Restoration Qs...Shackle's

[d.j. moordigian]

This question is a " Fine Point question ". In the photo below, are high
dollar very early 28 double Ford script shackle's, they are also VERY worn.
For the past 3-4 years I have thought about HOW to repair shackle's. The
only way I can see is, weld them up with a TIG, then turn them between
centers, with a dog and a long boring bar. Anybody out there repaired
shackle's and how?

[d.j. moordigian]

Try this again.........

[Kevin in NJ]

A milling machine with a holding jig and a cutter that goes around was one thought.

Then I wondered about a deep hole saw for metal.

You will have issues with the weld shrinking the inside edge and causing them to bend inwards or at least that is my guess.

On the other hand, they do not have to be a perfect surface. They need to be smooth enough not to wear out the bushing too fast. So maybe weld them up and grind them close enough?

So these were my thoughts I had when looking at my original worn rears.

But then I bought an incomplete spring with a cruddy shackle. Turns out the shackle was a very good original. Later I picked up another good used original so I got lucky.

What about making a mold of the original script ends. Then use some later originals and JB weld to mold the script you need on good shackles?

[dave in australia]

These are highly important suspension parts, I would be very careful in welding any suspension part, as in getting are certified welder to do it, if your not one yourself.

[BILL WILLIAMSON]

Originally Posted by dave in australia

These are highly important suspension parts, I would be very careful in welding any suspension part, as in getting are certified welder to do it, if your not one yourself.

Dave,
I've known Dudley for 40+ years, he's an amazing, knowledgable, welder, machinest, and fabricator!! He can fix anything except a broken HEART. Bill W.

[gunmetal blue]

Sponsored Links (Register now to hide all advertisements)

Weld it up, then use a brigeport mill with a rotating table.

[Doug Clayton]

I bought the pair of double script shackles that were on ebay recently. My plan is exactly as pointed out by Kevin - make a silicone mold from the original then use the mold and JB weld to make new scripts on NOS shackles.

I don't like welding these parts because they are hardened steel and will be annealed by the welding process. Just my opinion!

[BRENT in 10-uh-C]

Originally Posted by Doug Clayton

I bought the pair of double script shackles that were on ebay recently. My plan is exactly as pointed out by Kevin - make a silicone mold from the original then use the mold and JB weld to make new scripts on NOS shackles.

I don't like welding these parts because they are hardened steel and will be annealed by the welding process. Just my opinion!

Doug, asking a metalurgy question, can a piece that has been heat-treated once ever be (re)heat-treated again? In this instance, after they have been annealed by the welding process, could they be heat treated again with any reliability?

.

[Doug Clayton]

Yes, they can. However, you must know the original material and heat treating process. The weld rod must be the same as the parent material (not always easy to find). Then in most cases you can repeat the original heat treating process.
The whole process will result in some distortion and minor changes in grain structure. For the Model A, I don't think these would be too serious. In the case of the shackles, I find the JB weld process much easier (and safer).

[Craig Lewis]

I did what's being described with the shackles on my coupe.
I built up the surface with a mig welder and machined them down in a lathe (using a rather precarious looking setup)...but it worked.
When finished I surface hardened them with a product called Casenite.
I usually like to show pictures, but I think those ones were lost in the "big crash".
Will keep looking and post if I find them.
If someone wants more details, ask, and I'll try to help.

[BRENT in 10-uh-C]

Originally Posted by Craig Lewis

I did what's being described with the shackles on my coupe.
I built up the surface with a mig welder and machined them down in a lathe (using a rather precarious looking setup)...but it worked.
When finished I surface hardened them with a product called Casenite.
I usually like to show pictures, but I think those ones were lost in the "big crash".
Will keep looking and post if I find them.
If someone wants more details, ask, and I'll try to help.

Yeah, I'll step up. I initially looked at a lathe and thought I realized that it wasn't gonna happen simply because even it I chucked up on the threaded area and tried to use a live center on the other end, the two issues I thought I was gonna have was the hole for the live center (grease fitting hole) was off-set on the spring hangers I wanted to repair, and even if I were to use a boring bar to make the cuts, I could not find enough room for my carriage to travel even with my tailstock completely extended. That is why I just turned around to my Bridgeport and thought a boring head on it would be better.


Ohh and Doug, I am truly disappointed to hear you would stoop so low as to use silicone to mould that script out of JB epoxy. It's not the use of the JB that has me disappointed, ...its that you haven't already written a program on your CNC mill where after a 'glob' of JB Weld had dried on the shackle you could machine the Ford script into the JB Weld!!

.

[d.j. moordigian]

Craig,

That's very much the way I saw it, right down to the Casenite!

Brent,
Go easy now.....I thought about that last night....but with silicon bronze weld
in the CNC mill!

Thanks to the Guy's that posted, especially Doug (you to Bill ), for the " fix ".

Dudley

[Bob C]

I don't know if all boring heads are the same but the one I have the head screws on to the shank. If you turn the boring bar around to cut the outside of something and run the mill in reverse as soon as you start the cut the head unscrews and falls on the floor, ask me how I know.

Bob

[Glenn C.]

IMHO if you intend on welding at all on those shackles, please request the services of help from your worst enemy to release the pressure from the spring spreader during installation. If you still have your heart in the endevor, at least wear safety goggles, face mask and heavy leather gloves.

[BRENT in 10-uh-C]

Originally Posted by Glenn C.

IMHO if you intend on welding at all on those shackles, please request the services of help from your worst enemy to release the pressure from the spring spreader during installation. If you still have your heart in the endevor, at least wear safety goggles, face mask and heavy leather gloves.

Glenn, with all due respect meant in my question, would this be something that you know would happen, --feel like could happen, ...or something that in your mind possibly has a chance of happening??

Why I am asking is I don't have first-hand experience either way however I would like to try, and if you have first-hand experience that this definitely will not work, I am very receptive to hearing what you are saying however surely you understand why I do not wish to 'not attempt' something that is indeed do-able solely because of someone's opinion that it might not work.



BTW, I was recently at another individual's shop who many here hold within very high regard in his abilities, and he has a stack of about 60 original shackles that he will be attempting to repair in the future. He & I briefly discussed how he was going to restore those and his method very much aligned with the "thinking" posted above. With a set of nice useable rear shackles bringing over $250 a set, and NOS rears bringing nearly double that amount, there is a valid reason to at least make an attempt to restore shackles as long as it can be done with favorable results.

.

.

[Craig Lewis]

Keep in mind the shackles are securely bolted together & supported by the end bar, even if they do crack. This takes most of the stress out of the equation although I'll certainly check my welded/rebuilt ones on a regular basis once the car is in everyday use.
My shop has been extremely busy which consumes my days, but I'll keep looking for the pictures of the lathe setup. I still have the support bar so maybe I can mockup the setup in my lathe again and give you guys something to flame

[plind]

Originally Posted by d.j. moordigian

Try this again.........

I missed thoose to on ebay . about a week ago....Did you by it.???

[v bogart]

Bob: I have solved that problem using a left-hand tool , You can buy one
or easily make one.

[Glenn C.]

Brent, sometime back in postings on the fordbarn....someone posted pictures of repo shackles that had fractured during installation. Granted original shackles should not be compared with original shackles as far as metakurgy is concerned, but I just have a hard time dealing with the fact of welding on any forged component, that even momentarily during installation could fracture, possibly ruining someones day. Possibly for ever. I am not a metalurgical engineer, but I am cautious about the possibility of upsetting the molecular structure of forged components by welding, and heat treatment to original specs. At the end of the day.....does a points car really mean that much ?

[Rowdy]

With what those brought it looks like I need to dig out the 2 or 3 well worn sets I have. Trying to remember where they are may be the bigger challange. Rod

[BRENT in 10-uh-C]

Originally Posted by Glenn C.

Brent, sometime back in postings on the fordbarn....someone posted pictures of repo shackles that had fractured during installation. Granted original shackles should not be compared with original shackles as far as metakurgy is concerned, but I just have a hard time dealing with the fact of welding on any forged component, that even momentarily during installation could fracture, possibly ruining someones day. Possibly for ever. I am not a metalurgical engineer, but I am cautious about the possibility of upsetting the molecular structure of forged components by welding, and heat treatment to original specs. At the end of the day.....does a points car really mean that much ?

Ok then, I now understand your position and your advice of caution. Thank you as I now feel better about what we are trying to accomplish. I also think the reference about the repro shackles was from Vince about 10 years ago. See if THIS jogs your memory regarding those broken shackles. At that time there were a few batches that had issues however that was corrected a long time ago much in part to Vince making others aware of this, ...but also note where this one broke in the pictures below. Like Doug mentioned above, the amount of heat that would be transferred into the piece during the build-up process would likely anneal or normalize the shaft making it soft, --not brittle like in the pictures below.

I would want to study the effects of the Casenite a bit more because I was under the impression it only case-hardened the surface area to resist abrasion or wear. When they were originally heat treated, maybe that is all the treating did too?? So, ..if the unit was originally forged, what affect did the heat treating after they were machined have on the forging? If none, what is the difference of using TIG weld to build up the shafts?

.

[Glenn C.]

Tig welding may be the best solution Brent. I wish an engineer with a metalurigical background would jump in here with his opinion.

[BRENT in 10-uh-C]

Originally Posted by Glenn C.

Tig welding may be the best solution Brent. I wish an engineer with a metalurigical background would jump in here with his opinion.

IMHO, someone pretty close in my mind already has above.

[RockHillWill]

Has not anyone considered using a hollow mill tool to turn the OD of the shackles and use a brass sleeve?

I saw a pair of these shackles done this way, but for the life of me I cannot remember who showed them to me.

I just acquired a hollow mill that was long enough to do the shackles from McMaster-Carr. I used it to cut thru the studs in a manner that saved both the rear hub and the drum, as I was looking for good steel drums.

I also use hollow mills to turn down the diameters on rebuilding shifting levers. I built a fixture that holds the shift lever in the tool holder and insert the hollow mill into the head stock.

It would seem that if the wear was not excessive, using a hollow mill and a thin sleeve would work as the load would be distributed evenly along the length of the shanks, and welding would not be required.

It has been my experience that Casonite, as applied by an amateur (me!), has little depth, and should only be used to provide a marginal increase in wear characteristic, and not be counted on to provide much in the way of additional strength-especially over welding!

[Roger V]

When I restored my first fine point project (a long time ago), I couldn't find good original rear shackles. I had our Tool Room (a Ford stamping plant) rework the excessive wear. I don't remember what they did welding-wise but I had full confidence with them. I do recall that they turned them in a four-jaw chuck with a boring bar. They came out great. On another note I had a driver Tudor with apparently the shoddy repro rear shackles of a couple of decades ago. One time I was checking the rear end lube and happened to notice one of the shackles was broken. Unlike Brent's it broke diagonal across the bar through the grease fitting hole. It was a testimonial to the strength of the removable cross bar(nut end) which carried the weight for who knows how long! Based on both of these situations I wouldn't be overly worried.

[Bick in New Zealand]

Sponsored Links (Register now to hide all advertisements)

I have some unmachined double script shackles cast in silicone bronze by the late Fred Gooding. Maybe this is the way to go, at least you know what you are dealing with from the start.

[Tom Wesenberg]

Originally Posted by Bick in New Zealand

I have some unmachined double script shackles cast in silicone bronze by the late Fred Gooding. Maybe this is the way to go, at least you know what you are dealing with from the start.

I wasn't aware of these.
How did they work out in the long run?

[RandyinUtah]

I welded up a set of originals and turned them between centers with the a boring bar. They have been in service over 20 years with no problems and no heat treatment.

[k24556]

OK, I don't know much at all about Model A's, but I can help in the metallurgy department. Just because this is a forged part does not mean it is not weldable. For steels, the amount of carbon in the steel dictates the potential for strength. The use of other alloy elements such as chromium, molybdenum, etc will dictate the DEPTH to which the strength can be achieved.

In the 1920's steels that were used for forged parts such as a shackle which would see both wear and heavy impact type loads were generally medium carbon, (0.45 to 0.6% carbon) and were heat treated with respect to the intended use. If the part was a wear part, like a gear, then it would be surface hardened and maybe case-carburized to increase the carbon content on the surface, and thus the hardness upon heat treating. A part like a shackle, would probably be quenched and tempered to try to get the hardening (strengthening) as deep into the part as possible.

So how do you tell what you have? a bench grinder will work. If you grind on a low carbon bar (or tube steel) you will get a long shower of sparks with lots of (what I will call bursts). If you have a medium carbon or high carbon steel, the shower of sparks will be shorter and wider (grind on a broken drill bit, for example), If the sparks are orange, you have cast iron.

So as a rule of thumb, weldability goes DOWN as the carbon content goes up. I would put a cutoff of 0.30 carbon max as my point where welding would not be performed. There are NO high carbon content weld rods to produce a high carbon content weld deposit. thus any weld metal will not have the same wear and strehgth properties as the original part.

My guess is that shackles started as 0.50 or 0.60 Carbon steel and were forged and heat treated to last. Welding them could pose a risk of cracking, but there is some skill and luck associated with welding such steels. You can preheat the item being welded, or the next weld layer can be used to temper the material hardened by the first weld layer. This tempering approach is falls on the LUCK side.

I'm about a week away from taking the springs off my A. Unless there is something mystical about the shape of the shackle, and I was not concerned about originality, I would probably make them from high strength steel, probably AISI 4140. I would make two studs threaded on both ends and two clevises. I would machine a radius in the diameter transition of the studs to avoid stress concentration.

Hope this helps