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

When there is no kickdown at all on a 51-54 there are three easy things to check first.

*make sure the spring loaded coupler on the carb pull rod has not seized. The linkage must overtravel to effect kickdown.

*The firewall bracket above the gas pedal has often collapsed back to touching the firewall as its rubber ferrules have perished. That cramps the geometry and makes it difficult to even get full throttle. I always just take an old shock bushing and wedge it between the firewall and the vertical bracket to make the cross shaft stand away from the firewall.

* make certain that the vertical push rod coming up from the pedal is adjusted long so that the mechanism down at the pedal is almost ready to go over center toward the rear of the car when at rest.

These items guarantee that you get full travel and a good non-sticky response at the pedal. I will try and take some pictures tomorrow. When these items are right kickdown is easily achieved and this whole discussion becomes pretty close to moot.

Quote:

56Clippers, Interesting idea, I'm going to check this as well when I recheck my settings. Even if it was out, say 1/4" longer, that would change the position of the arm on the throttle valve but the travel would still be the same. For things to work as intended, it's good to have them the way Packard designed them.

A project for after work!

Quote:

Some more good items to check! I just went and had a look....

1. The spring loaded linkage is not seized. How much should it be able to extend? It doesn't appear to be much more than about 3/8". If it's supposed to be more, maybe there is dirt or corrosion inside preventing it from "fully" extending??

2. My cross-shaft is loose where it is riveted to the bracket that bolts to the firewall. It pivots on the front rivet, but the back rivet is moving up and down. It goes from 1/2" away from the firewall to 1 1/2" away from the firewall, this probably isn't helping anything and should be tightened up. Maybe drill these out bigger and put larger rivets so it it solid???







3. My vertical push rod is not extended as far as it could be, and I know when I have the pedal to the floor it is all the way to the floor, which may be part of my issue as well. I may be fighting the carpet and underlay to get full travel.

Instructions for adjusting these linkages are on p. 27 of the service manual.

packardinfo.com/xoops/html/downloads/servicemanual5154/Ultramatic_VII.pdf

Obviously, if any adjustment is necessary, the throttle pressure adjustment (cross shaft adjuster) will also need re-set.

Hello All
Had an afternoon in the garage yesterday and things are looking brighter now.
I started by removing the Throttle Control Rod to check its dimensions. Big thanks to 56Clippers for publishing the right measures. It was 1/2" too long and i bended it back to the correct lenght. Re-installed the rod, keeping the throttle valve lever in the advance cheating position, which I had used before.
Next, I had suspected the Governor to be the culprit for the stoic DDC. Drained some quarts of ATF to avoid taking a bath. Then removed the Governor including the adapter. The Governor had the larger venthole and parts-# 434279, which is correct for the car. No binding or lash noticable and very clean. The Adapter has a small strainer which had some deposits which i removed carefully. Re-filled the transmission fluid, except for ca 1/2 quart which would not go in, as the converter meanwhile had drained into the pan.
Out for a testdrive and I started smiling. Due to plenty of Throttle Valve pre-opening (the cheating), the DDC closed at rather high speeds as expected (ca 40 mph at light load), but now it opened on the slightest throttle input. I could safely reduce the pre-opening of the throttle valve. Following this adjustment, the DDC will now close at earliest 25 mph on very light throttle and open at 15 mph at roll-out w/o throttle. The best is that the DDC still willingly opens on throttle input. I don't need to floor the accelerator, just quickly depress it about 2/3rd of pedal travel. No kick-down required.

Still not sure what it was that made all the difference. Most probably Throttle Control Rod length, may be a combination of factors. Could it be oil level? Before the overhaul, the transmission leaked a lot and the oil level was always on the low side. But at least, the DDC closed and opened intuitively. May be my Ultra works better with less ATF than the 12 quarts I poured in after the overhaul. Will probably do some more checks on this.

Cordial THANKS for all the knowledge and inspiration you all have spread during this discussion! Hope it will be helpful for you as well.

Well that's great news!!!

Sounds like you have your transmission tuned for sport mode! Correcting the control rod for the throttle valve certainly would have made a difference!

I need to get a few hours to work on mine and get it set up and operating properly.

Thanks for the update!

Quote:

Is that measurement for 26th series 28 25/32"? Mine currently measures 29" so just about 1/4" too long, that is, if that measurement is indeed 28 25/32".

Easier to read if you click on it to enlarge but it does say 23/32.

Quote:

I did enlarge it! Looked at it with my glasses off, and with them on, and still wasn't sure. I wish I was still young like you!

Thank you!

Sorry, no. They are both 29/32 as shown in SB-340.

That's part of the reason I made the montage image which combines everything into something a bit easier to see and understand.

packardinfo.com/xoops/html/downloads/SC/SB-340.pdf

Attach file:

---

  Screenshot 2024-09-24 191905.png (33.03 KB)


  extension linkage.png (116.85 KB)