Rear-end swap: 8.6" 10 bolt w/3.08 >> 9.5" 14 bolt w/3.42 + 3.42 swap in 8.25" front (or else)

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Rear axle removal thread: https://www.tahoeyukonforum.com/threads/rear-axle-c-clip-removal-guidance.139472/


My goal is to order all the parts and tools necessary to make this happen by end of business today. Any advice, guidance or humor throughout this will be greatly appreciated.

Friday five days ago was the first time I'd ever seen the inside of a differential, and if I don't get this completed before our new kitchen gets here....I will likely be experiencing living inside a garage for the first time also:buttkick:


Anyone see any must have parts missing from this list? or any more job specific tools I will need?

{edit} -and-

Can anyone verify that I can or can't tell my ECU to make nice with the 3.42's with a Tech 2? Would love to have one but am leaning towards laptop and HP Tuners b/c I have to shut down the AFM and the TCC Lockup in 1st-4th, dial it back in 5th/6th as soon as I'm done with her kitchen; and I'm of belief? Tech 2 can't do the TCC??

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5StarCustmSolutns
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Can't change the TCC lockup or the gear ratio with a Tech 2, unfortunately.

Dang it..

I've got a 68.308mi 9.5 14 bolt tee'd up in your neck of the woods right now.. Well almost in your woods....Roanoke. Have about 20min to make a decision for a Friday pickup. I'll prob wait til morning and go get it Monday. I'm still licking my wounds from getting "got" for $170 right before Christmas on an Escalade instrument cluster :mad: . Plus the salesman was trying to pressure me, and thats exact wrong approach to me
 

Foggy

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You'll need HPTuners to do what you want in the transmission...
Believe Me, It makes a world of difference
I "believe" that you won't need any driveshaft/Ujoint/Pinion changes.. It should all just
bolt in... At least it does in the Yukons. (for the rear end)...
The HPT will do your DOD disable, your speedo (for new gears), and trans shift points
I love my 6L80E with it 'tuned' correctly... Stock it kinda sucked
 
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Had an interesting evening yesterday. I stumbled into the subject of carrier breaks.....and either the site I was looking at parts on was incorrect or I'd accidentally selected the wrong axle assembly to look at parts for? The Front Diff R&P gear prices I was seeing had this huge increase to jump the carrier break and go from 3.08 to 3.42? So I spent the next hour or so hour learning up on what a carrier break was(and what the hottest new winter trout lures are). But thinking about how limited my options just became and how expensive things just got for the front diff, I got aggravated....shut down computer, turned out the lights, and sulked my way in the house determined to sell the truck lol.
Then this morning I found this:


and it's got a much better description(with visual aids) of what a carrier break is and a list of which common axles have and don't have a break that affects this project.
I must've accidentally selected a GM 8.2 BOP instead of the 8.25 IFS?? That's the only thing I can figure?
Either way that link was relevant enough to this thread to include. Lot of good info on that site period
 
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When I first started using forums I didn't understand why the trend seemed to be to advise new members with questions to go read and find the answer themselves... I was also much younger at the time... After a little experience, I get it.... It's kind of like giving a man a fish and feeding him today or teaching a man to fish and feeding him for rest of his life

But right now, since my truck is on jackstands with differentials removed, I'm in need of a fish....or a really hot lure I can catch one pretty quickly on?

Currently in the middle of this 9.5" 14 bolt 3.42 front/rear swap on my 2011 Avalanche. Yest I purchased an 8.25" IFS 3.42 front diff. It looks like poo but I have it. Yest eve I made arrangements to pick up the 9.5" rear a couple hours from now. I mentioned the front I had just bought and it's condition to the owner of the yard I'm goin to today and he offered me the one out of the donor truck for $100 bones!?!? Told him I was of the belief the 9.25 was NOT a direct bolt up under the front of trucks that came w/8.25?? He says it is... However the yard yesterday said it was not?

So I'm getting conflicting answers from competing salvage yards?

If anyone knows about this, and is certain, would you please share your wisdom:

Is '07-13 9.25" front diff a direct bolt onto my 2011 Av that came w/the 8.25"? -and- If it does bolt on, are there any spline count, axle length/diameter, or hub fitment issues?

Sorry to ask, I'm dizzy from reading about this right now and am running out of time..
 
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avalonandl

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The avalanche (1500) and Tahoe/Yukon are built on the same chassis. Wheelbas is the diffence so mounting points are the same. 2500 a different animal
 

Geotrash

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When I first started using forums I didn't understand why the trend seemed to be to advise new members with questions to go read and find the answer themselves... I was also much younger at the time... After a little experience, I get it.... It's kind of like giving a man a fish and feeding him today or teaching a man to fish and feeding him for rest of his life

But right now, since my truck is on jackstands with differentials removed, I'm in need of a fish....or a really hot lure I can catch one pretty quickly on?

Currently in the middle of this 9.5" 14 bolt 3.42 front/rear swap on my 2011 Avalanche. Yest I purchased an 8.25" IFS 3.42 front diff. It looks like poo but I have it. Yest eve I made arrangements to pick up the 9.5" rear a couple hours from now. I mentioned the front I had just bought and it's condition to the owner of the yard I'm goin to today and he offered me the one out of the donor truck for $100 bones!?!? Told him I was of the belief the 9.25 was NOT a direct bolt up under the front of trucks that came w/8.25?? He says it is... However the yard yesterday said it was not?

So I'm getting conflicting answers from competing salvage yards?

If anyone knows about this, and is certain, would you please share your wisdom:

Is '07-13 9.25" front diff a direct bolt onto my 2011 Av that came w/the 8.25"? -and- If it does bolt on, are there any spline count, axle length/diameter, or hub fitment issues?

Sorry to ask, I'm dizzy from reading about this right now and am running out of time..
I'm confused. As far as I know, the 9.25" rear diff with the 6-bolt wheel hub flanges only came on 2WD half-ton Escalades and Denalis because of the higher torque output of the 6.2. If that's true, then I wouldn't expect there to be any front diff in that donor truck. Are you sure that the rear axle you're about to pick up has the 6-bolt hub flanges and came out of a 2WD Escalade or Denali?

And to answer your other question, no, a 9.25" front diff will not fit under a half-ton Avalanche, AFAIK.
 

randeez

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I'm confused. As far as I know, the 9.25" rear diff with the 6-bolt wheel hub flanges only came on 2WD half-ton Escalades and Denalis because of the higher torque output of the 6.2. If that's true, then I wouldn't expect there to be any front diff in that donor truck. Are you sure that the rear axle you're about to pick up has the 6-bolt hub flanges and came out of a 2WD Escalade or Denali?

And to answer your other question, no, a 9.25" front diff will not fit under a half-ton Avalanche, AFAIK.
sort of... 2010+ 2500hd axle pretty much bolts in. wouldnt call it a direct swap though :emotions122:
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