Gearbox Oil as lubrication for linear guides and ballscrews

Hello, i'm building a cnc router using ball screws and linear guides and i was wondering if i could use gearbox oil(75W90 / 80W90) or engine oil (5W40 / 10W40 / 15W40). I know that gearbox oil is pretty aggressive on orings and seals as the engine one, but maybe is not so aggressive on linear guides and ball screws. Gearbox oil could be the right choice because of it's high viscosity and stickiness but i'm unsure of the agressiveness.

Anyone has an idea about compatibility?

No eBay APP ID and/or Cert ID defined in Kunena configurationWhy would you want to? The price is nearly the same for a gallon of way oil versus a gallon of motor oil. Don't use used oil either. These are precision ball bearing parts and if you want them to last and be accurate use the correct fluids.

Many systems will use Mobil Vactra No2 but read through the parts you have and see what they recommend. Some of the DIY linear guides actually recommend grease and only need to be greased every xx linear feet of travel, which may be even cheaper than an oil system.

This is the common lube used:

VG 68

I thought about gearbox/engine oil because I have a lot of both, anyway, I have hiwin linear rails and ball screws. I'll read the datasheets for recommendations.

I use ATF oil while building the machines, then fill them with gearbox oil and forget about them. I am sure my customers will not oil them ever again, so at least they do have a head start due to stickiness mentioned above.

Hiwin carriages should come with grease nipples.
Way oil or hydraulic oil is the oil to use I think if not greasable.