Interesting Tag

[4X4GMC1972]

I'm sure it was for identification purposes on the assembly line or the supplier to GM. Very common.

[Keith Seymore]

Originally Posted by 4X4GMC1972

I'm sure it was for identification purposes on the assembly line or the supplier to GM. Very common.

I agree.

It is the assembly plant "broadcast code", to help the line side operator choose the correct part.

There would be a different two letter (or three letter) code associated with each different part number permutation: so 2wd 1/2 ton would get one, 2wd 3/4 ton a different one, different one for 4wd, etc.

That way the operator needs only to walk over to the rack and select a "BD", rather than trying to remember part number 3986231 (vs trying to remember 3986232, 33, etc.).

They could be attached using the small bands you see here, or could be a paper tag stuck on the lug nut or an adhesive sticker stuck in some conspicuous place. You may even see paper tags wrapped on a part, like an ebrake cable or coil spring.

Hope that helps -

K