10/12. I drove truck today to an appointment and after leaving the driveway I got a real and very noticeable vibe at 45 mph...worst ever in fact. 4 miles to the highway and at 74 mph the vibration started and stayed up to 85ish mph. So, the vibe has been present every time I've driven the truck, except for one time 11/11....weird.

 

Guys here have replaced hubs, rotors, cv's, driveshafts, rear end parts, fk'ed with springs and the u-bolts, exhaust, and unfortuneatly I don't recall reading a whole lot'a success stories, although I have read a few. I think about the only things that guys here have not yet replaced are transmissions and tq converters. And I'm wondering if one of those, or both, might be the main issue. As I mentioned in a previous post, I'm guessing GM knows what the main problem/s is, or are, and they're avoiding addressing it. Just a crazy thought....