How can I find out what rear end/gears/diff my truck is equiped with?

[yooformula]

03 Yukon with 5.3l 4wd. I am just curious what gears and standard equipment comes on this.

 

[Eagle]

3.73s are standard on the 03 4wd.

however it could have 4.10s too.

look at the RPO codes on the glovebox lid sticker (I actually took a picture of mine and brought it inside instead of try ing to write them all down)

I foret where I downloaded the pdf I have with all the 03 Tahoe options/specs (200mb or I'd upload it) but once you have the codes from the glovebox door, just go thru and find what they mean...

GT4 is a 3.73 and GT5 is a 4.10.

 

[05Yukon]

3.42 is standard. 3.73 is an option but a common option. GU6 is the code for the 3.42. G80 is the code for the rear locker.

 

[Eagle]

no, 3.42 is only standard on 2wd.
3.73 is the highest gear set in a 4wd.

 

[thumper_ehhhhh]

You can look up all your codes here
http://www.gm-trucks.com/rpo-code-lookup/
that way you will no for sure.

 

[WoldD90]

How do I find out what type of locker I have? I am assuming that it is either a Detroit or a TruTrack...

 

[yooformula]

thanks fellas!
G80- limited slip diff
Gt4 - 3.73 gears
G65 - LEVEL CONTROL MAN, SELF-ADJUSTING. not sure what this is but..
KG3 - 145amp alt. finally figured that out after trying 2 different belts and getting the wrong ones..lol

great little tool. I looked up every rpo code.

 

[Eagle]

G65 means you have Nivomat rear shocks...
and also have the ZW7 Smooth ride suspension.

IE if you want to change rear shocks, you have to go to a stiffer rear coil since the multi hundred dollar rear shocks actually do provide some of the weight carrying 'spring' in addition to simply dampening body motion.

It also means that your truck would level out after a few miles of driving if loaded down by a trailer or cargo.

It is NOT the z55 autoride with airshocks, compressor, etc...
but a simpler self contained shock working on the same idea.

Sadly it is still damn expensive to replace.

 

[yooformula]

THANK YOU! Great explanation!!! Does this suspension make lowering it more difficult?

 

[Eagle]

you know I haven't gotten that far... I've only had mine for less than 2 months.

no sensors to bypass like the z55 so it shouldn't be any different than a standard suspension, other than mandatory shock change for even a minor drop.

 

[redemn93]

after reading this i went and checked my codes. i have the GT4 G65 as well. no G80 though. why put an open diff in a 4wd truck? oh well.

but with the G65, i guess thats why i get more dip in the rear over speed bumps now after i just put in my bilsteins. should i go back to the stock shock until i can replace them? my stockers are still in the garage but they have 125k miles on them. what spring should i switch to if i go that route? i dont now if i want to do that though. it would be nice to have the auto leveling.

 

[rigo_jones]

**** yeah i got an LSD. its snowing here in denver and let me tell you my tahoe with lsd vs my suburban non lsd is a night and day difference. i didnt even use 4wd. cant wait to check all the options and see what alse i have.

 

[Eagle]

after reading this i went and checked my codes. i have the GT4 G65 as well. no G80 though. why put an open diff in a 4wd truck? oh well.

You are not alone...
most modern 4wds are actually only 2wd. 1 front & 1 rear.

 

[redemn93]

wait wait wait, i only have one wheel spinning up front also? time to call Eaton.