Re: 1956 Packard Levelizer - how long to level out?

Posted by HH56 On 2023/9/10 12:17:16

Specs say around 7 seconds for either direction.

If it still has the original control switch the time delay is done by a bimetal strip that is heated and takes about 7 seconds to bend far enough to make a contact and bring in a relay. Old switches can develop dirty or oxidized contacts from just sitting in an unused car or even in a brand new unit sitting in a box on the shelf. Either dirty contacts or burned out heaters can cause issues such as longer or inconsistent times or even a complete failure to bring in a relay to move the car in one or both directions.

In addition to issues with the control switch, a stuck 55 style limit switch or a broken wire going to one of the 56 style limit switches can also cause it to fail to move in one direction. 56 limit switches are somewhat prone to the broken wire issue due to vibration if the loom is pulled too tight or is unsupported when the long length of wiring going to the limit switch is bundled up. This is particularly troublesome in the switch nearest the driveshaft.

The control switch failure or erratic time issue can be solved by a reworked modern equivalent switch where the bimetal section has been removed and an electronic solid state time delay circuit or individual time delay relays are added. Those units have very consistent timing but depending on the switch and how it was converted, can be polarity specific.