Transmission oil viscosity

Discussions related to motor & gear oils, greases, anti-freezes, etc.
fredpack
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Joined: Sat Feb 17, 2018 3:13 pm

Transmission oil viscosity

Post by fredpack » Sat Feb 17, 2018 3:48 pm

This is my first time on this forum so be gentle. I looked but didn't see the answers but I might have missed them so I might ask a question that has already been answered. I purchased a 1935 120 sedan from a man that owned it for 9 years. He drove it occasionally during the summer months but did almost no maintenance on it. I plan on using the car as a tour car this summer. The first thing that I do when i get a new (old) car like this is to go through all the mechanical areas. I've replaced the plugs, wires, points, condenser, tires, all 3 brake hoses, the rear rusted metal brake lines, rear shock bushings, checked the brake shoes, and changed the oil. I'm glad I found this forum because I didn't realize I needed to drop the oil pan but I will do that next. I hate to waste those 7 new quarts of 10W-40 but better to be sure than sorry. I have an original manual but it says to use Packard special oils from the dealer. Here are my questions.

1. I have drained the differential. What weight oil should I use? I have a gallon of 80-90W Nappa hypoid gear oil that I use in other vehicles. Is this acceptable?

2. What oil should I use in the transmission? Can I use the same 80W-90W? Even though the manual says Packard 160 weight with some kerosene added I'm sure the modern oils will be much better.

3. Does it make a difference what coolant I use? Is plain old green antifreeze acceptable?

4. Since I have to drain the 10W-40 out should I replace it with 10W-30?

5. Does this car have an oil filter. I can't find reference to it in the manual.

Thanks for any help you guys can give me. I have always wanted a Packard so you can imagine my anticipation to drive it this summer.

Dave Czirr
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Re: Transmission oil viscosity

Post by Dave Czirr » Sat Feb 17, 2018 4:43 pm

Welcome! And congratulations, a 1935 120, properly sorted out, should prove to be a delightful car.

You didn't give an area where you live and choice of lubricants can be somewhat temperature dependent. Assuming typical temperatures I'd use an SAE 85-140 extreme pressure (hypoid) gear oil in the differential. For the trans I'd use SAE 140 GL-1 simple mineral gear oil - best to avoid hypoid oil as some can be incompatible with yellow metals. Use ONLY thde old-fashioned green (IAT) anti- freeze.

Oil filters were optional equipment. Start with a clean engine and change regularly and you'll be fine.

Motor oil choice may depend on expected temperatures and engine condition. Once the engine is clean, you should feel comfortable using a multi-vis detergent oil. In warmer climates and with higher mileage engines many prefer the SAE 15-40 diesel/light truck oils like Shell Rotella T, Mobil also has an equivalent.

Don't forget the steering gear box (GL-1 gear oil), and a good thorough grease job on the chassis. You can use hydraulic jack oil in the front shocks.

I very strongly recommend getting a reprint owners manual and the shop manual!

fredpack
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Joined: Sat Feb 17, 2018 3:13 pm

Re: Transmission oil viscosity

Post by fredpack » Sat Feb 17, 2018 5:27 pm

Thanks. i forgot to mention that I live in Louisville KY. It can get pretty warm here in the summer. I can probably drain the 10W-40 into a clean container and reuse it. I also forgot to mention that I hit all the grease fittings so they are good to go. If it has the optional oil filter where is it located?

Dave Czirr
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Re: Transmission oil viscosity

Post by Dave Czirr » Sat Feb 17, 2018 5:38 pm

A canister with replaceable internal cartridge mounted to driver's side of the engine. I'm pretty sure the filter was offered as early as 1935 on the junior cars as an option or a dealer accessory, but I will check to be sure.

Yes, you can probably save and reuse that oil, though I'd do my next oil change sooner rather than later.

fredpack
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Re: Transmission oil viscosity

Post by fredpack » Sat Feb 17, 2018 6:02 pm

Something that I don't understand. What is the difference between a junior and a senior car? I've heard some people refer to the 120 as a "poor mans Packard." Does that mean it's a junior car?

Dave Czirr
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Re: Transmission oil viscosity

Post by Dave Czirr » Sat Feb 17, 2018 6:13 pm

It can be a long and complex discussion to cover thoroughly, but up u til 1935 Packard was exclusively a high-end luxury car. But as a recipe for surviving the depression they introduced the 120 in 1935 as a upper middle price car. The "senior" models in 1935 were th Eight, Super Eight, and Twelve, with prices at the high end many times a 120. And many body styles, wheelbases, and power plants, plus some bodies from the custom coachbuilders. By 1940 the Twelve was gone and the line between the junior and senior models became less distinct, even to the point of sharing bodies (though not engines).

Your 120 was a superbly engineered car, and a delightful, nimble car.

The best comprehensive history of Packard is the Automobile Quarterly book, often called the Kimes book after the editor though she wrote none of it herself. Its a monumental and comprehensive work, chapters by the acknowleged experts for each era. Long out of priint but still readily available.

fredpack
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Re: Transmission oil viscosity

Post by fredpack » Sun Feb 18, 2018 2:15 pm

I got the SAE 85-140 for the differential at Napa. Where can I buy SAE 140 GL-1 gear oil? The kids at Napa and the other local parts stores have no idea what I'm talking about. I've tried online and the only thing I can find is a 5 gallon bucket from Amazon for $50 plus shipping. I've tried all the hot rod sites, Summit, Jegs, Speedway, etc and Packard parts houses like Kanter and they don't carry it. I only need a quart or so for the transmission and some for the steering gear box.
I see lots of 75-140 GL-4. I've looked on other forums including old tractors and there are different opinions. Some say it is OK to use 140 GL4 but not to use 140 GL5 as it may harm yellow metals. Others say to use 85-90W gear oil. Some say to use EP and some say you don't need it. This is very confusing. I would like to find something that is locally available and in quart size if possible.

Dave Czirr
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Re: Transmission oil viscosity

Post by Dave Czirr » Sun Feb 18, 2018 3:17 pm

Either Restoration Supply or Restoration Specialties sells specialized lubricants in small quantities, one common brand is PennRite. The both have downloadable catalogs on their websites.

No, you don't NEED hypoid oil in your steering box, and it certainly would be OK if it doesn't attack yellow metals. But why take a needless chance. An SAE 85-90 gear oil would be ok as long as it doesn't have hypoid or extreme pressure additives.

GJBINSC
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Re: Transmission oil viscosity

Post by GJBINSC » Mon Feb 26, 2018 7:11 am

Dave: I found 140 GL4 at NAPA but was special order in qts. It does say Hypoid however, from a company called Stay Lube a CRC subsidiary. It does say good for Non-Ferrous metals, copper, bronze etc. Since Packard recommenced summer/winter change outs from 90w to 160w ( Whitmers Compound ) I thought running 140w year round in the South would be OK in gear box and differential. I also use 15/40 Rotella, been using that in my boat Diesels for years without issue. I carry 30 lbs+ on start up, and consistent 20 lbs with 160 dg engine at 35 mph which seems good to me. Your thoughts !

Dave Czirr
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Re: Transmission oil viscosity

Post by Dave Czirr » Mon Feb 26, 2018 7:25 am

Sounds like that gear oil should be OK for trans, differential, and steering gear box.

I use SAE15W-40 Rotella T in my '56 Caribbean because its very high mileage with clearances beginning to open up. You should check your owner's manual (reprints available) to see what Packard's recommendation on oil pressure was, what you're getting sounds a bit low to me, especially with such a heavy oil. With a nice tight engine you would want to use a lighter oil which gives faster and better flow and thus, heat removal.

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