How do you select the right lubricant for an equipment with missing/no lubricant specification?

Contact machine providor or agent , if not possible search similar machine in other places and apply the right lubricant

Is contacting the equipment manufacturer for help too easy an answer or is that not an option??

At first, probabbly the equipment needs no lubricant. You have to clearly identify which equipment needs lubrication and which are not. In some cases, other equipments do not need lubrication because it is already permanently lubricated.

lubricant selection depends on tempreture, speed and material of the parts to be lubricated.

If the part or machine is for food industry food grade lubricant is recommended.

Rassal

Sales engineer

By contacting machine provider

Or there is a common oil or lubricant for each part in machine

Gear box there is a common oil deoend on the load on the gear box

Bearing also now there is a common grease

the selection of lubricant depends upon the load, temperature and fricton.

when the load applied is too high then the friction takes place and temperature rises and the lubricant also heated.

there low quality lubricant will fail and then the lubricant select according to these conditions.

its viscosity maters in using conditions.

must have a machine catalog .in it having the oil specification. if the catalog is not available find rated speed,temperature ,nature of application etc, and choose apropriate lubricant. 

With missing required Lubricant specification, it will needs alot of studies to predict the totally right lubricant for your machine.

but selecting the most suitable lubricant, is better than using wrong one.

So, select a general purpose lubricant, according to the part you are going to lubricate.

for example, you shouldn't use engine oil instead of hydraulic oil for hudraulic application.

keep in mind, the analysis of the part you are going to lubricate. such as its motion type, speed, the load on it, and the temperature ...etc. then, try to decide which lubricant you will use.

Wish your predicted selection doesn't harm your equimpent or machine :)

By following the service and operation manuals 

and applyed all instructions if not ask agency of each equipment

The selection depends on temperature and load. It's better to know manufacturer recommendations.