what pattern or letterin the vin numer will "decode" such information for me, i need to know if i have a 7 5/8 or 8 somthing inch rear end??? bc i have a bent axle after a curb saw my car and slid out infront of me lmao i know it is a bent axle becuase my spare last week was wobbley as hell

 

What year/model/engine/drivetrain config do you have? Please add that information to your signature so we can better help you.

There have been a few posts on axle identification. If you have a ZR2 (RPO code ZR2), then you will have the 8-1/2" rear diff. If not, then you'll have the 7-5/8" rear diff. The number of splines on the axle shaft really depends on the year and it seems that in the transition from 1st gen to 2nd gen that they intermixed the different # of splines... There should be a tag on the rear axle that will have some info on it.

To check what gear ratio you have, check your RPO codes.

If you have something else to drive, I would suggest you pull the axle and count the splines before ordering the replacement. It is possible that the dealership may be able to tell from the VIN number, but that would only be if it were new enough to still be in their database.

Your VIN consists of:

1. Country of Origin
2. Manufacturer
3. Make
4. GVWR/Brake System
5. Truck Line/Chassis Type
6. Series
7. Body Type
8. Engine Type
9. Check Digit
10. Model Year
11. Plant Location
12. Plant Sequence Number (positions 12-17)

Good luck!

 

I have a 4.3 1997 4 door lt regular NOT ZR2 (although i wish)I figure ifI am getting new tiresI should look into fixing that... wellI dont have the truck right now but I thinkI have the vin only on paper. just put on a2 inch body got 31's, truckbed coarted the underside andjasper trannyfront end etc. now i need to fix the axle and add my chrome the dif cover oh yeah sattelite radio and cd player oh yeah!!! S. forsuper U forutilitarian or utilisV for vegabond in the forest

 

A 28 spline at least.