Slew bearing oil recommendation Volvo EC390

I need to change the oil bath on the slew ring and Volvo gives no spec for it in the service manuals. They tell me 5 gallons but no viscosity. Dealer has the same book and is scratching his head.

I’m using, per Volvo spec, 85w-140 GL-5 in the swing reduction unit and final drives. Anybody think this is too heavy for the bearing? Should I go to 80w-90 or that too thin for the gear? Cost is the same either way. Anything else I might want use instead?

50T machine, bearing is about 48” diameter. We will almost never run it under 40°F but it will run in the summer at up to 100°F. Right now it is 85° here and I start a 2 acre pond next week.
Thanks.

I'm confused by your question. Are you asking about the lubricant that goes in the swing pinion tub or the swing reducer? As far as I know grease is what is used for the swing pinion and ring gears.

That’s what I was thinking John

John C. said:

I'm confused by your question. Are you asking about the lubricant that goes in the swing pinion tub or the swing reducer? As far as I know grease is what is used for the swing pinion and ring gears.

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I am asking about the oil bath for the swing gear and bearing. Unlike 99% of the machines on the market that use grease Volvo made this model with an oil bath slew gear and bearing.

shopguy said:

That’s what I was thinking John

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See my reply to John. This machine is an oil bath slew bearing. Rare thing indeed.

Good day CT
If the photo is the machine in question the normal lube was for EP90, if you prefer to use a heavy grade due to the tempreture I do not forsee a problem.
Kind regards
Uffex

Extra illustration.

uffex said:

Good day CT
If the photo is the machine in question the normal lube was for EP90, if you prefer to use a heavy grade due to the tempreture I do not forsee a problem.
Kind regards
Uffex
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Yes, that is the machine. Thanks for the input. I’m going to go with the heavier lube since I already have plenty in stock.