How to read the vehicle codes on chevy trucks to determine gear ratio of rear end

Question

How to read the vehicle codes on chevy trucks to determine gear ratio of rear end

Answer 1

can not read codes that way

Answer 2

You can:

- Take last 8 of your VIN and take to dealer and they can decipher.

- RPO code (found on door or glove box sticker) will start with G or J and call dealer to decipher.

- There is a 3 letter designation (found on case, but hard to find)

Answer 3

There is a tag on the differential cover housing get the number off of it and call your gm dealer...most glove box build sheet aren't going to give the rear end size.

Answer 4

Get in the glovebox and write down all the 3-character RPO codes begining with "G". Then go to www.rpocodes.com and read the definitions. For example, G80 is Posi. GU6 is 3.42s. GT4 is 3.73s. GT5 is 4.10s. GS6 is 4.56s. You get the idea. All the info you will need is on the site. Good luck.

Answer 5

depending in the year of your truck, it could have a tag on the cover bolt on the rearend that will tell you the ratio. if i knew wht year and motor you have in there,i may have been able to tell you .  all chevy 1/2 ton trucks came with three basic gearsets--3.42., 3.73. 4.10  the diesel were different and they could be 3.08 and 3.73 usually.... if you had a 4 speed box a straight 6 cylinder it should be 4.10. the v6's were mostly 3.73 for milage. check the glove box for a built sheet there will be a code in there and you can call any dealer to tell you whick gear it is.. hope this helps

Answer 6

Put you truck on a lift or jack up rear safely.  Mark driveshaft with grease pencil.  Have a friend rotate the wheel 1 revolution while you watch how many times the driveshaft turns.  Example, if you had 411 gears the driveshaft would turn just a little more than 4 times to one rotation of the tire. Hope this helps and be careful if you use this method.