New to the forum.

[2000 Yukon]

I have 2000 Yukon with G80 rear end. Rear end shot. Looking at junk yard for replacement. Found 03 z71 Tahoe with G80, how do I find out gear ratio? Thank you in advance.

 

[Tonyrodz]

I have 2000 Yukon with G80 rear end. Rear end shot. Looking at junk yard for replacement. Found 03 z71 Tahoe with G80, how do I find out gear ratio? Thank you in advance.

Look in the glove box for the rpos. If the rear is original to the donor truck it'll tell you the ratio. Could be 3.08, 3.73's etc.

 

[kbuskill]

I have 2000 Yukon with G80 rear end. Rear end shot. Looking at junk yard for replacement. Found 03 z71 Tahoe with G80, how do I find out gear ratio? Thank you in advance.

RPO sticker in glove box.

Should have a G?? number... something like this...
GT4 = 3.73 Ratio

GT5 = 4.10 Ratio

GU4 = 3.08 Ratio

GU6 = 3.42 Ratio

G80 = Positraction/locking differential

Or alternatively you can spin the driveshaft and count axle rotations.

 

[OR VietVet]

Welcome to the forum from Oregon.

RPO numbers. Sooooo much info there.

 

[Hobert]

If the sticker with the build codes is still on the glove compartment door, I found that the best way. My 2019 has a code of GU6 - REAR AXLE 3.42 RATIO.

 

[Joseph Garcia]

Welcome to the Forum from NH.

As folks stated above, your starting point is to review the RPO codes on the inside of your glove box cover. Just about all of the information that you will ever need to know about your truck is contained in those RPO codes.

Folks here are great, and they will freely share their knowledge, experiences, and perspectives.

 

[swathdiver]

I have 2000 Yukon with G80 rear end. Rear end shot. Looking at junk yard for replacement. Found 03 z71 Tahoe with G80, how do I find out gear ratio? Thank you in advance.

Welcome to the forum Joey! Post up some pics and if you don't mind, take some photos of the swap for the guys who come along after you needing to do the same thing.