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I own a 1941 110 that runs great except when trying to go to speeds over 50 mph. I understand the rear end ratio is 4.3/1 and this keeps the engine busy at 50+ mph.
Are there differential gears available to change the gearing ratio or is there a later rear assembly that can be retrofitted?

Hi Fred:

To give you a historical perspective, I trust you are aware there were no Interstate-style highways when your car was designed - normal driving speeds were so much lower than they are these days.

There were some places where you could go fast, really fast for a while (until a slower moving car or truck held everyone up, on those typical two-lane intercity highways).

True, you wont hurt that relatively modern "lower end" design of your car's motor by driving it at a steady 50 or even faster, but I agree - with the motor screaming away at the higher speeds, it isn't pleasant. And of course it is harder on everything - generator, water pump, etc. to be worked that hard (you'd have to drive a modern car well over 100 mph to get the same effect on its drive-line).

Reflecting the higher speeds as the roads improved during the 1930's, you will find some cars having two-speed rear axles or overdrives.

Elsewhere in this site you will find people suggesting that the smaller-engine Packards do not do well with a "higher" (numerically lower) rear axle ratio - not enough torque to give satisfactory performance. That is why you will find folks suggesting overdrives.

Packard did start offering overdrives as an option, as the thirties became the 1940's, but finding all the parts to convert your car to use that option would be unlikely. And even if you could convert, the Borg - Warner overdrives, while reliable in service when properly maintained, can be a "bar" to get set up properly when you are "starting from scratch".

My initial recommendation is you accept the limits of what your car is, enjoy it for what it is. It is a piece of history - trying to adopt it into a world that was inconceivable at the time it was engineered, will be expensive.

If you MUST drive faster for long periods - yes, an overdrive would be the answer.

But you are looking at a price range of around two grand for the unit, plus who knows what to hang it in your car between your existing transmission and your rear axle housing.

I personally recommend the HONE overdrive if you want a more pleasant-driving car at speed.

On level ground you will find driving your car at speed will be so much more pleasant. With the HONE overdrive's electric switch, you can easily "drop down" to direct drive to "pull" the grades you may encounter.

Can you post some photos of your car from various angles?

G'day fredfjfnc,
to PackardInfo and I invite you to include your '41 110 in the Packard Owner's Registry.

Overdrive was a popular "high performance" option by 1941 and many have added it after the fact. With it, you can drive nearly 70 at the same engine revs that are now giving you 50.

A Packard overdrive can not just be bolted onto the back of your existing trans as it is integral with the trans. Overdrive transmissions are not hard to come by however as a unit that will bolt right into your car was used through 1950. I think I have at least 2 on hand, and my buddy right up the road has a few more. There are some electrical controls that come with them and a control cable. You would need to have your driveshaft shortened unless you stumbled upon the right one. 110s were not often ordered with overdrive.

From memory I am thinking that the pumpkin in the 110s was smaller than the other cars. If it was a 120 you could drop in a pumpkin from say a 52 200 and have 3.54 or 3.9 gears.

Thank you for the response. Are you willing to sell one of the OD trans you have? If so let me know how to make personal contact.

Thank you for your historical background on the 41. It is a great car to drive and would like to expand its useage by increasing the top speed aspects.

Remember that the overdrive cars had a different ratio rear end so as to improve off the line performance with the overdrive making up for the loss at higher speeds. The non-everdrive rear end was something of a compromise so adding overdrive without changing the rear end will make a huge difference to the top end without changing the off the line at all.

PackardDon wrote:

"so adding overdrive without changing the rear end will make a huge difference to the top end without changing the off the line at all"
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Yes and no ! Depends on the Packard ! In the case of the pre-war six cyl. Packards, they simply didn't have enough torque to push their bodies thru the air at much over 75-80. No matter what the gear ratio, no way to get around the laws of physics.

Of course re-gearing thru installation of an overdrive is the way to go to improve utility of ANY pre-ear Packard.

The slightly larger 280 cu. in "120" series could probably get up to about 85, the so called "Standard Eight" ( 320 cu. in) was good for ninety, with a properly re-geared Super Eight ( 384 cu in) easily breaking 100.

Packard did a publicity stunt when the "Twin Six" was introduced for 1932 production - ( car supposedly bone stock ) ( my suspicion is they took out of parts inventory & installed the earlier 3.2 rear end gear set that they'd TRIED to promote on the earlier "Speedster" series.

The '32 Twin Six easily "beat a golf ball" - my recollection of what I read was that the golf ball was clocked at 122 mph - the Packard about 4 mph faster.

But don't expect that out of a Packard "six" or "120" no matter how you re-gear it! ( yes..I know..our "36" Packard 120's speedometer had numerals up to 120...! )

Point of all this - don't set folks up with the smaller-motor Packards to be disappointed!

All Packards were great cars for the money, they met or exceeded anything else in their respective price classes.

But again, do not expect a smaller-engine Packard can violate the laws of physics & deliver what the big ones could.

True, anything that will bring the engine rpm down at a given higher speed, will improve the performance; Packards were deliberately designed to give their maximum useable power (torque) at fairly low engine rpms. This holds true of ALL Packard motors of the pre-war era.

With highway speeds now up around 70 mph or even more, of course re-gearing ANY Packard is going to yield rich dividends in increased utility; much easier on everything that goes 'round' from the fan blades on back !

So if you gear ANY Packard so that the entire drive line is spinning at a engine speed "thinking" it was doing 40 mph, so that its road speed is, say 70 mph, it will be a far nicer, peppier car at that 70 mph than a stock-geared one would be. For the simple reason the "stock" gearing will have that Packard motor of ANY series spinning way faster than its max. power output.

Again, the problem is raw shaft axle power. Simply put, the bigger and more powerful the motor, the faster the car it is in can push thru road, tire, and air resistance.