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Right Oil for BN1 axle and gear box

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LuckyLuke

LuckyLuke

Senior Member
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What oil is best for the axle and gear box? My owners manual says W140 for axle, some say W90
 
Keoke, or Dave Russell, I got some LucasOil for the steering box, can that be used in the rear end of a BJ8?
 
dar100 said:
Keoke, or Dave Russell, I got some LucasOil for the steering box, can that be used in the rear end of a BJ8?
Click to expand...

Yes if you obtained the 80/140 Plus--Heavy Duty Gear Oil.---Keoke

You might be OK to add the 90W to the Hypoid?
 
LuckyLuke said:
What oil is best for the axle and gear box? My owners manual says W140 for axle, some say W90
Click to expand...

If your BN1 has the later hypoid gear axle (after C#221536 with 2.25" wide rear drums) any gear oil SAE rated GL-5 in 80W-90 should work in the axle. The sulfur found in GL-5 oils is a pressure resistant additive which helps protect the hypoid ring & pinion gears which are under a lot of sliding pressure. GL-4 rated oils do not have this high sulfur content. If your axle is the older spiral bevel type, it does not have as high sliding pressures & GL-4 oils should be OK.

For the transmission the factory originally recommended SAE-30 engine oil. Many folks run SAE 20W-50 engine oil in the transmission. A few prefer Red Line MT-90 in the transmission. These are NOT GL-5 rated high sulfur oils. GL-5 oils with high sulfur content are thought to degrade the brass/bronze components found in the transmission/OD's.

Because engine oil & gear oil are viscosity rated at different temperatures, 20w-50 engine oil & 80w-90 gear oil are actually fairly close to the same viscosities.

In reality, if you aren't putting a lot of hard miles on the car, any oils in any location would probably "get by".
D
 
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