Rear axle cross compatibility.

[V327839]

I need to replace the rear axle of my 04 Suburban z71. I just saw that the rear axles are the same from 99-18? Did I read that post wrong? All I need is 3.73 gears and I’m good. I just need to know the year compatibility range before I make a couple hundred dollar mistake as I’ll be looking at a 02 Escalade axle soon. Thanks.

 

[Bigkevschopshop]

Finding the 3.73 gears will narrow you down on the years, I think only the z71 of the 00-06 had 3.73 gears.

The 3.42 and 3.08 rule the roost from I think 08 and up. The only exception was the suburban 2500 but its not compatible.
The main reason for the 3.42 and 3.08 option was the 6l80e has a deeper first gear and closer spread than the 4l60e.

Best of luck. Maybe try online salvage yards that are nation wide like LKQonline.com

 

[gooffeyguy]

My 2001 is an SLT with the 5.3l and 4l60 trans and has 3.73 gears

 

[Marky Dissod]

I need to replace the rear axle of my 04 Suburban Z71. I just saw that the rear axles are the same from 99-18? Did I read that post wrong?

Any ring & pinion from a GM 8.6" 10-bolt live axle can be installed in any other GM 8.6" 10-bolt live axle.
You read it right.

All I need is 3.73 and I’m good.

Unless you drive mostly or all highway miles, 4.10'd be even better.

 

[V327839]

I appreciate it. I’m not looking to change anything. It’s equipped with 3.73stock so I want to make sure whatever axle I find will bolt right in.
And it’s crazy that gm didn’t change the axle for that many years. I’m thankful as finding a replacement will be easy, but it’s crazy.

 

[Roilux]

Should you find an axle and don't have an RPO code to reference, I've found this online while looking for a rear end last year.

 

[strutaeng]

Well, they definitely did change them.

The GMT 900 based SUVs with 6.2 got an AXN RPO code axle which is like a hybrid of the 10 bolt and the 14 bolt semi float axle. I believe differential cover has 14 bolts and it's a 9.5" ring grar. The old 10 bolt 8.6" ring gear carried on as the standard axle.

For the K2XX vehicles, they introduced the 9.5/9.76" ring gear axle. I "believe" these are similar to the AXN, but not certain. Differential cover now has 12 bolts, so folks are calling this the "12 bolt." (Side note: the 10 bolt apparently was still being used on the V6 powered trucks; but we are talking SUVs here...) Obviously unrelated to the old 12 bolt from like the 70s...

Whether they are all interchange, I can't answer that. I think someone here has swapped a newer axle into...I think a GMT 900? I know I've seen a thread on that somewhere here.

 

[Fless]

My 2001 is an SLT with the 5.3l and 4l60 trans and has 3.73 gears

Same with my '04 LT 5.3, 4L60E and 3.73, RPO code GT4.

 

[Marky Dissod]

I’m not looking to change anything. It’s equipped with 3.73 OE. I want to make sure whatever axle I find will bolt right in.

Regardless of the hidden ring & pinion ratio, whatever 8.6" axle you find will bolt right in,
so long as it's from a '99-'18.
(Wouldn't want anything older, doubt 3.73 was available in '19 & '20 in an 8.6" axle.)
Otherwise I'd not have suggested it, and I'd've been swiftly corrected by now.
Again, for better metro / urban stop'n'go MpG, 4.10 is the ticket.
Not like I don't get that some prioritize highway MpG, for which 3.73 works better.

 

[V327839]

Thanks for all the help and info guys. I really really appreciate it. The one axle fell through but I’ve found two more to look at, both are standard 10 bolt with 3.73. Rust is my enemy right now and I’m hoping I can find a replacement that isn’t too bad off.