2012 Suburban 1500 LT real axle bearings

Eric D Plante · July 3, 2018

Some history:

Limited towing. total of 5 times maybe with a 32 travel trailer.

approx 100k miles

Yokohama Geolander AT tires.

I noticed about 2 months ago a speed related low frequency howl, similar to driving with aggressive mudders. The noise doesn't change with accelerating vs decelerating. I 1st thought it was a front wheel bearing but the more I listened for it and asking my son in the 3rd row he said it was from right below him. I have no issue with replacing the rear axle bearings, that doesn't mean I want to do them just for the hell of it. Has anyone else had a similar experience?

diyer2 · July 3, 2018

Were the rear end fluids changed?

How far did you tow the 32 footer?

Tongue weight of the 32 footer?

Did the burb squat when towing.

Maybe to much tongue weight.

Or you just got unlucky.

Eric D Plante · July 3, 2018

Got the truck with approx 65k on the odometer. I have no previous history so I have to assume the fluids had not been changed prior to owning it, and I have not changed the fluid yet either

I had towed it from Sc to Boston, Boston to the white mountains and back once and then about an hour north and back.

approx 550lbs

no I had a Weight Distribution hitch installed and properly setup.

1 test I was going to perform was put the rear end up on jack stands, chock the front wheels of course. Put it in drive and accelerate to see if I can replicate the noise. Yes its a bit risky and I have to disable traction control, stabilitrack and such.

no HD · July 3, 2018

Check your universal joints.

Eric D Plante · July 3, 2018

I did that. I am not getting a vibrations. FYI its just 2wd.

Eric D Plante · July 3, 2018

I am fairly confident its the axle bearings but I'd like some confirmation from someone with similar experience.

Edited July 5, 2018 by Eric D Plante

Supreme Pizza · July 3, 2018

Here is what I would do:

Check your diff fluid level, it may be low.

Drive the truck around the block, but don't go far enough to heat up the diff. You want the gear oil mixed up, but not warm.

Stick a strip of white cloth into the fill plug hole (don't let go of cloth) . Remove the strip of cloth, and inspect it in direct sunlight. Any metal in the oil?

You can also run the cloth over a magnet to see whats there.

Many times, people don't fill the diff properly. They fill it to the bottom of the hole, and immediately put the plug in. You need to let it sit for 5 minutes and then check the level again. The oil flows out into the axle, and the level drops. Cold oil doesn't flow very fast, so you get a false full reading. Then you fry the bearings.

Hope this helps. Let us know what ya find out.

Edited July 3, 2018 by starman8tdc

Eric D Plante · July 5, 2018

Those are good tips. I'll check this weekend, when its not hot as shit out.

Eric D Plante · August 31, 2018

OK here is an update:

Axle bearings didn't fix the issue. The driver's side oil seal was leaking though.

So this meant I had to tear into the diff, wasn't thrilled about that. The magnet on the cover wasn't clean, no big metal pieces though, just silvery sludge. Pulled the center section, bearings looked good. Pulled the driveshaft off the pinion yoke, and found the pinion bearings were shot, WTF!!!!!!!! Picked up a rebuild kit from Advance auto, yeah wrong friggen bearings for the pinion, center section they were fine. Apparently in 09' GM changed the bore dimension and pinion shaft dimensions. WHY???? Order the same Koyo bearings I had removed from the pinion shaft. OH and I had to bring the center section and Pinion to the dealer to get the bearings off, I was getting nowhere real fast trying to press them off with a press. I found out they use a die grinder and and chisel to split the inner races. Once all that was done and I had the correct bearings pressed on the pinion cleaned everything with brake kleen and started to reassemble. Holy smokes that crush sleeve is tough to crush with hand tools. Eventually I got it set to approx 16 in/lbs or rotation drag. Reassembled the rest of it, filled it and all is good now. I am still disappointed that just over 100k the pinion bearings failed. Whats that all about.

swathdiver · September 1, 2018

7 hours ago, Eric D Plante said:

I am still disappointed that just over 100k the pinion bearings failed. Whats that all about.

The 8.6" differential is the weak link in our drivetrains. Gotta keep clean fluid at the proper level in them (2.15 Quarts) and watch your weights when towing. Even then, guys who regularly tow at or near maximum capacity wind up needing new center sections or other parts.

If this axle has problems again, consider the 9.5" AXN that bolts right up that was used on 2WD Avalanches and Escalades.

rkj__ · September 1, 2018

Be thankful you caught it when you did. Mine gave out on my Canyon in a more catastrophic manner, hours from home on a camping trip.

The bearing exploded, and bearing rollers were ejected into the differential. It went from sounding perfect, to terrible gear wine in about 400km. I’m probably lucky the gears did not lock up. It never left me stranded, which was nice.

I ended up getting an entire used axle swapped onto the truck at that point, at a dealer five and a half hours from home.

Sent from my iPhone using Tapatalk

mkimber · September 5, 2018

Good thing you figured it out. Off topic, but how well does your suburban handle that trailer? I currently tow a 25ft 4000lb camper but about to upgrade to a 30ft 6000 lb. It handles our current setup easily. Thanks!

Eric D Plante · September 6, 2018

On 9/5/2018 at 7:05 AM, mkimber said:

Good thing you figured it out. Off topic, but how well does your suburban handle that trailer? I currently tow a 25ft 4000lb camper but about to upgrade to a 30ft 6000 lb. It handles our current setup easily. Thanks!

When I towed with it it was fine, plenty of power vs my older 04' Z71 Suburban.

On 9/1/2018 at 4:17 AM, rkj__ said:

Be thankful you caught it when you did. Mine gave out on my Canyon in a more catastrophic manner, hours from home on a camping trip.

The bearing exploded, and bearing rollers were ejected into the differential. It went from sounding perfect, to terrible gear wine in about 400km. I’m probably lucky the gears did not lock up. It never left me stranded, which was nice.

I ended up getting an entire used axle swapped onto the truck at that point, at a dealer five and a half hours from home.

Sent from my iPhone using Tapatalk

My 04' Suburban had something similar. I let off the gas on when pulling onto an off ramp and heard the whine. We pulled into Florence SC with an 04' Suburban, pulled out 8 hours later in a 12' Suburban. LOL. I really think the 1/2 ton Suburbans are not the best option for reliable towing for the long run.

On 8/31/2018 at 9:36 PM, swathdiver said:

The 8.6" differential is the weak link in our drivetrains. Gotta keep clean fluid at the proper level in them (2.15 Quarts) and watch your weights when towing. Even then, guys who regularly tow at or near maximum capacity wind up needing new center sections or other parts.

If this axle has problems again, consider the 9.5" AXN that bolts right up that was used on 2WD Avalanches and Escalades.

That doesn't leave me with a warm fuzzy feeling. Having to change axle assemblies to get a reliable setup is kinda pathetic.