2014 Silverado 1500 - Axle Noise - Just covering my bases

[ZombieK5]

Our 16yr old just got a 2014 Chevy High Country 1500.

We test drove it and there were no rear end issues (no vibration or clunking) while going up and down the 45mph Main Street...BUT we found the driver side axle tube (at the end) was covered in oil and caked dirt. The backing plate was covered too. The oil has been there for awhile, you can just tell its been there awhile. So...axle seal needs replacement.

Fast forward to tonight. On the highway we got a significant vibration from 55mph and UP. Vibration when on the gas (even just a little bit). LET OFF the gas and vibration goes away.

The vibration does not change when the transmission drops gear from Overdrive to 3rd gear (or is it 4th gear).

I have not opened the differential to see HOW MUCH oil is in there or if it is full of glitter. I am assuming the seeping axle seal has caused the oil level to drop. I realize that if the level goes down enough the axle end bearings might get dry and go bad. BUT will dry end bearings cause a vibration under load??

My main worry is the carrier bearings are bad (UGHHHHH) or WORSE, the Pinion is BAD TOO!

Any thoughts??

Next week I hope to get it on the lift and start pulling stuff apart.

 

[Wes Harden]

this the rear axle ? last time I had an unusual vibration the t case was in 4wh and above 55 mph

 

[Chickntrk]

2014 my money would be on transmission torque converter shudder, that’s how it starts then it goes boom

 

[ZombieK5]

this the rear axle ? last time I had an unusual vibration the t case was in 4wh and above 55 mph

Definitely wasn't in 4wd. ONLY happened on light acceleration and immediately stopped the instant the gas pedal was released.

 

[ZombieK5]

2014 my money would be on transmission torque converter shudder, that’s how it starts then it goes boom

I'm not thinking it's that. The RPMs at 55-65mph was between 1750 and 2100. That same RPM at lower speeds had zero vibration. Only happens at higher speeds.

 

[ktmoutfront]

Drive shaft u-joints?

 

[ZombieK5]

Drive shaft u-joints?

Possibly but they don't have any play when truck is parked. Id also expect a sound from the driveshaft when shifting from Drive to Reverse.

 

[Wes Harden]

double check u bolt are tight

 

[Blue85]

You can't tell anything about the driveshaft U-joints until you pick the rear end off the ground. Also helps to be in neutral. This also lets you check for play in the pinion from a loose pinion nut, which can also cause this problem. Check that stuff and check the oil before you start chasing the tough stuff.

 

[AJMBLAZER]

14-18 trucks the 9.5” AAMCo axles had bad luck with out of balance axle shafts.

 

[ZombieK5]

14-18 trucks the 9.5” AAMCo axles had bad luck with out of balance axle shafts.

huh? WTF?

Any remedies for this? Buy new axle shafts? Are there aftermarket sources?

I am fully versed in the Squarebody vendor and part sources but these new trucks are a maze. I cant even find a video showing the rebuild for these axles.

 

[AJMBLAZER]

Yeah, several companies make replacement shafts for them.

If you dig around over on https://www.silveradosierra.com/ there were a lot of threads about it in those years.

The 9.5” 12 bolt is basically a modernized 14 bolt semifloater.

 

[ZombieK5]

I'm too busy to deal with the 2014 now. I have the 1990 Silverado on the car lift getting a ton of work done. I am dropping the 2014 off at the dealer for a full diagnosis of all issues. IF it is the driveshaft or rear end, I will have them do that work. I am certain (85%) the rear main is leaking. I bought the rear main seal assembly just in case. I will do that work my self. Will update once Chevy gets back to me.