Transmission, differential and rear axel housing oil

I'm getting ready to replace the SAE 90 weight oil in the transmission, differential and rear axel housing before I use my Farmall A that's been sitting up for the past 12 years. A friend of mine sell Lucas Oil Products and suggested that i use some oil additives when I change the oil in these. Any suggestion from any of you regarding this idea?

I see no need for it, unless you have some issue that requires it's use.

They turn so slow plain old 90 wt works well. I have a friend in the oil business and he uses a 140 wt oil to reduce gear noise and slow leaks. Not sure how that would do in colder climates. I use some Lucas products in my truck.

I agree I see no need for it but, I never was a believer in oil additives until I seen what Lucas oil products do.

Lucas in the tranny will make it shift smoother. Probably not much help in the other areas.