Packard Forum Index » Post-War (1946-54)

New member here! I am the sales manager for a large midwestern vehicle collection that recently acquired a Henney-bodied 1954 Packard ambulance. My owner drove the car for the first time today--it's equipped with a three-speed manual transmission. He said that when he stepped down on the gas at highway speed the car seems to "kick down" like an automatic transmission vehicle would. This is something kind of new to us, as the other 1950's era Packards we own are equipped with the Ultramatic transmission. Any information will be greatly appreciated! Thanks in advance!

A standard 3 speed will only have a 1:1 output in third and can do no more. Anything acting like a kickdown sounds like the car has an Overdrive and it may have been in overdrive mode which will give a 4th ratio.

Is there a round knob under the dash edge a few inches to the right of the steering column? If so, when the knob is pushed all the way in, at about 20-25 mph the OD will automatically go into prep mode and a brief release of the accelerator will let the solenoid engage so the 4th ratio is being used. This will drop engine RPM and noise significantly.

Anytime you are actually in OD and want more power such as when you want to pass a car a quick push of the accelerator to the floor will cause the OD to release and transmission goes back into a standard ratio. When the pass is complete, releasing the accelerator will let the overdrive engage again.

Pulling the knob out locks the OD out of operation so the transmission can no longer use it and straight 1:1 in 3rd is the highest ratio usable.

Sounds like the overdrive disabling itself for passing. The transmission proper will not shift itself.

In other words, what Howard said.

If you somehow don't have an overdrive then there is something really weird going on

G'day EDS417,

to PackardInfo.

I invite you to include the collections '54 Packard Henney Ambulance, plus "the other 1950's era Packards we own", in the Packard Vehicle Registry.

You didn’t say if it was a senior or a junior Henney. I don’t know for sure on the junior models but on the senior coaches, all had the overdrive transmission installed but not connected if not ordered. If ordered, they got the 4.7 ratio rear end but if not, there was a different ratio (4.1 I believe but not sure) that wasn’t nearly as zippy.

It is a junior series car. The information is greatly appreciated!

Folks, thanks for all of the great information here! My overdrive experience was limited to early 60's Chevrolets that had a handle to pull to engage. I figured this to be the case here but without the car present to check I decided to join up here and ask people who would likely know the answer. While our portfolio has over 40 Packards included all of our cars from this era have the Ultramatic so I was charting new ground here. Again, thanks!

Thanks for the invitation! I will enter all of our Packard vehicles (at this time there are 43 ranging from a 1910 to a 1958) as I get a chance! We have a portfolio of just over 420 at this time so Packard is well represented!

Howard, thanks for the information. It was exactly as you said. Our collective experience with overdrives was not on Packards and involved actively pulling the handle to engage rather than pulling the knob to lock it out. Again, thanks!

Quote:Looking forward to see them all included, in advance!