Truck Repair: Transmission, gm rpo codes, google

Question
Van,  

I have an'89 Chevy pickup 4x4 1/2 ton.  I am having a hard time identifing my transmission type. It is a 5 speed manual with no identifying numbers.  I need to know what type of lubrication this transmission requires.  

Thanks


Answer
Hello Black,
In the glove compartment, there is a decal with about 100 three letter/digit codes. Those are called the RPO codes, which means regular production options. It is a list of everything that was installed on that particular vehicle at the factory.
Generally, the transmission codes will be in the "M"'s, like MD5, which is a manual 5 speed Getrack, or MH3, which is a five speed Borg Warner, etc.
Look your codes up, and let me know what they are, or just Google search for GM RPO codes. Then look all of your codes up.

The owners manual should tell what type oil it takes.


Van