Commonly, when need to buy some parts for replacement, you need a catalog to look up parts numbers. For example, you have a HW19710 gearbox to repair, and you have a catalog of HW19710 in hand. In this catalog, the part number of the main shaft is WG2203040009, so you inform your supplier of this number, and wait for its delivery?
You have to be sure that the numbers from nameplate is right, this is important to make others right. See below:
Separate different trucks with different slides or even documents if necessary, but the accurate chassis numbers
would be definite necessary.
The catalog will be also useful to you. Because for each model of engine, gearbox, cabin, and axle, 80% of parts will be the same regardless of improvement.
However, we believe a mixed method that includes catalog, your experience, and parts numbers provided by your customers, would be the best way.