GM IFS 8.25 axle stub play - is it time to rebuild?

[marioski]

Hey Everyone,

First time poster! I stumbled across this site in search of looking for more info on the Gm 8.25 IFS and came across two awesome how-to threads (removing and rebuilding the ifs). I figured I would post a question before deciding to move forward.

My truck is an 07 Avalanche LTZ with the 8.25 IFS and 124k miles on it. In the past 7-8K miles I've noticed a humming sound that increases with speed. It's a humming sound that goes up and down with tone. Immediately suspected a front hub, but it didn't go away when I turned left or right and there was no play. Also my cv shafts are new along with the entire front suspension (lower/uppers/bushings). This week, crawling under the truck to do a visual I noticed the stub axle shaft has some significant play/wobble action. It's has to be the culprit as I figured there can not be that much play. I couldn't find any info on this online and used my buddies 08 Avalanche with the same case to compare. It has a similar wobble but a lot less play. It could be that his is developing the same issue, I just don't know, but it doesn't seem right to me.

So the question is, the drivers side stub axle, should it have any type of wobbling movement/play in it? There is no oil leaking out of it, so it's not affecting the seal. However I'm thinking the support bearing it rides on is starting to let go. Is it time to yank it out and do a rebuild on it or is this pretty normal for these diffs?

Here's a short video clip of what I'm referring to.
GM IFS - YouTube

Any thoughts would be great.

 

[Black02Silverado]

I would think that any "play" in the shaft as you described is not a good thing. Jarrod on here who did the writeup is pretty busy but should chime in. He is the man on these IFS.

Oh, and welcome to TMC.

 

[dirtyoldman]

I would think any play is a bad thing,I'll go check mine and report back in a few.

Love the vid,easy to see what you're describing

Oh,and welcome to TMC.Stick around I guaranty you'll like us

 

[Zembonez]

Way too much side to side movement in that flange. It should move but only a very small bit. Looks like you may have found your noise. Doubtful that the whole unit needs rebuilding. Probably just needs the side bearings replaced.

 

[marioski]

I'll definitely stick around as I trolled thru the site last night at work and there seems to be a great community here and tons of useful help and advice. Couldn't have used this site last week when I was dropping a fuel tank on my dad's 99 Tahoe.

I'm thinking the same thing on the play, there shouldn't be any, but before I take the time to pull the IFS out and spend money to have it rebuild I want to make sure of it.

 

[Hickspanic]

I would think that any "play" in the shaft as you described is not a good thing. Jarrod on here who did the right up is pretty busy but should chime in. He is the man on these IFS.

Oh, and welcome to TMC.

his left up was better though

 

[Hickspanic]

Welcome to

 

[Zembonez]

I'll definitely stick around as I trolled thru the site last night at work and there seems to be a great community here and tons of useful help and advice. Couldn't have used this site last week when I was dropping a fuel tank on my dad's 99 Tahoe.

I'm thinking the same thing on the play, there shouldn't be any, but before I take the time to pull the IFS out and spend money to have it rebuild I want to make sure of it.

No way that much play is normal. It would cause driveline vibrations (and wear) in the drive axle.

Might be worth having a GM tech take a quick look and offer up an opinion before you tear into it.

Thanks for coming on board. This place is nuts.

 

[dirtyoldman]

Just check my diff.....no play at all except for the side to side play of the gear mesh.

 

[Black02Silverado]

I would think that any "play" in the shaft as you described is not a good thing. Jarrod on here who did the right up is pretty busy but should chime in. He is the man on these IFS.

Oh, and welcome to TMC.

his left up was better though

I see what you did there!