Packard Forum Index » Pre-War (1899-1942)

I just refilled my diff with 85W-140 EP. It replaced the smelly burned whale oil that has been in there for god knows how long.

I've done a lot of inquiries on this topic with oil companies and such.

The general reason many European makers specify 10w-40, or straight 40, for transmissions in the lack of EP.

Nissan specifies GL-4 which has less EP than GL-5. Your standard 85w-140 is GL-5 (gear lube).

However there is a military spec (ML2105 I think) that specifically requires GL-5 to be non-reactive toward bronze.

The modern EP is nowhere near the old stuff which was totally hazmat. I drained the trans in a 37 V-12 that was junked in 1956 and it had EP in it.

Things get more wierd because many GL-4 oils (if you can find them) are often just GL-5 with a different label.

Packard specifically warned that using heavy gear greases (250,600w) will damage the EP surfaces due to oil starvation. Many show cars have this stuff in them to reduce leaking and this is safe for trailers.

Bendix said no to EP in the overdrive.

A survey of later American cars shows EP sanctioned for manual transmissions from 1954 onward. Generally the reactive issue exists only at the high temperatures that occur on EP surfaces. Synchros don't get hot enough unless they are being speed shifted.

My experience is that 85w-140 produces notchier shifter feel in column shift Packards with better synchro action.

However in column shift Packards, I am now using a 50-50 Lubriplate mineral oil 140w, 85-140 GL-5 mix to please Bendix, produce authentic shifter feel, and provide the corrosion protection you get with a modern oil. This mix used to be called mild EP or GL-3.

Alot of the synchros in these old cars are shot and can't be speed shifted like when they were new. I don't know what the oil might have contributed to this result.

Avoid putting heavy greases into anything without first consulting factory literature.

Lubriplate 140w can be had through Restoration Supply and is a little pricey.

Some additional info on early EP lubricants:

The primary additive that was added to the early gear oils to give them the EP (extreme pressure) rating was sulfur. Because of the tooth geometry of the new hypoid gears used in the differentials the existing gear oils would not provide protection against the higher pressure gear tooth load that was present in the hypoid differential.

At the time sulfur or sulfur based compounds were used to give the lubricant a EP rating. One problem with sulfur or sulfur based compounds is when moisture is added the compounds tend to form sulfuric acid.

The acid that could be formed using a sulfur based oil would attack the lighted metals, brass, bronze, and aluminum.

If you've taken apart an old transmission or differential that used sulfur based oils you'll notice two things, a very distinct smell and a thick dark gooey sludge that covers everything. This smell and sludge is the remnants of the sulfur in the oil.

As stated in previous posts a modern GL-5 or GL-5 gear oil that meets MIL-L-2105 contains corrosion and EP additives that makes them suitable for hypoid and spiral bevel gears.

I've had good luck with a multigrade 85W-140W in a '32, 4 spd. syncro transmission, spiral bevel differential, and worm and sector steering box.

One trick that will help, machine the transmission and differential plug to accept a neodymium magnet that is nickle plated. The strong magnet will capture any fine particles that wear from the gears over time.

The same trick works equally well on crankcase plugs. If you use a neodymium magnet just make sure it's nickle plated to prevent corrosion.

A groove machined into the bore of either of the plugs will accept a snap ring to keep the magnet in place.

Regards,

Dave

Lucky guy, the 4-speed synchro trans offered only in 1932 is indeed very rare, only available for a very short time as they tooled up for the new 3-speed synchro. In fact in 45+ years of dabbling and talking with Packard owners I've only ever run across one other.

Owen,

I had it for a while before I even realized there was a lower 1st gear.

Because you have to pull the gear shift lever to the left and down against a spring and I'm sure there were a few that never realized this extra gear.

I never use the low low, at a slow idle in low low I can almost walk around the car.

Couple this with the high low end torque of the engine and it's no wonder these cars were turned into service station wreckers.

One comment on the '32 transmission, it has a very unusual sound. I've met people at shows that drove these cars when they were new and they told me it was called a "singing transmission". The transmission produces a sound in 1st and second that is hard to describe. Almost a musical note, not a gear whine.

Regards,

Dave