Maintenance: RPO Code Database & Decoder

[Greg]

RPO Code PDF File

RPO Decoder

Straight-forward gear/axle RPO codes:
GQ1 -- AXLE REAR, STD RATIO
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)

HC4 -- AXLE REAR, 4.56 RATIO

 

[40oz to freedom]

Awesome, thanks for the RPO Decoder! My truck has the GU6 & G80 options!

 

[1993-Sierra-Z71]

im Surprised that the Z71 pkg. didn't include the G80 Positraction, at least it didn't in '93. Wish i had it.

 

[94Sierra4x4]

im Surprised that the Z71 pkg. didn't include the G80 Positraction, at least it didn't in '93. Wish i had it.

My '94 is not Z71, yet it has the G80 positrac option.. weird.

 

[1993-Sierra-Z71]

My '94 is not Z71, yet it has the G80 positrac option.. weird.

Total

 

[gmoutdoorsman]

So the GQ1 would be just a regular open diff?

 

[Joesgarage]

So the GQ1 would be just a regular open diff?

Yes
Unless It had a G80 code with it

 

[df2x4]

Not sure if this has been mentioned on this forum but here's a good site for decoding RPO codes. Also a great resource for determining what codes a vehicle has if the documentation is missing, just plug in a VIN number and it'll tell you.

http://www.compnine.com/

 

[Muskratt2]

So what ratio is a GQ1, GU2, G80?

 

[thunderstruck]

GU2 is a 2.73 ratio.


Sent from my Nintendo 64