None LSD differential oil

[MarkCan]

I’m about put my rear axle together in the coming days. All parts were either refurbished, refinished or replaced. Got all the cleanup done and unfinished surfaces coated with WD40 for now. I’ll most likely use a quart of gear oil just to wipe and soak all the components prior to assembly. I use the Valvoline 80W90 before and never had any issues. The best part is I can have it delivered to my door tomorrow. Now going to the full synthetic is almost 4 times the price. Do we really get that much more protection? I think I rather service the axle again in five years or so.
https://www.amazon.ca/Valvoline-High-Performance-80W90-3-78l/dp/B000CQ6L7I?th=1

[Bonnyboy]

Years ago when I refurbished my car it was suggested that I only use the Mercedes LSD specific oil in the rear end which I did.  I had 4 litres of the 80/90 for my Dodge on hand and was urged to use the Mercedes oil.  10 years and no problems so far.  have you contacted Mercedes?

The hardest part was arguing with the parts guy at the Mercedes dealership who insisted that I didn't have a LSD in my car as they were so rare.   It was the same oil they used on later LSD units.