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Rear Axle in/out play 08 LTZ 258k

nyjumpee

Full Member
Joined
Jun 20, 2010
Messages
49
I've done a search online and this forum and don't see anything that exactly addresses this (at least not that I've seen). I changed all 4 tires on my 2008 LTZ. Putting the rear passenger wheel back on and noticed I can pull the wheel in/out about 1/16" - 1/8". The rear drivers side doesn't move nearly as much although it has a tiny amount of movement in and out. There's no up/down or side to side movement which I think would indicate bad wheel bearings? My online research did mention the possibility of C-Clip wear on the end of the axle? I don't notice any effects driving. . just don't want to let it go if it could turn bad. . .

Here's a link to it on Google Photos/Video: https://photos.app.goo.gl/uvuFLpoxkXoS5Gsi7

Thanks!
 
I'm not personally aware at how much play is normal there. The passenger side axle shaft is the longer of the two and AFAIK has a little bit more play because of how it interacts with the differential. I dont think it's of major concern to you as long as you're keeping your rear diff oil maintained.

If you wanted to check it out/ replace it for peace of mind, id just go ahead and do both sides and all parts at once, as they're directly related.

you have to get in and remove those clips in order to take the shafts out and change the bearings. You're already going to want to take the wheels off even just for the clips, so it's not a lot further to go ahead and replace the bearings and seals while you're at it.
 
Hey Raekal ~ thanks for your input! I also hear a humming sound, like a bearing but I'm not sure exactly where it's coming from. None of it is pronounced or causing an issue but since I use the truck for long road trips, I try to stay ahead of any problems that'll leave me stranded. I'm going to my trusted mechanic this morning (I was supposed to be leaving on the trip this morning) just to see if he can quickly diagnose it and if it needs immediate attention.

If I were to do the rear-diff rebuild, exactly which parts would I be replacing? Bearings, seals and C-clips? Have you done this job? I've seen videos of similar Diffs but not necessarily an 08 Avalanche diff. Looks like either way I'd be renting/borrowing a bearing puller and maybe a few other specialized tools? Thanks again!

PS Just a thought but has anyone ever thought of putting a drain plug on the Diff cover plate or some other way to change the fluid without have to pull the cover?
 
IF you never done a rear end rebuild you can do more damage then good if you do not have someone around who has done it before the correct way.
As you have bearing and gear clearances and preloads which are important for life and reduced noise.

Best left to experts IMHO
 
Thanks for the link to the covers with the drain plug in there. . and also for the input on the complexity of rebuilding the rear diff with clearances and preloads, etc. It was definitely a can of worms that I didn't want to open. . .I'll just stick with pulling the cover and replacing the fluid and if I see anything obvious or still suspect an issue I'll take it to a trusted mechanic. Thanks again! PS Any recommendation on specific fluid I should be putting in there e.g. brand and viscosity? Thanks again.
 
Thanks for the link to the covers with the drain plug in there. . and also for the input on the complexity of rebuilding the rear diff with clearances and preloads, etc. It was definitely a can of worms that I didn't want to open. . .I'll just stick with pulling the cover and replacing the fluid and if I see anything obvious or still suspect an issue I'll take it to a trusted mechanic. Thanks again! PS Any recommendation on specific fluid I should be putting in there e.g. brand and viscosity? Thanks again.
Just about any 75w-90 synthetic oil will do for the rear, personally I put amsoil severe gear in mine. But that's a bit cost prohibitive if you're not looking to use them for everything. (membership discounts).

Realistically, just stick to whatever speaks to you on the shelf/ amazon/ ect. You do tend to get what you pay for when it comes to wear additives though.

Edit: looks like limited slip additive isnt required for the limited slip rear ends. It's been a little while since i've serviced one of those myself.
 
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Hey Raekal ~ Thanks again for your input. I also didn't know about "wear additives". Do I need that in addition to the 75w-90 oil? In all of my research this is the first I've heard of a wear additive and your post makes it sound almost necessary. Thanks again :)
PS As far as I know, I have no issues with my rear diff like chattering, noise, etc. Only posted initially cause I wasn't sure about the in/out play on the rear passenger axle. Also, I know it hasn't been changed since I'VE had the truck ~ I got it at 80k and now has 258k (I know. . .bad. .bad. . .bad. .)
 
Hey Raekal ~ Thanks again for your input. I also didn't know about "wear additives". Do I need that in addition to the 75w-90 oil? In all of my research this is the first I've heard of a wear additive and your post makes it sound almost necessary. Thanks again :)
PS As far as I know, I have no issues with my rear diff like chattering, noise, etc. Only posted initially cause I wasn't sure about the in/out play on the rear passenger axle. Also, I know it hasn't been changed since I'VE had the truck ~ I got it at 80k and now has 258k (I know. . .bad. .bad. . .bad. .)
Wear additives are part of the oil, just like cleaning additives in gasoline. While many believe that oil is just oil, the extra additives a company puts in it can have significant long term wear prevention. And at least as far as motor oil is concerned, amsoil seems to knock it out of the park.

Cost doesn't mean everything for motor oil, some of the store brand synthetics (amazon, cost co, ect) can outperform some of the lower name brands. But when it comes to gear oil, you realistically just have name brand vs generics there isnt a ton of competition.

Differentials are also much simpler than engines and dont get nearly as hot. So one could argue that you dont need to go super fancy with it. Just make sure it's a synthetic oil.


I edited my previous post likely after you read it, i removed the bit about the LSD additive, it isnt needed as far as your truck is concerned. It's always something to check with limited slips, some still need it. It's a friction additive that helps the clutch pack work. Oil is slippery, and clutches use friction, so it's a common additive to aid that. When those differentials dont have it, they can slip and 'chatter' as they struggle to gain traction. But again, you dont need it.
 
Thanks again for your quick replies and info. Since I literally NEVER change the diff oil, I won't spare the expense and make sure I get a good name-brand oil. Thanks again ;-)
 
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