Questions on '32 rear spring shackle install

[FourBangNCanuck]

I'm trying to install my new shackle bushings from macs on my '32 rear end.
They are too tight to slip right in so I threw the bushings in the freezer for a while to possibly get a slight shrink. I hit everything with some PB Blast then heated the axle eye a bit hoping it would all work. No go. I destroyed one of the new bushings beating it in an cooked all the rubber inside. So I'm going to order a few spares and take a Advil for my new headache.

So HOW does everyone do this?

[barnfind08]

You did it like everyone else does it. They also ruin a few so do not feel so bad.Here is what I have learned after doing a few on my cars. When the spring is rolled the middle is a smaller diameter so I use a bridgeport at a machine shop and open up the middle and dress it to 3/4" and they just slip in with a little locktite. All done no aspirin.

[barnfind08]

Related to your question I also run the axle housing to 3/4" The spring to 7/8" Sorry.

[Mike..Yorba Linda]

I turned mine down in my lathe for a snug fit...

[NealinCA]

I use a reamer in the perch and spring bore, then put the shackle cartridge in the lathe and emory it to 2-3 thousanths over. They press in without the use of aspirin then.

Neal

[DavidG]

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Too bad no one reproduces the K.R. Wilson too for this job. With one of them the shackle studs go in readily without having to alter the o.d. of the shackle stud or the i.d. of the spring. It strikes me that altering those dimensions will result in shackle rotation down the road.

[Mart]

I did a pair of perches last night.

I bought a job lot of 2nd hand reamers and they are always coming in useful. I ran a 3/4" reamer through the perches, didn't mod the bushes. I used a socket over the 3/8" square and pushed it in using the vise as a press. They were tight, though, I wouldn't have stood a chance without reaming them first. I think a steady push does better than a hammer blow. I mushroomed a few the first time I did the job, years ago. I have cheated in the past by filing the diameter down, but one of those started to wander after some miles so I wanted to try a better way.

Only 6 more to go!

David mentions the K R Wilson tool. Anyone have a picture of one?

Mart.

[Terry,OH]

There is a picture in the 1940 KRW tool catalog that is reprinted by Winfield tool. There is also a picture of a second hand press that is used on trucks. I used the principal of the truck press to make my own for cars for 3/4" only (RH below). If I was to redo it I would use a 3/4" fine thread shaft and have both the ends ( on the fixed end and the movable end ) changeable so it would do both the 3/4 and the 7/8 shackles. I always run a hand reamer, either 3/4 or 7/8, through the hole to clean it before pressing in new shackles. The spring side is usually no problem, some of the ends on the chassis side have holes that are too far out of shape to hold a new shackle. The hand reamer will expose this problem and the hole can be cleaned out and filled with Devcon plastic steel and the hand reamer will resize the hole.

[Kube]

It is imperative to be certain the hole is clean and true. It is also imperative that the pin be a press fit. Ford pins were in fact .0025" - .005" press.
Turning them down to make them easier to install defeats the purpose of replacing them. They must be able to withstand the torsoinal twist aplied by the spring each and every time it (the spring) osculates. If not, they simply do not do their job.
I can post a picture of the KRW tool if desired.
While assuring a straight alignment, it also supports both the inner threaded shaft and outer sleeve while pressing the shackle pin in to the perch.

[32phil]

I use a brake cylinder hone to clean up the axle housings, not too much, just enough to remove any burrs/rough spots. Same on the spring then some anti seize and press them in. They should press in tight if they go in too easy they will become very sloppy way too soon.

[Ed in Maine]

I messed up two sets of shackles before I finally got it right. Instead of pressing them in, I pulled them in by making a coupling between the bushing and a similarly threaded bolt. I took some nuts of the appropriate size and thread and welded them together to make the coupling. Then with a bunch of washers, a threaded bolt with the head cut off and a nut, I tightened the nut and gave the assembly a light tap with a hammer and the bushing jumped into the perch. Tighten the nut again and give it another tap with the hammer. I also put the bushings in my drill press before I started to remove any high spots. Ed

[NealinCA]

Reaming the perches does not remove any original material, just cleans up any rust, ridges, etc. I measured my new shackle cartridges. They were .006 oversize. I do not think they would press in with that much interference. I made a fixture that cups the end of the cartridge to press against. At .003 oversize, it took a lot of force to press them in. I destroyed a pair trying to press in at .006 oversize.
I assumed they made them that far oversize to compensate for worn perch bores...which mine have not been.

I agree that is you make them slide in with little effort, you will have problems.

Neal

[Mart]

Well after fitting the bushes to the front perches, which went well, I tackled the front spring. This is a 33, where the bush is 7/8" od. I reamed the spring holes with a 7/8" reamer. I offered the new bushes to the hole and guess what? It fell straight through! These are new original style shackle assemblies from Macs.

I only have metric calipers, and the bush measures a round 22mm (as if they are using some 22mm tube stock to make the bush). Now 22mm is a whole ,008" down on 7/8". So instead of being 3-6 though bigger than 7/8", they are 8 thou smaller.

I am 3000 miles away from Macs, so I had to come up with a fix. I used some shim material to make up the shortfall. Not ideal.

But that's not all.

I assembled up the perches to the axle and the spring to the perches and had another problem. The threads on the pins are not particularly well defined and the crappo nyloc nuts supplied with the pins strip before reaching a reasonable torque.

Absolute rubbish.

I have used some better quality nuts and have managed to get it assembled up ok.

But please be aware of the problems I have had, and if NOS bushes are available, use them before buying the ones from Macs.

Mart.

[russcc]

Check the post by Mike "Kube" Kubarth on Fordbarn, June 19, 2009. "Installing shackle pins correctly. In a nutshell; 1. There must be an interfernce fit of .004 - .006 oversize for the shackle assembly to work effectively. Grinding and reaming defeats the purpose. The proper tool mustr be used to remove & install. Displayed by Mike. You and turn adpaters up on the lathe to do the job, and use a ball joint press you can get for zip from Autozone or Advance Auto for lend. See Mike's photo of the whole rig. He will be happy to give you the dimensions of the adapters.

[Mart]

I disagree re the reaming.

A reamer will clean the rust and other debris out from the hole and get it back to factory size.

Reaming with a correctly sized reamer is a must.

Re the 7/8" front spring bushes from Macs. You can't skim or polish something to size that is too small already.

Mart.

[FourBangNCanuck]

Thanks everyone for all your input.
Looks like I'm not the only one who has felt with this.
So Macs is out of stock on their individual 3/4 shackle studs.
Anyone know where I can find them for sale? Or does anyone have some left overs I can buy??
Thanks!

[Henryat1140]

A slightly different way to solve the problem. . . .

I use the Pete and Jake's urethane bushed shackles. They are available through Posies.

Even though not original, I believe they are a better solution.

Rather than depending on NOS ones which may have dried out, or questionable quality repro ones, these do the job easily and with no fuss. Urethane bushings have been around long enough to prove themselves in suspension use. They hold the spring in very good alignment to the perch. They are about $40.00 for the front or rear, never need lubrication, they install without tools and can be painted black to 'almost' look like the stock shackles. Of course you would see the difference on close inspection, but unless you are being concours judged, they will pass all but the most detailed inspection. They are quiet.

I usually try to keep originality; 6V electric, mechanical brakes etc, but this is an exception and I feel the improvement in application, installation and use justifies the deviation from original. So am passing along a little different point of view or suggestion.

Others may disagree or argue for the original design and that's fine, but these work well for me.

[russcc]

Try Ray Helger at 401 685 4849. He likley has some.

[barnfind08]

I have the studs you want.