Re: '39 twelve squeeky rear springs

Posted by Owen_Dyneto On 2015/7/7 8:33:11

Since you say you serviced the spring eye bushings, I'm assuming the noise you hear is inter-leaf friction. An excellent lubricant choice for the flanged shackle bushings is a Dow-Corning silicone grease. Also the old-time standard lubricant for them was a product known as "RuGlide".

It would be helpful to know just what configuration of rear springs you currently have, I should remember what the 39 Twelves had as OEM but it escapes me.

Are your leaf springs "naked" or are they covered with metal gaiters which was Packard's prewar practice for many years and was used on the 1938 and prior Twelves, Super Eights and Eights. If the latter, the spring leaves were lubricated, wrapped in canvas, and then covered with metal gaiters and if this is the case, removal of the gaiters and re-lubing the leaves would be in order though it may well result in ruining the gaiters - forcing some heavy oil (SAE 50 motor oil or SAE 90 GL1 gear oil) in between the gaiter junctions might suffice. In the Bijur era the exess run-off entered the gaiters and maintained the lubrication. If they are "naked" leaf springs, do they have the antimony/tin/lead friction "buttons" at the end of the leaves? If so, they are probably worn out and I believe they are NLA. You might consider removing them if present and using Teflon interleaf liners as was a popular practice in the later years of leaf spring use. There were also special tools available that wedge the leaves apart and have an Alemite fitting to inject grease between the leaves - one sees these tools available not uncommonly at larger flea markets.