Packard Forum Index » V-8 (1955-56)

Hi All,

I was wondering is it possible or has anyone put the 1956 Torsion level limit switches on a 1955 Packard with a 1956 compensator control box?

Any help would be greatly appreciated


Many thanks,
Mathew

Easiest would be to find and swap in the 56 complete assy. It should just drop in. Not sure what would really be gained though. The second version 55 limit switches seem to work OK. If it is a matter of waterproofing, modern silicone stuff would work wonders. That waterproofing was the main reason for the change of limit switches in 56 as was the 56 control box. Electrically the systems or functions are identical -- just a different layout to accommodate the waterproofing.

The 56 control box was a factory change or retrofit to 55s and consisted of the box and a short loom with different terminals to splice onto the old loom so the 56 box would connect. The limit switches stayed the same.

At a minimum to add newer limit switches to the 55 assy you would need to change to the 56 bottom housing to mount the switches. Also need the 56 lever and 56 2nd stage planetary carrier assy which is now also the cam to work the switches.

While I don't know the exact difference without comparing them, the manual also lists the ring gear being different as is the center support shaft assy which holds the gears and mounts the compensator to the frame. Those items may be height changes to accommodate the limit switches inside the bottom housing.

There are a few other small pieces with different numbers. None appear to be major pieces so the 55 equivalent would probably work. Again, would need to compare side to side and see what changed.

Here is a photo of the 56 lever, planetary carrier and bottom housing.

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My '55 Patrician has the '56 control box as Howard states and was on the car when I got it. After making sure everything got lubed and woke up after a 30 year nap, the system works fine.

Thank you Howard & Jim for your response. I agree when the system works its fantastic. I am now on my 3rd switch and hence the reason why I was contemplating going with the '56 setup but that looks like quite a bit of work. The reason for this switch failing was that 6 girls hopped into the back of the car (seats removed) at the same time and some how this managed to break the switch as it also bent the bracket holding the switch & solenoid. My guess is too many people getting into the car at once?

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Your passengers should not have caused any problems. Surely those girls can't weigh more than Packard spec'd the car was capable of carrying and remaining level -- 6 passengers and over 300 pounds of luggage in the trunk. Even if they do exceed, the suspension should have just shut off and instead of being level, the rear would be hanging low with no damage.

A couple of questions would be the condition of the transverse bars and the mounting bracket for the limit switch. If either is bent, I could see where that could cause a problem. With 3 switches it is unlikely they are now the issue but there was a design change to lengthen the switch actuation bar to prevent what sounds similar to the issue you describe. The bulletin 55T-2 mentions the new switch. It sounds like no other changes except lengthening the horizontal part of actuation bar to 2 1/16 inches to prevent over travel and bars striking and bending the bracket was made.

Wish I had a 55 assembly to photograph to compare with yours. Perhaps at some time something on yours was damaged and never repaired properly.

If anyone has good photos of the 55 compensator and limit switch assembly showing the areas where the bars activate the switch I would sure appreciate having a copy.

try my blog....start around page 18.

Thanks Hank. I found a couple but unfortunately none show the area of contact very well or anything to get a good reference from.

Correct me if wrong, but the switch doesn't appear to have any support other than the two buss bars. If the entire plate is torqued or the solenoids are different thickness or one of the mounting buss bars on the limit switch is bent in the slightest, would that not cause the actuator to be out of position and possibly lead to the failure Mat mentions?

I'm just guessing the actuator needs to be perfectly centered to the lever rotation center and the bars widest point needs to hit the actuator. Actually, it's been so long since I looked at one up close that I'm not 100 percent sure if it's the bar or the lever that hits the actuator.

I guess the question is how much error can be tolerated before the switch won't actuate or the bracket is hit and moved? How about the height of the switch bracket plate mounting above the main support. Is there anything there that could have been improperly assembled and is now too high or low. Anything you or anyone else could provide in information Mat could give his mechanic to ensure things are aligned properly am sure would be appreciated.

i do know that at one time my switch worked...then i put it on and tested and it wouldn't stop in one direction. i had to take the switch apart and adjust the contacts as one of the sides had gotten out of wack. i believe this was documented in my blog. then i resealed it and put it back together and wholla...it worked.

this is the only experience i have had go wrong with the switch itself. otherwise, I, like many here, rely on your vast knowledge. its been too long since i even looked at mine.

i don't remember if it is the bars or the lever that contacts the switch. but i do know that i mounted my solenoids backwards which i think caused the issue with my switch..IIRC. maybe his solenoids are backwards??

the only advise i have is to take the whole thing apart and rebuild exactly by the manual.

sorry i couldn't help more....its been awhile for me too.

Hank

I came across your PACKARD Forum conversation of a few years ago regarding the contact points of the compensator limit switch. I am looking for the same information. I inherited my dad's 55 Clipper Custom. Unfortunately, the switch needs to be mounted and I don't know how to do that; in particular, to what does the limit switch make contact? The car has only 32k miles on it, and I would like to get it in the road. I recognize that it is been a few years since your text string was posted, but would appreciate any help.
Bobby Rodd

The 55 limit switch mounts on the same bracket as the solenoids and is actually supported by the solenoids. That bracket in turn is mounted to the compensator assembly.

The limit switch has a movable arm on one end and when the motor rotates the output compensator lever assy, transverse bars attached to the output assy and connecting to the short bars on either side are moved into position so as to touch and push the limit switch arm to open the circuit. The right side bar touches one end of the arm and moves it inward. The left side bar touches and moves the other side of the arm. The mounting bracket can get bent over time so when you install the switch and bracket, check the alignment to make sure the transverse bars will meet the switch arm squarely and not slide over or under it.

As the title of this thread indicates a 56 limit switch on a 55, if that is what you have be advised that the two years are not interchangeable. The 56 limit switches are built into the compensator and actuated internally so needs the complete 56 compensator assy. Solenoids are also located differently and are not under the car in 56.

Here are a couple of 55 photos Stewart was kind enough to take and also a 55 schematic showing the complete circuit including contacts inside the switches which are not seen in the factory service manual diagram.

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