I'm new here, and I'm at work so searching is limited.. but,

I have a 1997 GMC Jimmy SLT (which is pretty close cousin to the blazer) that has a damaged front differential. I think its missing a tooth or two due to an extreme situation. I just would like to know how to go about figuring out the ratio so I can replace it.

I've posted an exact carbon copy picture of my vehicle below.
http://www.autoseekandsell.com/userimages/Jimmy1.jpg

I'll spend some time searching the forum and visiting this thread. I only get 10 minutes each break
*COMBINING CONSECUTIVE POSTS*
http://www.s10forum.com/rpo/index.php

Please use the 'edit' function to add to an existing post is nobody has replied within 24 hours. Thanks.

 

n/m.

http://www.s10forum.com/rpo/index.php

 

The front ratio will be the same as the rear ratio. Inside your glove box you should see a long list of three character codes (RPO codes). If you search this website or the internet in general, you will be able to decipeher the codes and figure out what ratio you have.

 

look in the glovebox at the RPO codes.

GU2 2:73 ratio

GU4 3: 08 ratio

GU5 3:23 ratio

GU6 3:42 ratio

GT4 3:73 ratio

GT5 4:10 ratio

GQ1 Open Differential Rear Axle

G80 Positraction/Locking Rear Axle
I am gonna guess you have GU6 3:42 ratio