Just bought a 544 and would value your recommendations for:
Engine oil? (Synthetic, which didn't exist back then, or regular?)
Gearbox oil?
Coolant?
Steering box lubricant?
Rear axle lubricant?
Gasoline? (My area is mandatory 10% ethanol.)
Thanks!

For my 1965 544 I use:

Accel 10-30W SF formula motor oil (available through Amazon) The "SF" formula oil contains the necessary Phosphorus and Zinc for the solid lifters/cam.

Per the recommendation of late Irv Gordon, I use 80-90 Gear oil in my M41 transmission with a Laycock Model J Overdrive.

Hypoid oil in the differential (non LSD) per owners manual.

Do not recommend any synthetic or synthetic blend lubricants as they seem to get by the seals - even the upgraded to neoprene ones.

I have been running Dextron ATF in my J type M41.

Engine oil: 30 wt or "10/30 or 10/40 with supplemental ZDDP additive"

Gearbox oil: GL1 mineral oil based

Coolant: I don't have a favorite

Steering box lubricant: GL4 or GL5

Rear axle lubricant: GL4 or GL5

Gasoline: Highest octane available and a lead substitute additive(not needed if cylinder head has replaced exhaust seats and valves)
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Doesn’t the diff and steering box require GL 5 for hypoid gears?

Thank you Eric. I find that I always obsess over 10-30 v 10-40. If the oil is too thick there'll be insufficient 'splash' lubrication. If it's too thin (like during really hot summer driving) then that's not too good either.

Any objective guidelines on viscosity selection based on location / season / ambient temperature?

Lastly, any brand preferences for the motor oil with ZDDP additive?

Many thanks.

KaiS
'67 B18-B

The diff does require hypoid gear oil, but the steering box does not.

Since Volvo made these cars, there have been improvements in hypoid gear oil.

When I started working on cars back in the 1970's, GL3 was relatively new and now there is GL4 and GL5 all them hypoid oils.

From what I understand, the basic hypoid oil is the same, but as the GL numbers get higher, there are more additives to better protect the internals.

As a side note, I've read that some of the additives in the GL series can be harmful to brass and bronze parts like those inside most manual transmissions, IE synchros and bushings, so you SHOULD NOT USE THEM IN TRANSMISSIONS THAT DON'T SPECIFICALLY CALL FOR THEM!!

I forgot to mention you didn't ask about brake fluid and you should only use DOT 4 brake fluid.


--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

what about limited slip dif ?

In almost every case, a special additive is used with the recommended hypoid gear oil when there is a limited slip.

planetman wrote-"In almost every case, a special additive is used with the recommended hypoid gear oil when there is a limited slip." When I installed a used LSD from a '76 265 into a '73 142 rear for my '69 144 I visited a local speed shop and bought containers of pre-mixed LSD gear oil. - Dave

straight 30? I wouldn't use 10w40 unless it was very cold. You need the viscosity for some oil to stay on the cam when not in use. I used older Shell Rimula X & Castrol Rx Super of CJ-4 Spec, 15w40, but drove it every day. These higher spec diesel oils also have additives that help with acid build up in your oil if you don't use PCV. They last A LOT longer too, with stock B18, B20, B230 I would use a double size filter, change the filter at 5000 and the oil at 10,000 miles. Even my racey engines, I would go 2500/5000.

I use Penn 5-30 semi synthetic. It has a high zinc content. I get it from Summit Racing.

Thank you! Will do.

How cold does it get where you are?

Won't get below freezing.