RPOs not listed in GM's service manual?

Rocko973 · April 10, 2013

I noticed that there are some RPOs listed in my glove box that are not listed in my Factory Service Manual. To name a few, R9Z and SLM are not in the manual, but they are listed in my glove box. Can anyone tell me why, and whether there is an updated list somewhere that I can get or look up? I have 2003 Silverado 1500 HD, and I have GM's 2003 service manual.

Thanks!

Chris · April 10, 2013

Here is an RPO look up

http://www.gm-trucks.com/rpo-code-lookup/

R9Z CONTROL SALES ITEM NO.100

SLM SALES PROCESSING STOCK ORDERS

Z45 · April 10, 2013

Also, NOT all are really RPO's (Regular Production Option), they are components the line workers need to install dependent on the vehicle spec's. Also, not all RPO's mean the same thing on every model or for every year. You have to find the correct RPO list for the vehicle line such as trucks. For instance G80; in a GM truck or SUV its a Locking Rear Differential (never a limited slip). In a rwr or awd car its a G80 Limited Slip Differential. G80 is the most misunderstood option they have and some will fight over the meaning.

Rocko973 · April 10, 2013

Thank you for the RPO lookup link, chawkins6789.

Yes, I've seen the G80 RPO highly debated on forums. My service manual for my truck says that the G80 is a "positraction, limited slip". I thought those were two different things? So, I can see why it's misunderstood. I know for a fact that my truck is a Locking Differential, so I don't know why they'd add the term Limited Slip in the manual for my vehicle. Thanks for your respones!

MikeNH · April 10, 2013

Positraction is just a brand name for a limited slip diff. The G80 in the trucks is and always has been a locker. The manuals aren't always written clearly but the trucks have a locker, not a limited slip/posi.

Rocko973 · April 10, 2013

Positraction is just a brand name for a limited slip diff. The G80 in the trucks is and always has been a locker. The manuals aren't always written clearly but the trucks have a locker, not a limited slip/posi.

Then my GM Service Manual is wrong then... It's not a Limited Slip like it says there.... no wonder the confusion!

And I agree, the GM manuals are often not clear, as compared to my other non-GM manuals, but I can tell you one thing for sure is that I have learned quite a bit from you all on this forum, stuff that you'll never find in any service manual... Thanks!

ChevyTech77 · April 10, 2013

Where did you get this service manual from?

Rocko973 · April 10, 2013

Where did you get this service manual from?

I got the manuals from www.helminc.com. That's where a GM dealership told me to buy their manuals. Are there other sources?

Z45 · April 10, 2013

There is a limited slip differential available in some trucks (not most 1500, 2500, 3500 exc QS models) but its not rpo G80. Plus, all 2002-2005 Quadrasteer (QS) models used a Limited Slip but those were G86 and built by Dana. That may be were the manual confusion lies. Thats why they say manuals are designed for use by professionals who would hopefully be able to distinguish between the different types. Although I once po'd a GM service tech when I questioned why he had a bottle of the LSD additve and was about to add it to my trucks locker when had them change fluids. He would have if I would not spotted him walking back from the parts counter with it.