Shake or Vibration Issues

14silverado4.3 · January 4, 2017

Can someone repost the video of the runout? i found them

Edited January 4, 2017 by 14silverado4.3

07Softail · January 4, 2017

So, it sounds like machining the axle flanges has worked for several people? Correct, problem goes away completely?

If so, has anyone sent Mary Barra the news? If it works, then GM would finally have a solution and we can all stop dicking around with it

I sent and email and videos to AAM which is who Manufactures the Axle assemblies and drive shafts for these trucks. No response and no surprise! Mine feels perfect but my OCD is making me wanna check to OD of the ring gear as a few have had gears replaced and it seemed to fix their particular issue.... I will do so when weather clears up

RT

Darth_Vader · January 4, 2017

2 degree's

RT

Okay, I'm running 3 right now but think I'll keep it as is until I get the rest done. Were the Yukon axles a direct swap or did you need new shaft bearings? Thinking I'm going to replace them regardless at this point as it's the last OE piece on my trucks rear drive.

abominable z71 · January 4, 2017

I sent and email and videos to AAM which is who Manufactures the Axle assemblies and drive shafts for these trucks. No response and no surprise! Mine feels perfect but my OCD is making me wanna check to OD of the ring gear as a few have had gears replaced and it seemed to fix their particular issue.... I will do so when weather clears up

RT

RT,

Does it appear the outer portion of the hub flange is never turned after being forged, like they figure it's "round enough"?

07Softail · January 4, 2017

Okay, I'm running 3 right now but think I'll keep it as is until I get the rest done. Were the Yukon axles a direct swap or did you need new shaft bearings? Thinking I'm going to replace them regardless at this point as it's the last OE piece on my trucks rear drive.

MRW412 replaced his stock axles with yukon axles not me, I think my post might have looked like i did. They are a direct swap though. I turned mine down on my lathe and got em trued up nice.

RT

RT,

Does it appear the outer portion of the hub flange is never turned after being forged, like they figure it's "round enough"?

It looked pretty crude as far as machining goes but yes the very outer edge was raw forged on one side.

RT

07Softail · January 4, 2017

Do this guys.... get a visual point of reference for me was the top of the e-brake shoe and watch the video in super slow .25 speed and you can see how out of round it is and actually has a couple of dips in it. CRAZY CRAZY!

RT

Pinnacle · January 5, 2017

Funny, cause tires solved my issue 95% of the way...

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Ive seen several guys on other GM forums say its fixed 90 95%, what does that mean? It has to be 100% Its gone or its not.

Its hard to figure this out because it happens from 100 to 30k+ miles on various vehicles. If it was something like a axle flanges it should happen from the first few miles, but it doesn't. So damn frustrating.

Wrench589 · January 5, 2017

Ive seen several guys on other GM forums say its fixed 90 95%, what does that mean? It has to be 100% Its gone or its not.

Its hard to figure this out because it happens from 100 to 30k+ miles on various vehicles. If it was something like a axle flanges it should happen from the first few miles, but it doesn't. So damn frustrating.

You make a good point. If it is the axle flange TIR, it would be present immediately, and always there. It would go away for a while, then come back.

Moreover, it would be present at all speeds, just at a different amplitude - the faster the speed, the greater the amplitude. In fact, the amplitude would go upswing the square of the rpm. I can't come up with a scenario that any mechanical "defect" would come and go as most people have observed, other than the coupling effects between the right and left side of the vehicle. When the unbalance is in phase, it adds t each other. When out if phase, they cancel. And the right and left side wheel/ties will change phasing as you go around corners. Still, enough to account for the observations? Hard to say.

I think the more plausible situation is that there is an inherent natural frequency in the vehicle that is excited by many things - out of balance driveshafts, out f balance wheels/tires, excessive road force in the tires, even unbalance in the axles. You can't get rid of all those possible excitation forces completely, as it's not feasible to perfectly balance something. But if they are low enough, the natural frequency is not excited. Until the tires wear a bit.

Of course, pure conjecture on my part!

C6Bill · January 6, 2017

I think the more plausible situation is that there is an inherent natural frequency in the vehicle that is excited by many things - out of balance driveshafts, out f balance wheels/tires, excessive road force in the tires, even unbalance in the axles. You can't get rid of all those possible excitation forces completely, as it's not feasible to perfectly balance something. But if they are low enough, the natural frequency is not excited. Until the tires wear a bit.

Of course, pure conjecture on my part!

Well said.

And it is all transferred to the driver through that wonderfully stiff frame.

Snoringbear · January 6, 2017

Well said.

And it is all transferred to the driver through that wonderfully stiff frame.

An excellent hypothesis by Wrench589. And, agree with you C6Bill about the frame as its been my guess from the get-go that the frame and along with the thinner gauge sheetmetal used in this generation as Wrench stated "excites" or amplifies the conditions created by out of spec parts. What's odd though (to me) is that I've read that for the new generation 2018 truck GM is designing an even stronger and stiffer frame. However, I have also read that GM will be utilizing primarily aluminum to skin the truck. If true, maybe the aluminum sheet metal might mitigate the vibration? Guess we shall see. 2018's will be out you know it....

C6Bill · January 6, 2017

Just a guess but I'm thinking they will leave the floor of the bed steel, that way they don't have to explain away the commercial bashing Ford for that lol

Austin66 · January 6, 2017

Has anyone actually jacked up the rear and run it and seen/heard/gauged this so called warped axle flange?

Snoringbear · January 6, 2017

Just a guess but I'm thinking they will leave the floor of the bed steel, that way they don't have to explain away the commercial bashing Ford for that lol

Lol, yeah, thought about that. I've read that although Ford is advertising their weight savings by using aluminum is 700 lbs the actual net net savings is about 100 lbs. I think that's where the stronger/stiffer frame comes into play on the 2018 models. I know that Ford has switched to an aluminum skin on their Super Duty line and has also used most of their weight savings on beefing up the frame to compensate. Btw, had lunch at Frisco Babes a few days ago. Thought about you, ate a chicken wing in your behalf

Snoringbear · January 6, 2017

Wow, this thread is coming up on 700 pages. Surely this is a forum record? If so, rdnckhntr94, as our beloved moderator, shouldn't you commemorate this milestone is some fashion ?