Shake or Vibration Issues

mikegmi2 · September 29, 2015

My intention was to measure backlash, While I was rotating the case measuring runout I noticed the chips in 4 teeth took pictures and stopped there. Measuring the backlash on 41 teeth is a PITA especially on a hypoid gear tooth. Spec for back lash I believe is .007-.013" with .008" being ideal, and the difference in backlash between teeth is .003" or less. I called the service manager and gave home the whole run down of it being put on the PICO but being below GM spec, so they vector matched and RF balanced the tires but it didn't solve the problem, I told him I opened up the diff and found chips and took some pictures and asked if he wanted me to email them to him so they could decide how they wanted to proceed, He said bring it in first thing tomorrow morning. The truck is in at the dealer as I type this, waiting for a phone call to see what they have decided to do.

For the record, on my 2014 they gave me the measurements and mine ranged from .007 - .0011 and they replaced the entire rear axle assembly. I didn't get the measurements on my 2015 but that was also replaced 2 weeks ago.

14silverado4.3 · September 29, 2015

My intention was to measure backlash, While I was rotating the case measuring runout I noticed the chips in 4 teeth took pictures and stopped there. Measuring the backlash on 41 teeth is a PITA especially on a hypoid gear tooth. Spec for back lash I believe is .007-.013" with .008" being ideal, and the difference in backlash between teeth is .003" or less. I called the service manager and gave home the whole run down of it being put on the PICO but being below GM spec, so they vector matched and RF balanced the tires but it didn't solve the problem, I told him I opened up the diff and found chips and took some pictures and asked if he wanted me to email them to him so they could decide how they wanted to proceed, He said bring it in first thing tomorrow morning. The truck is in at the dealer as I type this, waiting for a phone call to see what they have decided to do.

Please keep us updated.

I am sure they will find this normal wear and tear for the 2014.

abominable z71 · September 29, 2015

Please keep us updated.

I am sure they will find this normal wear and tear for the 2014.

Just got a phone call. Nothing wrong with the gear, that small chip is not in the contact pattern and does not affect performance, backlash is fine, gear pattern is fine, nothing more we can do. He did say the area rep is going to be at the dealership today and he's going to try and have him drive the truck with the PICO scope even though last test with the PICO said vibration is below the limit. The service manager has actually been really good pushing the boundaries of what he's allowed to do under GM's warranty. When it's all said and done I'll probably be told operating within spec and sent vibrating down the road. If that's the case this will be the last GM product I purchase.

OmahaBen · September 29, 2015

When it's all said and done I'll probably be told operating within spec and sent vibrating down the road. If that's the case this will be the last GM product I purchase.

Keep pushing. They finally got approval on mine to pop the cover and check the backlash in my differential, they drove it and the pico meter and found it was out of spec. I did have to take it to another dealer.

We will see what happens. I have been given 4 different trucks as loaners. All being GMC 1500 2015 models and 3 of the 4 vibrated worse than my 2014. One was smooth as can be.

I can't see how GM can ignore this issue and keep truck customers. If you can feel a driveline vibration, pico meter or not something is wrong.

Edited September 29, 2015 by OmahaBen

14silverado4.3 · September 29, 2015

So who is OEM supplier for the ring and pinion gears for GM?

abominable z71 · September 29, 2015

So who is OEM supplier for the ring and pinion gears for GM?

The entire rear end and front diff for the matter is built by AAM a former subsidiary of GM, they are the oem supplier for all three major domestics on at least some models.

Jesse Davidson · September 29, 2015

The entire rear end and front diff for the matter is built by AAM a former subsidiary of GM, they are the oem supplier for all three major domestics on at least some models.

well thats not good hahaha

LongrangeLauber · September 29, 2015

Another update on truck: the road force balance solved it for about 3k miles or so. Was doing a lot of highway driving today and around 68mph I get a slight vibe and about 77 I have a vibe in the steering wheel and seat (not as bad as before though). Anything above 65 mph and the passenger seat shakes like crazy like it did before. Getting mad again lol

Jesse Davidson · September 29, 2015

Another update on truck: the road force balance solved it for about 3k miles or so. Was doing a lot of highway driving today and around 68mph I get a slight vibe and about 77 I have a vibe in the steering wheel and seat (not as bad as before though). Anything above 65 mph and the passenger seat shakes like crazy like it did before. Getting mad again lol

Atleast yours was fixed for a little while, mine has never been fixed

LongrangeLauber · September 29, 2015

Atleast yours was fixed for a little while, mine has never been fixed

At least you don't get your hopes up then it comes back haha

Jesse Davidson · September 29, 2015

At least you don't get your hopes up then it comes back haha

hahahahaha, I actually laughed at this one. touche my friend, touche hahaha

abominable z71 · September 30, 2015

No problem, Operating within spec, what a joke. F@!K GM, I will never buy another GM product, should have never bailed their sorry a$$ out and let their crappy products go under with the rest of the company.

thrasher2010 · September 30, 2015

My 2014 Silverado has just under 20k miles and is starting to get worse.. It's been doing since about 7k miles.. I have been to 2 different dealers and the both state that there is nothing wrong with it.. Not sure what my options are now.. I have pressed the issue but still get no where..

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Wrench589 · September 30, 2015

For the record, on my 2014 they gave me the measurements and mine ranged from .007 - .0011 and they replaced the entire rear axle assembly. I didn't get the measurements on my 2015 but that was also replaced 2 weeks ago.

.007" to .011" being out of spec makes more sense than .007" to 013" being spec because somewhere there was a post that these vehicles have the newer technology "2-cut" gear sets which run a tighter backlash - in the .004" to .008 with .006 being optimal. So, variation between teeth would also need to be pretty tight I suspect. Now, I have no idea what GM spec is, and it would be wildly speculative to think that the factory was setting them up "the old way", with too much backlash for the new design. But does make you wonder WTF is going on.

That said, those chips on the edge of the tooth is highly suspect. OK, it's not in the contact pattern. What the heck chipped it, then? Is the gear that poorly made that the pieces fell out on their own? That is not comforting!! Either way, it's crazy.

Someone needs to get brave and install an aftermarket set of gears and see what happens. It looks like Yukon Gear and Axle are making them for 2014 and 2015's now. Although not 100% sure from the website! as there are no actual part numbers or ratios listed. Certainly wouldn't buy a set from AAM!!

Edited September 30, 2015 by Wrench589

jmckeone · September 30, 2015

For those of you who have been through arbitration I just got this letter back from the BBB. Im not sure if it means my case is going to arbitration or if its still pending. Anyone know what to expect?

Edited September 30, 2015 by jmckeone