Shake or Vibration Issues

[pm26]

 

So how would the PICO scopes analyze this vibration? Would it be in the same harmonics as a tire / wheel?

If the vibration is caused by in an improper pinion shaft to driveshaft angle, the vibration will occur at the actual engine speed in any transmission gear. If the vibrations are caused by wheels, hubs, brake rotors, and/or axles, they typically occur at approximately 1/3 of engine speed (depending on your rear axle ratio). If the vibration frequency remains the same, it is typically a driveline problem, if the vibration frequency changes, the source is typically the engine or transmission.

 

I am not familiar with GM's vibration analyzing methodology, but any GM engineer trained in vibration analysis should be capable of pinpointing the source of vibration with their equipment. The real question remains - are they really trying to find the cause and fix it or merely putting on a show? The main concern will of course be their acceptance/rejection criteria - do we know if these have been adjusted by GM to cover most of the troublesome trucks so they can claim that the trucks perform "within their design parameters." ? These are all questions that remain open at this time.

Edited December 1, 2015 by pm26

[yahtzee]

A while ago I started chasing down editors/writers at top auto rags and publications to try and get some traction on these issues. I also created a Facebook group as an alternative source for information.

 

It finally looks like at least one automobile publication is going to be writing a story about these issues. I just got word that the news editor for a auto rag (can't say just yet) is "finalizing his story on the SUV issues" and asked for more information. I hope this is the bump we need to get GM to get off of their ass and do something. I will keep you all posted. FYI, I have a 2016 Yukon XL Denali with buffeting issues but also with the terrible vibration issues that you guys are experiencing as well.

[14silverado4.3]

A while ago I started chasing down editors/writers at top auto rags and publications to try and get some traction on these issues. I also created a Facebook group as an alternative source for information.

 

It finally looks like at least one automobile publication is going to be writing a story about these issues. I just got word that the news editor for a auto rag (can't say just yet) is "finalizing his story on the SUV issues" and asked for more information. I hope this is the bump we need to get GM to get off of their ass and do something. I will keep you all posted. FYI, I have a 2016 Yukon XL Denali with buffeting issues but also with the terrible vibration issues that you guys are experiencing as well.

Thanks following FB also.... Are they doing vibration and buffeting for both the SUV and the Trucks?

[rshad]

A while ago I started chasing down editors/writers at top auto rags and publications to try and get some traction on these issues. I also created a Facebook group as an alternative source for information.

 

It finally looks like at least one automobile publication is going to be writing a story about these issues. I just got word that the news editor for a auto rag (can't say just yet) is "finalizing his story on the SUV issues" and asked for more information. I hope this is the bump we need to get GM to get off of their ass and do something. I will keep you all posted. FYI, I have a 2016 Yukon XL Denali with buffeting issues but also with the terrible vibration issues that you guys are experiencing as well.

What is your Facebook page on these problems?

[yahtzee]

What is your Facebook page on these problems?

 

https://www.facebook.com/groups/GMissues/

[rshad]

 

https://www.facebook.com/groups/GMissues/

Thanks, Joined the group.

[Luke Fontenot]

If the vibration is caused by in an improper pinion shaft to driveshaft angle, the vibration will occur at the actual engine speed in any transmission gear. If the vibrations are caused by wheels, hubs, brake rotors, and/or axles, they typically occur at approximately 1/3 of engine speed (depending on your rear axle ratio). If the vibration frequency remains the same, it is typically a driveline problem, if the vibration frequency changes, the source is typically the engine or transmission.

 

I am not familiar with GM's vibration analyzing methodology, but any GM engineer trained in vibration analysis should be capable of pinpointing the source of vibration with their equipment. The real question remains - are they really trying to find the cause and fix it or merely putting on a show? The main concern will of course be their acceptance/rejection criteria - do we know if these have been adjusted by GM to cover most of the troublesome trucks so they can claim that the trucks perform "within their design parameters." ? These are all questions that remain open at this time.

 

pinion shaft to driveshaft angle issues will change with vehicle speed/tire speed not engine speed. the drive shaft is always spinning approximately 3 times the speed of the tires.

 

depending what gear the transmission is in will determine the engine speed for a given vehicle speed.

 

you can do 70mph in 5th or 6th. the engine speed will be very different. however the tire rpms and drive shaft rpms will be the same at 70mph in 5th as they are at 70mph in 6th.

Edited December 1, 2015 by Laf7337

[rotaxracing]

has there been any 16's vibrating yet? dealer is taking mine back and ordered a 16 for me. will get it next month.

[LongrangeLauber]

has there been any 16's vibrating yet? dealer is taking mine back and ordered a 16 for me. will get it next month.

As far as we know, no. But, we're pretty sure, not 100%, that nothing has really changed besides the front fascia

 

 

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[rotaxracing]

Thats a little comforting. They must have found something they are not telling us but they are unable(or unwilling) to fix my 14

[C6Bill]

Read back a few pages, I test drove a 2016. That's why I'm driving a Tundra now.

 

And I had a 2016 on order to replace my 2014 too, but GM never picked up the order. Just guessing here but I am sure they knew why it was ordered and that is why it was never picked up.

 

 

And I know I said I was out but I just got a PM from another member of "the club" and I had to come back in to congratulate him on his new RAM.

 

Besides, this is like a train wreck, i just can't stop watching

[4x4 350]

Has anyone tried putting some weight in the bed? I have the 45-55 mph vib and noticed when hauling fire wood it was significantly reduced.

[Smithr66]

The update I have on my truck today is not a good one. The dealer called and said the vibration is "better". They loosened all motor, tranny, exhaust mounts and torqued them all back down. Then the genius field engineer decided to balance my new driveshaft with hose clamps. Is this really the best thing their engineers can come up with?

[C6Bill]

He was out of bubblegum and duct tape lol

[LongrangeLauber]

^^funniest thing I've heard all day [emoji23][emoji23]

 

 

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