2015 Axle Shaft Lateral Runout

coker6365

Coker6303's ***** Daddy
Dec 4, 2011
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I have been fighting the dreaded vibration since day one on my 2015 Denali. 3 sets of tires, 5 road force balances, and an ongoing law case later... the problem still exists and gets worse with a load.

I may have stumbled across something that could be a potential problem. The rear wheel lateral runout is roughly .024" on the driver side and .014 on the passenger side. So I figured, let's check the hub since I have already checked the wheels on a hunter machine which came out to .003" at the worst. The hub was showing .010" lateral runout. I found that odd as the bearings were tight and there were no signs of abnormal wear. So I pulled the axle shaft out and checked the runout on the hub again... showed .002" at the worst. As soon as the axle shaft is torqued down, the runout jumps to .010 or worse. Once the high side was found, the axle shaft could be torqued down with .006" runout using 1 bolt. As soon as any of the other bolts were torqued, you could see the gap in the gasket close and the runout immediately went over .010".

I am debating on replacing the axle shafts at my cost to fix the issue as I am tired of fighting with the dealership over it time and time again. I pulled the shafts out and rigged up seals for the end caps so I could run down the road in 4wd and have minimal lateral runout on the rear. The problem seemed to disappear, but more diagnosing is in order before parts are ordered.

Can anyone check their hub runout and compare their findings to mine? Also, will the axle shafts out of an 06 fit the 2015?
 
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quadracer37

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Mar 31, 2009
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In regards to your last question, no the 01-10 model axles WILL NOT fit on your 15. You'll need shafts from an 11-15 model. I have a used set from an 11 if your interested in testing your theory, vs buying brand new parts.
 

coker6365

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Dec 4, 2011
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I appreciate the help, but i have already narrowed it down further. At this point, it is the pinion yoke, pinion, or ring gear. I pulled the axle shafts and the vibration is still there. Swapped driveshafts and it stayed the same. Pulled the drive shaft and the vibration disappeared. So i ordered a new yoke and went ahead and got that axle shaft anyway. As much as it moves, it wont hurt to replace it.

Thanks for the help!
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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i wouldnt think a pinion flange would cause it unless the new trucks still have the big balancer looking deal on the flange like the older trucks
 

coker6365

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i wouldnt think a pinion flange would cause it unless the new trucks still have the big balancer looking deal on the flange like the older trucks

Yup, still has the balancer on the yoke. I wouldnt think thats the problem, bit that is the direction the diagnosis is sending me.
 

Chevy1925

don't know sh!t about IFS
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out of curiousity, what is the pinion angle and what is the t-case output shaft angle?
 

coker6365

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Check the carrier bearing?

It's a one piece, no carrier bearing to worry about.

out of curiousity, what is the pinion angle and what is the t-case output shaft angle?

Originally, the shaft was 6*, trans was 4*, and the pinion was 7*. I added 2* shims to drop the pinion to a better angle and there was zero change in the vibration so I didn't bother getting the angles after the shims. The shims will be removed when the pinion and yoke arrive.
 

Chevy1925

don't know sh!t about IFS
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What if you just swap the whole rear end from your 06 under it and go for a drive?

I don't feel the yoke will fix it. If it were that, it should still vib with the driveshaft out. Your vib seems to be coming from a light load condition when the axle is powered. But I have no idea what to tell you to check next. Maybe pull he diff cover and check the ring and pinion for odd wear? Or the carrier bearings?

This is strange.
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
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My buddy is still fighting this issue as well. I thought he said he had licked it but I was wrong. He did have his drive shaft checked and it was within spec. I told him about your idea and he is going to start looking into his axle as well. This fella is persistant so I will keep you posted as to what he finds. He did tell me yall are not alone in this, apparently there is a thread about it on gm trucks...
 

coker6365

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Dec 4, 2011
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Update...

I centered the front u-joint, had the driveshaft rebalance at 3000 rpms (even swapped a known good driveshaft to check it), replaced the pinion yoke, and replaced the driver side axle shaft. Vibration is still there with zero change!!! The wheel movement or lateral runout is gone, but it is not the issue. I still have a lot of movement on the yoke balancer, which has me thinking maybe I need to try it without the balancer after inspecting the ring/pinion.

Moving to the ring/pinion next... then maybe the t-case output shaft.
 

coker6303

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Aug 6, 2009
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Sucks! I told him all these great things about a Duramax, and sure enough he gets one with a lingering, annoying issue :mad: