Leaf Springs Finish/Treatment

[Al 29Tudor]

I'm getting ready to replace the front axle so during the process I want to update the spring. I plan to check for excessive ware at the ends of each leaf, replace the shackle bushings and then re-finish, lube and re-assemble.
What is the recommend finish and lube for the assemble?
My first time doing spring maintenance so I'd appreciate your thoughts.
Thank you all,
Al

[Dollar Bill]

Prep springs with phosphoric acid to remove rust.

A light coat of extreme pressure (EP) on the underside of each leaf before assembly.

Paint with any good quality rattle can.

Consider investing in spring covers for longer service.

[Tom Wesenberg]

See reply #4, this works for me.

https://www.fordbarn.com/forum/showt...rease+graphite

[2manycars]

I use "slip plate" which can be bought in a quart can at any John Deere dealer, or some tractor supplies. Apply under each leaf except the main leaf, and when assembled, paint with your favorite chassis black.

[WHN]

If you have no experience with this type of spring, have someone take a look at it before you reassemble. Some old parts are just shoot, or close to being not serviceable. After all your work, you want the handling and ride to be right.

[Marshall V. Daut]

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Here are four photos of a typical Model A spring restoration, from rusting unlubricated leaves (as they almost always are upon disassembly), through grinding the ends with a taper, to applying Slip Plate on the undersides of the top 9 leaves (in a front spring). As already posted, the bottom leaf only gets painted on both sides.
Marshall

[Marshall V. Daut]

I'm adding two mores photos that show the tops of spring leaves before and after repair. The deep gouging is typical and is caused by the leaf above digging into an unlubricated lower leaf. Unless the gouges are really deep, they can be ground down. Teamed up with beveled edges, this is about as good as it gets for an 85 year-old spring.
Marshall

[Al 29Tudor]

Thank you guys.
This is just what I needed.

[AL in NY]

Has anyone tried adding plastic/nylon spring spacers between the ends of the leaf springs, similar to what was done on the 70's Mopar leaf springs?

[Marshall V. Daut]

Yes. In the 1990's I used the plastic leaf liners that had edges on the sides to keep the strips in place. They seemed to work well, but their number per spring added height to the spring, making it necessary to fabricate longer spring clamps. The liners seemed to add unwanted extra spring and bounce, so I went back to Slip Plate type of graphite coatings.
Don't bother messing with the thin Teflon rolls that you cut to length in strips and place between the leaves. It will drive you crazy trying to keep them in place while you put the spring together. They also tear easily and wear out too soon.
Marshall

[HammerSaw]

Tractor Supply Ez-Slide works great, just use gloves, it's hard to wash off.

[robert shreveport]

If you bought a new spring set from one of the top model A parts houses would you need to disassemble that and put slip plate between the springs before using?

[Pete]

Originally Posted by robert shreveport

If you bought a new spring set from one of the top model A parts houses would you need to disassemble that and put slip plate between the springs before using?

SlipPlate will not cure the faults of anything available from parts houses these days.

Here is an article that I published in a trade journal about 30 years ago.
It isn't the last word, just another way to do it if you want quality.

Reconditioning a model A spring.

First, inspect the top of all the leaves for grooving.
If grooved, grind and taper the tops of all the leaves
for the last 3 inches.
The number of leaves you use will depend on the final
weight of the car and the "ride" you want. On a typical
model A it is possible to get a 100 lb. per inch spring
rate which will give a very comfortable "touring ride".
Have the shocks disconnected when checking spring rates.
The easiest way to check spring rate is measure the height of a point on the front bumper. Apply a known weight to the front bumper such as a 200 lb. person. Measure the same point again. Say it went down 2 inches. You have roughly a 100 lb per inch spring rate on the front.
DO NOT USE GREASE BETWEEN THE LEAVES. It will only attract dirt and then you have grinding compound.
I Parkerize the leaves (optional) and then spray them all over with SlipPlate (trade name) which is a graphite spray or Moly Kote (trade name) which is a molybdenem disulfide base spray.
DO NOT PAINT ANY PART OF A SPRING.
(Unless you are restoring for judging)
The graphite or Moly spray will stop rust. Slip Plate can
be had at John Deere dealers. Moly Kote can be had at auto parts dealers.
I use 1/16 UHMW plastic between the leaves.This has similar characteristics to Teflon but about 1/3 the price. This is optional but really decreases friction and prolongs spring life.
After determining the final configuration of the spring
I wrap it with black electrical tape from the eyes to
the U bolts. This keeps dirt out. There are commercial
spring covers available also.
If you use a reversed eye main leaf, be sure the second
leaf is short enough that there is no way it can bottom
on the eye when at full compression.
Sometimes the original spring clips will not reach over
the spring after the UHMW is added.
It is a simple matter to fabricate ones that will.
The inside top of the cross member where the spring seats, usually has a radius.
BE SURE the top leaf of the spring has a radius to match.
A sharp corner on the spring leaf can cause a cracked
cross member.
I use moly filled Delrin shackle bushings because they
have almost no friction and they never wear out.
Anyone with a lathe can make these.
They should be drilled so they lube the ID and OD both.
They should drop in the spring eye with .003 to .005 clearance.
They should have the same clearance on the shackle pin.
By making them loose in the spring it DOUBLES the bearing area.
Commercial urethane bushings are also available.
While they last about as long as the Delrin, they tend to
squeak sometimes.

[Kevin in NJ]

Do you have working shocks?

If you make the spring springy then the car will not feel so good over 20MPH without properly functioning shocks.

[WHN]

I normally use new quality springs along with a new set of correct shocks, completely rebuilt front end. If you can afford the costs, the ride and handling are great. I have never taken a new spring apart before installing. Our 29 Sport Coupe was done 40 years ago, when other Model A owners drive it I usually hear how well it drives compared to theirs. Once you get it back together put it up in the air and grease it regularly. It's worth the cost to me to make sure everything is hit properly. You also get a good chance to check things out. At my age it is not as easy as it was to get underneath.

[redmodelt]

The springs we get from the place back east, yes you need to take apart, clean, prep and paint. I am going out on a limb and say I don't think the new springs come ready to install, at least I would want to make sure what is between the leafs. I make my own slip plate paint.

[WHN]

If your using leafs springs made with SAE 5160 steel, no grease, or potroleum products, they will effect the steel. Quality leaf springs made since the late 50's are made differently than the ones made in the 20's.

Depending on where you get you new spring. Taking it apart might be a good idea. It never hurts to check things out before installing. Measure twice, cut once.

[denniskliesen]

I just bought a new rear spring for my Tudor from Bert's and I asked Steve about the lube part and he said yes lube it. So I thought I'd use the dry graphite in the first picture and then I found a tube of the moly with graphite on another shelf in my garage. I think I'll use both.

[robert shreveport]

Bought my whole new leaf spring bundle from Snyders. Do you think I need to disassemble it and use the slip plate?

[denniskliesen]

Originally Posted by robert shreveport

Bought my whole new leaf spring bundle from Snyders. Do you think I need to disassemble it and use the slip plate?

Give them a call tomorrow and ask for Tom.