37 Pontiac Alternative Leaf Springs - todays vehicle comparison

All,

Would anyone know of a modern / todays vehicle that would have an "equivalent" rear leaf spring to replace my broken / worn 37's. I have a local wrecker that carries a few leaf springs and as long as they are approximate, they would work. $75-$120 each vs $400+ each is easier on my wallet.

The OEM's are apx 51" in length (center eye) with a girth / bend of apx 6-8" (from pin to apx level eye) and have 7 leafs... todays springs are made tougher so I could get away with a 4-5 leaf? correct?

Any comparison or advice greatly appreciated.

Your local spring shop should be able to rearch your springs and replace broken leaves for under $200 a pair.

This is including labor, drive the car in and drive it home fixed. I would get as close to OEM as possible but if the original thickness is not available you may have to settle for a smaller number of thicker leaves.

Looking at the pictures I don't know what is wrong with the old ones. It should be possible to clean them up, replace bushings and sliders, rearch and put them back on.

If you insist on doing it yourself buy a used spring with leaves of the same width and thickness and replace just the broken leaves. $75 is way too much for a used spring. You can get new ones for a few bucks more.

Your local spring shop should be able to rearch your springs and replace broken leaves for under $200 a pair.

This is including labor, drive the car in and drive it home fixed. I would get as close to OEM as possible but if the original thickness is not available you may have to settle for a smaller number of thicker leaves.

Looking at the pictures I don't know what is wrong with the old ones. It should be possible to clean them up, replace bushings and sliders, rearch and put them back on.

If you insist on doing it yourself buy a used spring with leaves of the same width and thickness and replace just the broken leaves. $75 is way too much for a used spring. You can get new ones for a few bucks more.

Rusty, took some advice and drove out of the comfort zone.. I was able to spray the leafs, thinking they were fused together being so neglected.. Turns out, torching the bolt off and patience, I was able to free them all apart and can restore them.

Appreciate the the advice after looking at pics.. Saved me a few $$

All, what liner should I use for anti squeak after painting? I heard many use slips of plastic, some use leather... Has anyone used a product called..DuraSurf™ thin gauge UHMW polyethylene.

http://youtu.be/47nR6Hq_i1Y

What did they have originally? Look at the end of the leaf, they might have a pocket for a brass or plastic slider even though the sliders are long gone.

The Durasurf looks like a good product. I would use the original sliders if it had any, if not use the Durasurf.

Look for wear marks in the spring where the end of the leaf on top gouged a groove. Smooth these marks out with a disc grinder and fine grit disc, while you are at it polish up the spring with the disc. For deep wear marks you might need to start with a coarser disc.

I have not heard of pre-war springs with "sliders" or any low friction insert between leaves, but then i don't know many vehicles other than my own. Your first couple of photos look more like the springs were wearing gaiters, perhaps of canvas or something similar. What are those scraps of woven material under the top plates? What are those flakes of metal in one of your pictures? From between leaves or around them? Just rust from the springs? My 1939 Studebaker had tin plate gaiters, with canvas inside around the springs to contain the grease. They were "sealed" at the ends and were supposed to be greased. A special fitting was required so they weren't greased often, if at all. They would take a lot of grease too. The net result is that the grease dries out.

The grease they used may have contained graphite, which is lower in the galvanic series than steel, so once the gaiter starts to break up (canvas is porous anyway) and the grease dries, moisture gets in and the springs corrode rapidly (galvanic corrosion), as yours have. Even if the original grease did not contain graphite, it did (and still does I believe) contain clay, which adsorbs moisture once the oils evaporate and causes corrosion in much the same way.

Leather is not low friction material and would wear out between leaves in no time. "Plastic" is also no good. You must have the rright product, if using one. Isn't a PTFE compound the usual insert to put between spring leaves? Is that what Durasurf is? Before proceeding, make sure your U-bolts and so on are long enough to contain the total height of springs plus inserts.

Are those rubber spring bushes? Steel outer and inner sleeves bonded onto the rubber? Pull them out of and into the spring eye using washers, pipe sleeve, lubricated bolt and so on. If they are, don't tighten the centre bolts through them until the car is on the ground. They work by the centre sleeve being held stationary in the shackle and the outer sleeve rotating with the spring eye by twisting the rubber. If the inner sleeve rotates, it will wear the bolt and itself - there is no lubrication. The shop manual should tell you about this anyway. The parts book may show washers, perhaps "anti-shake", at one or both ends of the inner steel sleeve to enhance the grip inside the mounting bracket when you tighten the bolt.

I just enlarged your pics for the first time. It appears your springs have been rebuilt or replaced in the past. The pointed end leaves are original, the square end leaves are replacements. The shortest leaf appears to have the end broken off unless the one on the other side is identical.

In addition to smoothing out any grooves or wear marks you should round off the ends of the springs to prevent them gouging each other. Just take the sharp edge off, you do not need to change the shape.

Have heard of people trying PTFE or Teflon in the past, it did not work, it was too soft and squished out. Nylon or some tougher plastic is better.