The RPO code or whatever it is called... I need this to know my axle and gears info... I looked in the door jams and it's not there, in the console a little but it's not there...

Devastator X has helped me alot by saying he can find out my axle and such info, using math and things such as tire revoultions per minute... speed at 1500 RPM, and axle bolts.. Though its been 2 months... and I have not gotten it done... things have taken a turn for the worse with my dog passing away... can someone help me find my code sticker or do I have to do the work...

It is winter so it is hard to pull it out of the garage and get it on the street... I live in PA = Hills

-Thanks

 

RPO codes should have been on a sheet under the console lid...

Only other place i know would be the build sheet under the drivers seat.


But who knows, the car has been around for a while and could have had many changes by now!

Best bet is to just pop the cover off the diff, count the teeth on the pinion and crown and divide them together to get the ratio. Its probably wayyyy past due for an oil change anyways...

 

Here's how to determinne what ratio the rear is (jerk the diff cover and look). Numbers are stamped on the ring and pinion:

41 : 15 = 2.73
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73

JamesC

 

If you write down the VIN, you can go to a GM dealer service station and ask them to run it in a computer to spit out all the RPO codes for the car. I don't know the name of the system they use, but it is one of the old systems that looks like it is still DOS based. The printout will list each of the RPO codes and what they mean.

 

"Codes" are worthless.

All they tell you is what the car CAME WITH, not WHAT IT HAS NOW.

Even the "codes" off of the rear are worthless. All they tell you is what CAME IN THE HOUSING, and not WHAT'S IN IT NOW.

I have a 91 rear in my 83 car. It has an Eaton hi-perf (not a Gov-Lock, thank you) posi, Superior axles, and 3.73 gears. I know this because I installed them with my own hands. On the other hand, the codes say it has 3.23 gears and an Auburn.

What would happen if I tried to buy, let's say, speedo gears, based on the "codes"? First off, they wouldn't even find that rear in my year. Then it pretty much goes downhill from there.

Screw the codes. Pull the cover and look. If it really matters to you what's in there, it's the only way to know for sure. If you're not willing to do that, then it isn't important to you, because you don't REALLY need (or want) to know; and you're just wasting bandwidth.