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

I'm new to Packards. My 1940, 110 Business Coupe starts and runs smoothly. It has 115-118 lbs of compression in each cylinder. It does not have overdrive. At 55+ mph it sounds like it's screaming for me to back off. Is this normal?

Yes that's quite normal for a 1940. The standard rear end ratio in one of those cars is a 4.3, with 4.55 optional. Compare that with a 3.07 in an Ultramatic car from 1955. Neglecting the difference in tire size, your engine is running the same speed at 57 MPH as an Ultramatic car is at 80 MPH.

If anyone knows the tire OD's for both years, we can make a finer comparison.

Mikieb,

My first car was a 41 110 sedan and it was the same behavior as yours with the "3 on the tree" gears. You have strong compression (be happy).

I eventually located a transmission with an R9 overdrive on it and it changed everything. Normal highway "calm" RPM cruising was 65 mph with peaks up into the 80's for passing. Also, tremendously better nominal mileage. The output ratio of OD into the drive shaft was higher than 1!!! since the Packard engine stroke (all types of engines) was always designed for high torque.

There were several complete units at Hershey this year so you should be able to find an assembly. You'll also need the manual in/out lockout control, reverse lockout switch, kickdown switch and the main solenoid which attach to the OD unit or near the reverse shift linkage.

Post a "WANTED: R9 + Transmission for 1940 Junior Packard" ad in the forum and I'm sure you'll get plenty of responders.

I hope this is helpful.

If you have modern style tires on your pre-war car, that can cause the car to have a lower effective axle ratio, which you do not want. The tires the car was designed for were 6.50 or 7.00 X 16 bias ply tires which had an aspect ratio of around 90 to 95. That gave an overall diameter of 30 to 31 inches. Tire width does not affect engine revs per mile, but overall tire diameter does. Most modern tires are wider than the old style, but they have a lower "profile", with aspect ratios in the 60 to 75 range and overall diameters around 27 to 28 inches.

Adding an overdrive to pre-war cars not so equipped is a very good idea, and doing so will give you 4 speeds with a good road gear for speeds in the 45 to 75+ MPH range. The overdrive, when engaged, will reduce the engine speed by around 30% at any given road speed. In addition, you get a "passing gear" when you floor the accelerator in high gear. Besides all that, you retain the stock rear axle ratio, if you want to, which gives good performance and easy take offs with minimal gear shifting when driving around town in traffic. I've had several cars with overdrive, and I recommend it to anyone. It saves wear, saves fuel, and allows older cars (in good condition) to run easily at speeds over 50 MPH.

Overdrive was optional on many late pre-war Packards, and I think they called it "Aerodrive".
Information is available in the Literature Archive on this website.

Confirmed...it was termed Aerodrive...its been 50 years since I did that retrofit and TxGoat jarred my memory.

The kickdown switch is the device he described which cuts out the Aerodrive when you stomp on the accelerator and bottom it out...thus putting you back in third to pass at higher RPM/acceleration...then you release the accelerator and the solenoid pushes it back into overdrive and you slowly resume your depressed position on the accelerator to maintain "cruising altitude" steady speed.

I used to drive my 1940 110 without overdrive at highway speeds all the time without issues and yes, the rpm was up but sounded fine to me. It was a zippy, good handling car especially after I finally replaced the front shocks.

G'day Mikieb,
First post, so to PackardInfo.

I invite you to incLude your '40 110 in PackardInfo's Packard Vehicle Registry.

i would consider changing the rear, to like a 3.07 out of a chevy or ford, probably be cheaper in the end, Talk to a place that does drivelines, u wont have to keep spending to keep the O D working, and parts for the rear like axle seals U joints be alot cheaper than packard parts,and if the 3.07 isnt high enough u can go higher with a different ring pinion

I already have registered it. Thanks.

Thanks for all the info. I'm going to check on adding overdrive. My 52 Studebaker has O/D with a flathead six and works like you've described the Packard"s. My 50 Hudson flathead six has O/D that I've not yet been able to get working. I've got other cars to drive around, but, that Packard is such a beautiful car, and with cooler weather now, it's a pleasure to drive. It's very presentable, and could be competitive at most local shows, but, it's not a national competitor by any means, so, I was wanting to use it for local driving and maybe the FL Packard tour this coming spring.