Packard Forum Index » V-8 (1955-56)

Hey everyone. I'm new to this forum and really need some help.
I have recently purchased a 56 Packard 400 which has been in the UK for almost 10 years and has never been on the road over here. This car has the self levelling suspension and the problem it has is that the front suspension sits right on the floor whilst the rear seems to sit in the correct position. The self levelling motor has been rebuilt and is working ok.
Any help would be much appreciated. Mitch

Hopefully you have the service manual in paper or downloaded. If so, have you verified when they put the leveler back in the car it was correct and transverse rods are in correctly. At neutral level point, the small levers connected to transverse rods at end of short torsion bars should point down or to just slightly toward center but more or less down. If that is not the case, then can you bring it level manually by removing the control link rod between compensator switch and the left main bar. When that is removed, there should be spring tension apparent on the switch when moving manually. Push it in one direction or the other to move the levers pointing down. Unless against a limit switch, after the delay leveler should start to move. If car can be leveled, then level it & Move the bracket clamped to the left main bar or the turnbuckle so you can replace the rod & keep the switch off. If that can't be done or car is not level when those are correct then we need to look elsewhere.

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Quote:G'day Mitch,
to Packardinfo, sorry I can't help with your query but there are knowledgeable, experienced and friendly Packard people here who will as you've already seen.

And a request of you, could you please include your '56 Four Hundred in the Packard Owner's Registry here, together with a pic, any known history and how you acquired it?

HH56, I tried your solution and it did not solve anything. Do you know of anything else it could be?. Could it possibly be weak torsion bars? I do have some spare ones to try but it looks a very difficult job to do without the proper tool. I've attached a pic of the front so you can see how low it sits.

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Assuming nothing is damaged or improperly assembled, it is possible the bars have "sagged" and can no longer support the weight. That much down does seem to be a bit extreme though. Has there been something added in front to make it extra heavy or removed in back? Are the A arm bushings too tight the arms can't move freely. That whole level system depends on friction free operation.

There is a tech bulletin outlining the basics with specs and suggestionshttps://www.packardinfo.com/xoops/html/downloads/STB/55T-1.pdf While your problem isn't the uneven side to side, all applies. Would be interested to know how many notches or lines are on the front load links you have.

If you do have short links, here's a link to Craig's websitehttp://www.1956packardpanther.com/adjLinks.html showing the link in place and his adjustable link solution--also how to change without the tool.

If it turns out you do need added length pieces, making your own might be the quickest option. There are commercially available links herehttp://www.thepackardlibrary.com/New%20Items.htm for the 56 but I notice they are currently out of stock. Don't know how soon or if they will have more.

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How about a picture of the rear of the car from the front of the rear fenderwell to the rear bumper? That would help us get an overall picture, so to speak.

Craig

I would be surprised if this were a case of weak torsion bars.

In the rare case that one of these torsion bars or its related suspension linkage breaks, the entire side of the frame would be in contact with the ground. As such, I can't see how ONLY "the front suspension sits right on the floor" while "the rear seems to sit in the correct position" would be the result of weak torsion bars. So, I don't think longer or even adjustable links will solve the problem at hand.

Mind you, this isn't like some torsion bar suspensions, where the bars run side-to-side and the front and rear suspensions are isolated from one and other. On the Packard system, the front and rear wheels are connected on each side, but each side is independent from the other - hence, the bulletin on using different lengths of links, to adjust level side-to-side.

As a result, the levelling system pivots the car, fore-to-aft, about a virtual center point (location of which depends on the vehicle's weight distribution, IIRC). With the entire system in good working order, properly lubricated, and with factory rear fender skirts installed, only about half of the rear tire, wheel, and cover will be visible. NEVER rely on the body side moldings as a visual reference to level; they're actually styled to run downhill, fore-to-aft (when the vehicle is level). The only true reference points on the body are the rocker panels - per the bulletin cited previously in this thread.

While the compensator motor is said to be running correctly, might there be a problem with the electro-mechanical level-sensing system? Wires or linkage simply, hooked up incorrectly would cause problems. Malfunction of the "black box" can put rear end up and front end down. Damage to the mechanicals should have been avoided as long as the limit switches were correctly wired and functioning properly.

Further inspection and information on the situation is needed to narrow the possibilities. A picture of the rear, if not the full side view would help.

BH, a good analysis and I fully agree with you. I VERY much doubt it's weakened torsion bars.

Not sure what the definition of weakened is but after 60 years it stands to reason things can get tired. I've seen sagging on much more modern cars. There have been several here lately with the same complaint of low height although don't believe to this extreme on one end.

Longer links have apparently corrected several of the lowered car issues lately--or at least don't recall any of those mentioning problems having said they didn't unless never tried. Believe Packard alluded to standard bars sometimes not able to cope with fully weighted cars even when new so they introduced the 9 degree extra twist bars.

Since one end is low, it was suggested he check the leveler adjustment as well as where the short bar levers were when leveler thought it was at neutral. Apparently those are satisfactory so that's why the suggestion of friction, damage, improper assy or excess or unbalanced weight was mentioned. If those all check out, then I don't think that leaves too much else to look at.

I'm not denying that the main torsion bars might have weakened over so much time and use.

For the sake of argument, let's assume that both bars ARE weak. However, since the main torsion bars are anchored only at their very ends (at the load arms), a reduction in preload (with all other things being equal) should simply cause the car to sit lower, overall - not just at one end. Longer links would raise overall riding height, on a side-by-side basis, then - not only one end of the car.

Also, unlike other vehicles with Automatic Level Control, the T-L compensator isn't activated based on riding height, but a differential, front-to-rear, in the twist of one of the main bars.

Let's assume, again for the sake of argument, that the front suspension is somehow bound-up on its pivots. I don't think the compensator would put the rear end at normal riding height, with the front end so low. If anything, I would think that the compensator would try to lower the rear - to level the car.

Therefore, I feel that something has been overlooked in the levelling system - could be electrical or mechanical in nature.

The owner needs to look further and tell us more.

Personally, I'd be curious to see how the vehicle sits with the compensator (leveller) removed from the equation. However, if compensator cannot be jumpered using the method outlined SC Vol. 29, No. 12 (for 56th Series) or equivalent method, the only other safe way, that I know of, to take any load off of auxiliary (compensator) bars is contained in STB 55T-12 - Step 5.