Packard Forum Index » V-8 (1955-56)

The solenoids do sound as if they are OK now but unless you find a wire which may have shorted or something that might have commanded a large movement, those are the most likely cause of the back end raising up by itself. The normal tiny bit of leveling is generally over in a second and only moves the rear an inch or so at the most--not from level to fully raised.

The long bars have a fairly small movement and is primarily dependent on whether the level or wheel height changes. When the compensator moves, the short bars twist and apply an additional force to the rear load arms which either reinforces or opposes the load of the long bars to raise or lower the rear. The center point of long bar where the control switch link is located is essentially the neutral point and even if car is considerably out of level will only twist a fairly small amount.

There is an engineering SAE presentation given in 1955 on the bars and the basic operation if you would like to read a bit on the theory and development of the system.https://www.packardinfo.com/xoops/html/downloads/SAE_Torsion.pdf

UPDATE, UPDATE!! I finally got a chance to get back to the business at hand of stopping my manual valve leak and the raised rear end on my '56. Thanks to all for your gracious advice. PV8, that "Seal-All" is some good stuff along with ensuring the manual valve seal was seated properly with the aid of a deep socket. It appears the leak is history. As far as the jacked-up rear end, would you believe that when I got the tranny and the actuator finally in sync with each other, lower the car, and flipped the T/L switch under the dash to "on", the car leveled itself out? Is this a mystery??? Although when I pushed the "D" button, it didn't go into "Drive". However, when I pushed the "H" button, it went into "High". "Park", "Neutral", and "Reverse" all work. I'll try to figure out this weekend why I'm not getting "Drive" and even perhaps "Low" when I push their corresponding buttons.

My next project is to replace the seal where the drive shaft connects to the rear end. Does anyone have any suggestions on how to best tackle this job? I believe it's part number is 6484093. Do I also need to replace the oil slinger, gasket, and dust shield? Do I need a special tool to get the yoke (universal joint flange) off?

Hotrod..so glad to help and congrats on a good job. The TL issue was a recent one and I want to help others with what I learned. The members here are a fantastic bunch and they're always willing to share their wisdom.

As for the PB shifting issue, I think it is just a matter of adjustment. Mine did the same thing and I found that the mounting bolts had loosened. Once adjusted and tightened, the PBs were operational again.

I totally agree that we have a great bunch of very smart guys who are always willing to help another Packard owner in distress. I'm very proud to be apart of this group. Once again, that's good info about the mounting bolts; however, if they're tight, would I have to adjust the copper screw on the actuator motor just a tad bit? And if so, which direction would I turn? Standing by for news. (-:

Do you have any suggestions on replacing the drive shaft to rear end seal?

If the motor does not move the selector when pushing drive (or any range), a common problem has been inside the PB assembly on steering column -- broken contacts -- or the white plug at base of steering column has had one or more contact pins work loose.

If the shift motor moves but trans does not move car in D or you said possibly L, then very likely adjustment as bhappy said -- even with tight bolts. Manual valve being solidly centered in the detent is critical with the electric shift. D and L both need the low range servo when selected but none of the other ranges do. If adjustment is OK then loose inner lever giving some slop to valve, or other issues could be preventing proper operation.

The adjustment screw on actuator only controls hunting. If you push a button and hear more than one or occasionally two relay clicks when it reaches a gear then it might need adjusting because selector is not stopping quickly & is overshooting and has to reverse. If not hearing extra clicks then it is OK. If it is adjusted too tight, the extra strain on the motor could cause more problems--even to the point it can't overcome the occasional binding that sometimes occurs when on a slight incline or some other load is placed on the park pawl.

Hotrod -

Did you know that PackardInfo has an archive of shop manuals (and other factory literature) for many Packards? If you go to the "article" for the 1955-1956 Packard Service Manual, you'll see that it can be downloaded, by section (right click and choose "Save Target as...").

Be sure to download Section VI - Twin Ultramatic. For some reason, the table of contents are missing for these sections, but know that the factory issued additional pages to be added to the rear of each section in the '55 edition for equipment that changed for '56. The supplemental for this section includes the push button control and basic adjustments.

Additional technical information on the push button system can be found in the Auto-Lite Service Manual: 1956 Packard Transmission Control.

However, if you need to adjust the actuator relative to the manual valve, as HH56 noted, there was an article published, later, in a Studebaker Service Bulletin (SSB) that provides a procedure.

That and many other supplemental topics can be found in this site's Packard Service Index, and there's an installment specifically for 1955-56 (55th->56th Series) models. You'll find a wealth of topics on the TWIN ULTRAMATIC, with Push Button Control topics grouped together. Entries are hot-linked to the actual article (where available) in a PDF file. The bulletin you might wanna look at is SSB No. 338, p. 3; right click on the link and save it to your computer.

As for the "drive shaft to rear end seal", that is the rear axle pinion shaft seal. You should download the shop manual's Section XV - Rear Axle. Though the supplement deals mainly with overhaul of the new design rear axle, you may find some pointers regarding the pinion seal replacement on page 21.

Yet, the additional advice of a hands-on member is usually not too far away.