Packard Forum Index » V-8 (1955-56)

I've just been browsing through some service counselors and was interested to read in Vol 30. No 5 the recommended method of adjusting the accelerator linkage for the twin ultramatic. I will check to make sure the measurements on my '56 Patrician line up correctly. However, one thing I noticed which confuses me is that after making these adjustments, it advises to proceed with the other adjustments as described in Service Buletin 56T-7. The service counselor diagram and also the description in the bulletin both indicate that the linkage is located in the centre hole, whereas the service manual clearly specifies the top hole. Which is correct and what are the implications of having the linkage in the top hole? Cheers, John

You have discovered some of the long standing conflicting/confusing information.

55s go in the top hole. 56s in the center hole. Moving the link further up makes the trans less sensitive to throttle opening. This is generally needed on 55s otherwise they kick down too easily,or kick down all the way to low instead of just to converter. The valve bodies on 56s were recalibrated and are generally happier in the center hole.

55 years and a lot of wear and diddling later, my experience is that the factory setting can only be used as a baseline. Start with that and then take the car for a goodly drive. If the shifts are smooth but positive, you are done. If the low-high shift lets the engine race or the direct shift groans you will need to move the adjustable link rearward on the throttle linkage till you get an acceptable result.
Moving that link rearward will give a later, and firmer shift. Better to err too far in that direction. Your clutches will thank you. Conversely, if you set it too far back, you will get kickdown when you don't want it.

Many of these cars have had multiple transmission changes and low-level blacksmithing done on the linkages, so I always adjust looking for shift quality.

Packard actually botched the instructions in one of the early 1955 service counselors, confusing "forward" and "backward", and then later correcting themselves. I thought the best explanation was their last, in the Studebaker-Packard Service Bulletin #340 of August 1958.

But regardless of whatever they said, I'd always give great weight to Ross' advice when it comes to Ultramatics.

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Yup, throttle linkage adjustment for the Ultras can be quite confusing - what with mis-prints (nobody is perfect), supplemental information, and running changes.

Thankfully, you'll find the bulletins and newsletter topics, from both Packard and Studebaker, all grouped together for the V8 cars in the Twin Ultramatic section of our Packard Service Index for 55th-56th Series.

Topics are similarly grouped in the Ultramatic section for 24th-54th Series and the Ultramatic section for 23rd Series. However, a few articles in those two sections are noted as "Linkage Adjustments..." because they cover not only the throttle, but selector, control valve, and other linkages

You almost have to print out each of the articles on adjustments (for the relevant Series) and study them in chronological order to get the full picture of what was going on, then. Yet, SSB No. 340 seems to sum it all up, and for all years/series - though the Twin Ultramatic is covered under the "Gear Start Type" heading.

Of course, Ross Miller's excellent advice picks up where the factory left off.

Thanks guys, that's very informative. When I got my car the linkage was in the top hole so based on what I now know, I'll change it to the centre hole and fiddle with the adjustments and check the shift pattern. It seemed OK before but maybe it hasn't been as good as it could be. Cheers, John

G'day Gents, well I tried to adjust it all up like the the service bulletin says and for my car, it's impossible! When adjusting the accelerator rod to the desired 3 3/8" to 3 1/2", the two pieces separated before we got there - there's not enough length in the threaded piece to allow it. The best I could do while still retaining some strength in the join between the two pieces is just over 3 3/4", so I locked it up at that. Given this, I wasn't sure whether I should worry about the tranny linkage being in the centre or top hole, so left it in the top for now. However, I did adjust it by applying slight forward pressure (towards radiator). Both levers appear to be in a similar position to the diagram, so hopefully this is good. Unfortunately I ran out of time for a road test but hope to tomorrow. Cheers, John

Does the carb throttle rod have a "V" bend in the middle of it? If so you need straighten the "V" out some to increase the length of the rod. I had to do the same on my car.

If we're talking about the adjustable accelerator linkage, no mine is straight. I've been thinking about this measurement issue and I'm now thinking, correct me if I'm wrong, that all that is doing is essentially setting the height of the accelerator pedal. Once done, then the more important step is setting the tranny shift linkage.

Three pic's are attached to show my setup. Pic 1 is how it was when I left it last night. Pic 2 shows the rod disassembled from the adjuster - you can see there is about 1/4" ahead of the lock nut, which is still in the assembled position. I've now relocated the tranny linkage to the centre hole (pic 3), adjusted the setting and taken the old girl for a short test run. All seemed to be working properly with perhaps slightly smoother shifts, and shifting into lockup from start at around 30 - 35 mph. It seems to be holding in lockup longer than before, which is probably what we want. However, it did groan (only once) after upshifting when going up a reasonably short but steep incline. As a result, I've followed Ross' advice and moved the lever back towards the firewall about 1/8". I haven't test driven the car since but will adjust this way again if the groan persists. Cheers, John

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You are correct, John; the first adjustment sets the height of the accelerator pedal.

This is not such a critical issue on the v8 cars in my experience. It is however on the s8 cars: if the pedal is not set pretty darn high off the floor the tranny will not kick down.

I don't know how relevant it is, but SB #340 shows an angle of about 30 degrees between the two parts of the linkage to which the rod to the carburetor attaches. JP's photos indicate 0 degrees - the two parts bolt in a straight line. I can't look at my car to see how it is.

Is the SB diagram an exaggeration?

Bernardi