4x4 rear axle in a rwd Tahoe?

[V-Code Tahoe]

Hello one upgrade I am pondering for my 2006 Tahoe is a gear swap. 3.23's paired witha 4.8 doesn't exactly result in breathtaking off the line performance, not to mention all the downshifts at highway speed. It is looking like an axle swap might me more economical way to get 3.73's in there than a gear swap, for me.

So here is my question- will a rear axle from a 4x4 tahoe/suburban drop right into my rwd tahoe?

Secondly, will a gmt900 axle drop in? Since they are newer there seems to be more of them around.

 

[Big Mama]

I think there are several ancillary items like drive shaft, brake set up, shock and spring placement. @swathdiver just did a gear swap. Maybe he can start you down the right path.

 

[Scottydoggs]

i would just buy a new set of gears in the ratio you want. add a limited slip diff too.

 

[Marky Dissod]

one upgrade I am IN DESPERATE NEED OF for my 2006 Tahoe is a gear swap.
3.23 paired with a 4.8L doesn't exactly result in ANYTHING RESEMBLING performance, not to mention all the downshifts at highway speed.
It is AN INDISPUTABLE FACT THAT an axle swap might be a more economical way to get
4.10
in there than a gear swap, for me.

So here is my question: will a rear axle from a 4x4 tahoe/suburban drop right into my rwd tahoe?

Secondly, will a gmt900 axle drop in? Since they are newer there seems to be more of them around.

The CAPS are what needed fixing.
So long as it's a 1500 Suburban, I don't see why any axle,
whether GMT400 in the 90s GMT800 in the naughts all the way to GMT900 in the tweens
would not fit with minimal alterations. If you find a cheap 3.73 axle, I guess I understand.
It would cost less than 4.10 with a limited slip.

3.73 is BARELY enough at best. I've a 5.3L 4WD with 3.73, and every time I step on it, another gray hair ...
The 4L60 will appreciate 4.10's extra help. You may very well begin driving conscientiously
to stay in 3rd-Locked or 4th-Locked as much as possible, and less shifts means it'll last longer.
I'd not be surprised if 4.10 did not cost you any MpGs, and your 4L60E would haul stuff better too.

IFF you are far more concerned with highway MpG, I understand 3.73.
But I can tell you, the amount of times I've required a 4Dn2 or a 3Dn2 on the highway
would be FAR less with 4.10 instead of with 3.73, what I have.

By the way, it should be obvious that a pcm tune would be needed for best results.
And don't forget that limited-slip diff!

 

[B-train]

I agree with @Marky Dissod. Go for the 4.10, your 4.8L will come alive with more rpm. And, I'm willing to bet you will get the same, if not better mpg as an overall average. Any rear axle from 2001 to 2013 should fit without much, if any, changes. I'd look for an avalanche axle that has 4.10. Plug and play

 

[Scottydoggs]

I agree with @Marky Dissod. Go for the 4.10, your 4.8L will come alive with more rpm. And, I'm willing to bet you will get the same, if not better mpg as an overall average. Any rear axle from 2001 to 2013 should fit without much, if any, changes. I'd look for an avalanche axle that has 4.10. Plug and play

i might be wrong, but most trucks that came with a 4.10 gear are leaf sprung and likely a 14 bolt full floater, 8 lug axle. they would be in a 2500 truck at min.

 

[B-train]

i might be wrong, but most trucks that came with a 4.10 gear are leaf sprung and likely a 14 bolt full floater, 8 lug axle. they would be in a 2500 truck at min.

I thought that you could get the 4.10 in some avalanche years. They used the same axle as a suburban. You could also get the 4.10 in 1999 and newer trucks 1/2 tons, but they are completely different mounting setups.

 

[strutaeng]

Hello one upgrade I am pondering for my 2006 Tahoe is a gear swap. 3.23's paired witha 4.8 doesn't exactly result in breathtaking off the line performance, not to mention all the downshifts at highway speed. It is looking like an axle swap might me more economical way to get 3.73's in there than a gear swap, for me.

So here is my question- will a rear axle from a 4x4 tahoe/suburban drop right into my rwd tahoe?

Secondly, will a gmt900 axle drop in? Since they are newer there seems to be more of them around.

Yes. There's no difference between 2wd and 4x4 axles. Does your axle have rear speed sensors? That would be the only consideration.

The GMT800 suburbans came standard with 3.73 (I believe some even had 4.10), so those are your ticket.

I think GMT900s are direct swaps as well, but the gearing may not be what you want because those came with the 6L80, which usually meant numerically lower gear ratio(?)

Truck axles are leaf spring suspension, so those are not a direct fit.

 

[swathdiver]

GMT800s have a rear track width of 66 inches and the GMT900s have a rear track width of 67 inches.

Lots of GMT800 SUVs have 3.73 and 4.10 gears. Many 2007-2008 GMT900 SUVs have 3.73s and rare for 4.10 gears.

I had 3.42 gears previously in my GMC Yukon XL. Switched to 3.73s and am loving it. Much bigger difference in acceleration and passing than expected. City mileage improved, have not really measured highway mileage changes, if any, yet.

4.8s like more gear, 3.73 or 4.10s. While the rpms will be higher than your 3.23s, the load on the engine will go down. Mine dropped about 5% across the board.

 

[V-Code Tahoe]

Thanks guys! And thanks Marky for the edit! This car is not my daily driver but more of a weekend and vacation cruiser so 3.73's should be about right. I am also running slightly smaller diameter tires, so it will be about equivalent to a 3.80 with the stock size tire. It sounds like the GMT900 are a little wider so I probably don't want to mess with that. So I guess I am looking for GT4 with G80 in an SUV or an Avalanche. Looking at car-part.com I see depending on year it asks if I have "active brake control (JL4)". My car does have that- not sure what that is exactly but would that relate to the speed sensors Strutaeng mentioned?

 

[Marky Dissod]

This car is not my daily driver but more of a weekend and vacation cruiser so 3.73 should be about right.

No, 4.10 will be better. 3.73 is BARELY adequate, at best.

I am also running slightly smaller diameter tires, so it will be about equivalent to a 3.80 with the stock size tire.

3.80 ain't 4.10. You've CLEARLY never driven a GM suv with a 6.0L, or a GM suv with 4.10.
Their 4L60Es last longer, and they get decent MpGs unless driven by leadfooted idjits.

It sounds like the GMT900 are a little wider so I probably don't want to mess with that.

0.5" wider on either side is not worth any concern. Open your options, don't close them.

... thanks Marky for the edit!

No thanks needed. For your sake, I hope you find 4.10 ...

 

[S33k3r]

Take a look at 2005 and 2006 Sierra Denalis. They will likely have the 4.10 gears and be AWD. That means they should have both axles you'll need. 2002, 2003, and 2004 Sierra Denalis should likely be avoided, as the rear axle will always be a Quadrasteer axle, unless someone swapped that axle out ahead of you. Also, if you have a street truck, get something with the G86. That's the limited slip differential, vs the G80 locker. Finally, make sure you check the pumpkin on anything you get. When people fail to maintain a G80, it will often grenade, taking out the axle and sometimes the truck too. I believe the Sierra Denalis came with 4.10s and G86 differentials.