Technical Leaf Springs

1948 DeSoto Sedan

Rear leaf springs squeaking.
Any suggestions? Have used the rubber pads from Spring-Thing, sprayed between leafs with every grease know to man. Nothing has helped.
Replaced every rubber bushing, front and rear. No help. Replaced rear springs about 10 years ago, squeak started about year ago.

Jack

 

Turn up the radio!






Bones

 

Maybe the squeak is not from the springs?

 

Squirrel, where else should I look?

 

That is an old Ford trick. I worked with a lady that had an old Galaxie way back in the '70s. Her mill was so back that you could hear it rattling a block away. I said something and she said, "its a ford you just turn the radio up until you can't hear it."

She drove that bugger for another month until we could get a better mill for her old car.

Springs squeaking? The make these Teflon leave things that go between the leaves of the spring. Another thing that some of us do is take the spring down polish the hell out of it and round the ends of the leaves. That may be a more traditional approach to the problem.

Oh I meant to mention as @squirrel mentioned it may not be the spring. Sometimes a squeak is a cracked something.

 

Maybe the bolt going through the shackle bracket

 

If you can make it squeak by having someone push the car up and down, then you can get under there with a length of hose, use it like a stethoscope. Spring or shackle bushings and shock bushings are a place to start.

 

I had a terrible spring squeak on a 64 Merc once. I lubed the deck lid hinges and it went away.

 

Try this before rebuilding the springs:

Squirt penetrating lube like AreoKroil along each leaf on both sides. Use the plastic stinger resting right in the groove between each leaf. After soaking bounce the car by standing on the back bumper. Redo if necessary. Put some cardboard under the springs where it will drip.

Your car is old enough it should have zerk fittings for grease on the shackles and solid end. If they won’t take grease and are frozen, heat them with a heat shrink gun or even map gas for copper pipe sweating and the grease will soften an new grease pumped in.

 

I have always use RuGlyde, which is available at Napa for around $15 gal. It is (was)
typically used to mount tires, but is also a rubber/bushing lubricant. Simply put it into
a spray bottle and spray your leaf springs, shackles, whatever. Works great for me and
long lasting.

 

Thank Bob. That’s the product I’ve been looking for to squirt on rubber a arm bushings. They stock it at the NAPA near me for $20.

 

^^^^^^^^^
Mine wasn't! U-bolts had worked loose a little and axle was rolling up & down in the perches.
Who-duh-thunk-it!?
6sally6

 

A lot of things can cause spring/suspension squeaks.
One question, you said you used a number of lubes. Have you ever actually removed the springs taken the spring packs apart and cleaned up the individual leaves and dressed any wear areas and lubed them and put them back together?

 

Motorcycle chain lube works well for assembled springs. Sprays on as a thin liquid, penetrates, then sets up sticky...won't hurt rubber. When assembling springs, I use an open gear type lube between the leaves. It stays put, isn't affected by water and doesn't hurt rubber. There are several brands that do the same thing.

 

Jack the body up till the rear wheels are just off the ground, this will spread the leaves apart on each spring pack. Spray them down with lube of your choice. Be sure it gets all the way into to leaves. Lower it down and go for a drive, if the squeak is gone, plan on pulling the springs out for a total cleaning and deburring. Add Teflon type spring liner between each leaf and you will never hear from them again . https://www.speedwaymotors.com/shop/speedway-leaf-spring-liners~8193-10191-4713

 

Maybe a shock, had shocks do it before.

.

 

Another couple of ways to hunt for the source.

Metal rubbing on metal abrades the metal creating metal dust that becomes that powdery brown rust.

You can locate a lot of suspension and steering noises by feeling for them. To create a noise something has to vibrate the air. As somebody is bouncing the car, start feeling around with your non-dominant hand. I don't know exactly why, but your non-dominant hand is more sensitive than your dominant hand.

 

Fixed the radio, springs still squeak, just not as much .

 

That was probably easier then dissembling each leaf spring and fixing the problem. The next step up is to put an amp on he radio.

 

Paint the leafs with Dacromet [a controlled friction paint used on trailer springs]

 

Quick fix without disassembling the springs is lots of lube. But it's hard to get it into where is needs to be, between the leafs. What I've done is spread the leafs with a wedge. Mine is an end piece of an old leaf, just a few inches long and ground to a really slim taper. Drive it between leaf pairs. Then use a grease needle, like used on some ujoints on your grease gun to get some lube to the middle of the leaf. Repeat on each leaf pair.

Only works if the spring retainers are missing or can be spread enough to use the wedge. Usually pretty easy to do, just time consuming.

Side note, a lot of Mopars of those years came with the springs wrapped in a metal sleeve with lube holes in them. Good engineering and worth finding a set, IMfO.