ColoradoBob
ColoradoBob New Reader
7/12/21 1:33 p.m.

I have a 2008 Suburban 2500 with the 14 bolt full floater 10.5 inch rear end.  This a common rear end in lots of tow vehicles so I'm hoping the GRM experts can provide some insight and assistance with an issue 

The truck has just under 150k miles and has developed a speed dependent whine that we've determined is coming from the rear axle.  I drained the fluid, pulled the calipers and axles and found the hubs on most sides were loose, meaning the hubs would rattle when you pushed in and out on them.  The keys and retaining rings were correctly installed but the nuts were way too loose.  Manual says to tighten the hubs nut to 50 ft lbs, then back it off and make it finger tight.  When properly adjusted there should be no play.

I figured I'd pull the hubs, replace the bearings and see if the noise goes away.  The problem is the hub I'm most suspicious about won't come off.  I found online videos that indicated they can require some force to get off, but this one won't budge.  It's tough to get ahold of the hub to pull on it so I made an adapter to attach a slide hammer, but after several hits it didn't move.  I limited how hard I hit it with the slide hammer for fear of damaging something.

At this point I've reassembled everything and put in new fluid.  The whine seems to be about the same as before.

I've changed the hub seals on two other similar axles (one was a 10.5, the other was an 11.5) so I am somewhat familiar with them but no expert.  In both cases the hubs came off without much effort.

Is this a normal situation and am I just not applying enough force to get the hub off?  Does the difficulty in getting the hub off indicate the bearing may be seized to the axle tube?

How do you recommend I proceed from here?

Any insight would be greatly appreciated

Thank you

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
7/12/21 2:21 p.m.

It's been many moons since I had mine apart, but I recall that it's pretty straight forward.  Even if the bearing were seized, the inner bearing is on the inboard side.  Do you have an idea of what's stuck?  Seal?  

If that doesn't cure your whine, check backlash on the ring.  It's easy to adjust on a 14 with the threaded races, but you're on borrowed time.  If they need adjustment, it means they're worn out.  Easy to replace and re-set lash with the way the races work in those.

ColoradoBob
ColoradoBob New Reader
7/12/21 3:13 p.m.

Curtis - Thank you for the response.  I can't tell what is stuck as it doesn't move very far.  Based on the design as I understand it it's either the seal or the inner bearing

I had the cover off and everything looked ok inside.  I didn't measure the bashlash so can't say if it's within spec.  There was some metal dust on the magnet but it didn't seem excessive, but I have limited experience with these rear ends so I'm not sure what's considered normal

ColoradoBob
ColoradoBob New Reader
7/12/21 3:22 p.m.

One other piece of information.  There was a tiny metal burr on outside edge each of the ring gear teeth.  The surface of the teeth looked and felt fine and while I didn't measure backlash, I didn't feel any.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
7/12/21 7:15 p.m.

Some replacement hubs have a spot for a snap ring to retain the inner race, but that wouldn't cause this.

I'm assuming disc brakes, right?  Cause drums can easily get a rust ridge worn in them that catches on the shoes.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/12/21 7:43 p.m.

They sometimes need a little percussive assistance to slide off.  A little, not giant screaming thwacks.

ColoradoBob
ColoradoBob New Reader
7/12/21 10:05 p.m.

Curtis - Definitely factory disc brakes.  I had an older version with drums that we converted to discs.  Drums were huge and insanely heavy.  

Pete - That's what I thought as well, that's why I'm concerned.  Maybe I'm just not using enough force.

ColoradoBob
ColoradoBob New Reader
7/14/21 11:16 a.m.

I was able to confirm that the whine doesn't change when varying throttle position.  I'm hoping that means the issue is with one or both wheel bearings, not with the ring/pinion and associated bearings.  Next step is to again try to get the hubs off

ColoradoBob
ColoradoBob New Reader
7/22/21 11:12 a.m.

I got the hub off using a slide hammer.  The seal between the hub and the axle housing is a two piece design and the hub half stayed with the hub and the axle housing half stayed with the axle housing.  So pulling the hub off required ripping the seal apart

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
7/25/21 11:46 a.m.

I'm not specifically remembering the seal design, but my drums might be different.

Glad you got it apart.

ShawnG
ShawnG UltimaDork
7/25/21 1:44 p.m.
ColoradoBob said:

I got the hub off using a slide hammer.  The seal between the hub and the axle housing is a two piece design and the hub half stayed with the hub and the axle housing half stayed with the axle housing.  So pulling the hub off required ripping the seal apart

Pretty common design nowadays. Seal was due to be changed anyway, don't sweat it.

81cpcamaro
81cpcamaro Dork
7/25/21 2:42 p.m.

My 2003 Burb rear seals did the same, they pretty much come apart in 2 parts. New seals were 1 piece and worked just fine.

ColoradoBob
ColoradoBob New Reader
7/30/21 12:14 p.m.

Seals and bearings are now replaced on both sides.  The seals on both sides came apart the same way so I suspect it's common

Thank you for the comments

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