Shake or Vibration Issues

[Snoringbear]

I'm having an Air Lift system installed January 12th. My truck doesn't have the notorious "Chevy Shake". So, can't comment on that. I'm having the install done for towing. However, I've talked to some people who've had the install done and they say that when driving about with no load and with a minimal amount of air in the bags, just enough to take the weight slightly off the rear springs, it reduces jounce that is common with leaf springs. If so, that alone will be worth the install as the soil here in the DFW area is black gumbo and expands and contracts significantly depending on rain and drought conditions causing the roads to buckle badly. Anyway, I'll give feedback on the system once I use it some, make a tow, etc.

[Schmidt152]

Yeah mine said that in sorts and I called bullshit when I made him ride with me in an on the lot used 2012 and it was perfect! I do have something else I'm gonna try and that is to take a diff carrier with ring gear installed and check runout on the outer portion of the gear and then check balance. Some have stated the ring gear was their issue and gm did a gear change. Soooooo on to the next step. BTW i found that the out of round axle flanges that I just tested had over 18 grams of weight that i turned off of the axle that i trued up. That's a helluva lot!

 

RT

RT are you still having issues with vibration? I thought yours was resolved?

Happy New Year Everyone

[Mark Diedrich]

 

 

Just to update everyone on the rumble strip vibrations I was experiencing. I got the truck back 2 days ago and so far so good. Here is what the dealer reported:

 

Road tested vehicle and found possible tire/wheel vibration. Removed all four wheels and road force balanced to find one tire out of range. This tire was replaced and then vehicle was road tested again. The vibration improved but was not eliminated. Checked for TSB's and none were found that directly addressed this concern. Contacted TAC and TAC suggested to utilize TBS PIP5149B. I followed all instructions of this TSB, checking for excessive spark retardation and connecting rod oil squitter condition. There were no conditions observed. TAC then directed me to utilize DOC ID#2102430 where I checked the operation of the control solenoid within the transmission. When commended to the on position, It registered full pressure and when commanded off it registered 0 pressure. After completing all tests found that TCM could not be 'pulse-width' tested, only command on or off. With these measurements we determined that the TCM was sending an erratic signal causing the torque converter to be commanded erratically. This caused potential damage to torque converter. Therefore, I replaced the TCM (Signal) and torque converter (damaged internally). Road tested vehicle; now operating to GM specifications with no vibration when tested under the original conditions.

 

I have also noticed that the "floating Tac" condition I had earlier is no longer present.

[Mark Diedrich]

Brandon, I think you might be my hero!

Mine feels like rumble strips on occasion and my TAC bounces on occasion to with the cruise!

I'm going to take your diagnose into the dealer.

And drives perfect the rest of the time....

[Jesse Davidson]

Yeah mine said that in sorts and I called bullshit when I made him ride with me in an on the lot used 2012 and it was perfect! I do have something else I'm gonna try and that is to take a diff carrier with ring gear installed and check runout on the outer portion of the gear and then check balance. Some have stated the ring gear was their issue and gm did a gear change. Soooooo on to the next step. BTW i found that the out of round axle flanges that I just tested had over 18 grams of weight that i turned off of the axle that i trued up. That's a helluva lot!

 

RT

 

 

 

18 grams? That's like a half ounce of "Pot" A 5,000 pound+ Truck with 1/2 ounce of pot on one side vs the other? Really, I am going to the garage to burn one because now I have officially heard it all. I can't comment any more on this sorry@

18 grams of weight on an axle flange translates to roughly 25lbf based on 2000RPM, which will increase exponentially as RPM increases

[07Softail]

RT are you still having issues with vibration? I thought yours was resolved?

Happy New Year Everyone

At 100-118 a little shimmy and up around 140 it was a pretty good vibration but after cutting the axles it's damn near perfect. The driveshaft truing fixed 96% of it. Sorry for getting pissy with the Pot smoker but I'm not taking this subject lightly, and further more someone questioning my competency as a 30 year Machinist kinda set me off a bit. As I stated in C6Bills post I will be checking the ring gear runout not that mine needs any more tweaking if it's off I will clean it up and if not i'm satisfied. Just trying to help everyone out guys.

 

RT

[07Softail]

 

 

18 grams of weight on an axle flange translates to roughly 25lbf based on 2000RPM, which will increase exponentially as RPM increases

I knew the pot smoker couldn't figure that one out, it's some people you just can't reach! I worked at an automotive machine shop for 10 years and 4-7 grams on a connecting rod and crankshaft counterweight was ok by factory standards but not in the HP engine building world.

 

RT

[Schmidt152]

I think most of us appreciate the information, RT. This problem sucks and I'm finding myself wasting roughly 2 hours a day researching. I'm still waiting on a GM engineer to get back to me.. Only thing that I noticed that differed from your experience is that my truck is perfectly smooth 55-60 MPH. So I'm wondering if i'm having a different problem than you. I have noticed the "floating Tac" that was just mentioned while driving down the road. Even at an idle it will bounce and my truck will shutter occasionally, which maybe another problem itself. I'm forwarding this information to my dealer as well.

Edited January 1, 2017 by Schmidt152

[07Softail]

Same issue just at different MPH because of the 4 different gear ratio options we have.

 

RT

[Rolling Thunder]

Same issue just at different MPH because of the 4 different gear ratio options we have.

 

RT

 

Could it also be the different gear ratios accompanied by different flange imbalances? In other words the same gear ratios vibrating at different speed because the flanges out-of-round varies?

[MRW412]

Here's an update on my truck since it has been 2 weeks since I installed Yukon Gear rear axles. The truck has been shake free since installing them. I have driven on multiple smooth highways at 70+ mph and no shaking.

Here's an update on my truck since it has been 2 weeks since I installed Yukon Gear rear axles. The truck has been shake free since installing them. I have driven on multiple smooth highways at 70+ mph and no shaking.

[07Softail]

 

Could it also be the different gear ratios accompanied by different flange imbalances? In other words the same gear ratios vibrating at different speed because the flanges out-of-round varies?

It sure could.

MRW412

Here's an update on my truck since it has been 2 weeks since I installed Yukon Gear rear axles. The truck has been shake free since installing them. I have driven on multiple smooth highways at 70+ mph and no shaking.

That is awesome.... I really think we are narrowing this vibe down!

RT

Edited January 2, 2017 by 07Softail

[Rolling Thunder]

It sure could.

 

RT

 

You analysis is very understandable but this post and fix makes my head spin:

 

http://www.gm-trucks.com/forums/topic/153186-shake-or-vibration-issues/page-692?do=findComment&comment=1913558

 

The bouncing tachometer RPM's fix is beyond many of us to fix and / or analyze.

[Schmidt152]

Here's an update on my truck since it has been 2 weeks since I installed Yukon Gear rear axles. The truck has been shake free since installing them. I have driven on multiple smooth highways at 70+ mph and no shaking.

Here's an update on my truck since it has been 2 weeks since I installed Yukon Gear rear axles. The truck has been shake free since installing them. I have driven on multiple smooth highways at 70+ mph and no shaking.

Could you give more specifics about your symptoms? Describe the vibration and location in the cab? Was it more noticeable in the steering wheel or seats or just a vibration throughout the truck in general?

[sdeeter19555]

After reading about the ring gear fix, wonder if they were cut right to begin with, not runout but actual tooth to tooth contact? Maybe not hardened correctly, some softer spots?

 

Interesting topic to follow...

 

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