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"I'm pretty sure that the OD worked, but it would not kick down. Back to the drawing board. Pulled out the kickdown switch AGAIN. WD 40 got it to work, and it tested fine, though it took some pressure on the plunger. Put it back in. Tested the poles in relation to accelerator position and
NADA. The accelerator will not move the plunger far enough to break the OD relay circuit."

This is some troubleshooting I need to do...where is that switch located? My OD works fairly well but won't kickdown which makes for some very sluggish get-aways if I don't slow down enough at an intersection. A hassle to use the knob all the time.

Assuming you are also working on a 22-23 series here is a general illustration of that linkage showing the location of the kickdown switch. All years have a similar location for the switch but linkages vary considerably depending on year and accessories so the adjustment points may be very different.

The kickdown switch is mounted in the accelerator linkage transition bracket at the bottom edge of the firewall. Depending on which switch you have, some have double mounting nuts and a long thread where you can raise or lower the switch to assist in the plunger movement. Other switches are fixed in height and linkage is the only part that can be adjusted.

First step is make sure carpet is not bunched or anything caught under the pedal so it cannot make a full travel. If that part is OK check the shape of the pedal. On some pedals, if the foot pressure has always been applied more in the middle than the top the pedal can get bowed. In those cases the middle hits the carpet before the top can move the linkage all the way.

If the pedal is OK then it gets into the linkage. On some models there is only one adjustment point which can be in a rod on either side of the engine and separate length rods for different carbs are used. Many times the rods for whatever reason have been swapped with one from another engine and is of the wrong length which makes proper adjustment nearly impossible. On other models there are two adjustment points which over the years one might have been used more than the other so one is way out of adjustment with respect to the other.

When getting them back in relationship the first point is adjusted so the pedal can move full range and hit the switch to fully depress the plunger. Once that is done the second point is adjusted so the throttle plate is closed or open at full throttle depending on the respective positions of the pedal. It sometimes takes a bit of work between the two and of course still can depend on the proper length rod being installed.

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Thanks, Howard, that should be very helpful! I'm working on a series 23, btw.

The kickdown switch is located on firewall at the gas pedal linkage above the starter and below the temp sending unit. Remember, its upside down from most diagrams. Essentially, it deactivates the electrics that keep the overdrive working, so it drops back into direct drive. Then you just lift your foot off the gas and it goes back into overdrive. Its a blast!

Great! Who rebuilds them?

Project Update! The Overdrive is fully operational! I had the shop raise the brake pedal height, because my car has the "padded" gigantor accelerator option, and my foot would hit the accelerator when braking, a heart stopping moment each time. Also, I went to take a look at the under fender ducts, and the lug nuts were STUCK. My son and I bent a four way and they did not budge, so I had the shop take them off and put them back on.


The bad news is that a compression test shows that No. 3 cylinder has but 36 lbs of compression. I have looked into the cylinder and the piston is black towards the exhaust valve. Whether its a valve, piston, or something else, the head is going to have to come off. My car has chrome acorn nuts as head bolts. Were these a Packard option, or are they aftermarket? I'll need to know so I can replace them.


I plan to get the acorns off, then blast the studs with PB and let them soak for a while before lifting. I've got the good metal putty knives already for the effort. It looks to me like I have to remove the intake/exhaust manifold to get to that side of the head, so I'll soak those fasteners, too, beforehand. Any other tips/pitfalls to look out for?

Bright metal plated acorn cylinder head nuts were not standard or optional on your car. However they were still available as service parts for those prewar senior cars that had them or offered them so any dealer or person could order and install them.

No need to remove the intake/exhaust manifold assembly to remove the cylinder head. If you're going to do a valve grind, having the manifolds removed makes it a bit more convenient but still not necessary. One trick that's sometimes helpful to break the adhesion of the head to the gasket and block is to remove all the head bolts and washers if used but leave the spark plugs in place, and hit the starter motor; sometimes the piston compression will "pop" the head loose.

leave the spark plugs in place, and hit the starter motor; sometimes the piston compression will "pop" the head loose.

Great tip, holding onto this one. Thanks!

Well, don't get too enthused, I did say SOMETIMES.

How I got mine off.

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