Pre-war (up to 1942) Lubricant

[KC Tom]

What lube should I use in transmission and tear end for a 1940 Lasalle

[Jay Friedman]

Do you have a shop manual for a 40 LaSalle?  If so, it should provide that information. 

In any case, in my 49 Cadillac I use 80/90 gear oil and both the  transmission and tear end. I think it must be the same for your car.

[KC Tom]

Thank you
I do have shop manual and will check

[tripwire]

KC Tom,
Pretty sure you want a gear oil that is safe for use with yellow metal.
Look for API GL-4 oil. Most part stores still stock this formula and it can be had in several viscosities, 75W90 or 80W90.

[TJ Hopland]

The whole GL-4 thing is pretty wacky, many of the products that say that also say GL-5 so its hard to tell if what you are going for or trying to avoid is or isn't in the stuff.  Its been a while since I looked for it and I think I still have a partial bottle but I think Napa told me they didn't have it but google said they did so I went in with the part number and they found it 'in the back'.  If I remember next time I'm in the garage I will see what brand or part number it is/was. 

Sidebar, has anyone seen that they now sell gear oil in a 'bag', think like the kids juice pouches.  Awesome invention.  Why did it take so long to invent that for oil?  You can squish and twist the bag in what ever direction or space you need to get it in the gear case the squeeze to make it come out.  Can't do that with a bottle most of the time. 

[dn010]

Sidebar, has anyone seen that they now sell gear oil in a 'bag', think like the kids juice pouches.  Awesome invention.  Why did it take so long to invent that for oil?  You can squish and twist the bag in what ever direction or space you need to get it in the gear case the squeeze to make it come out.  Can't do that with a bottle most of the time. 

I've been using the pouch of gear oil for a few years now, makes life so much easier as opposed to having to pump the oil in from a bottle on certain configurations. I wish I would have thought of it first!

[LaSalle5019]

I use 90w GL-1 in the transmission. It shifts better vs using hypoid oil in the transmission. The synchronizers have to squeeze the oil out of the grooves before getting the mating gear up to speed and the EP additives in hypoid oils resist that action so tends to require a bit higher shift efforts or longer shifts. The transmission does have some yellow metal components in it so you don't want to use Gl-5 hypoid oils as it tends to oxidize brass/copper. I spent 3 years in manual transmission development as an engineer at GM and have a bit of background in this area.

https://www.ebay.com/itm/376009933168?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338678874&toolid=20006&customid=4b91a26ac9391fa6ee33ca39b2c0d94d%7C%7C&gclid=4b91a26ac9391fa6ee33ca39b2c0d94d

For the rear axle I use Sta-Lube 85W90 Gl-4 Hypoid Oil.

https://www.amazon.com/CRC-Sta-Lube-SL24239-Multi-Purpose-Hypoid/dp/B000M8RYMC/ref=asc_df_B000M8RYMC?tag=bingshoppinga-20&linkCode=df0&hvadid=80401840125115&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=105926&hvtargid=pla-4584001418905927&psc=1