Spring shackles differences

[36coupe]

I am a bit confused about the different types of spring shackles and bushings. The original one seem very rigid and hard to install. The aftermarket ones seem to be a slip fit and have lots of movement.
How much difference does the original metal bushings and the newer aftermarket bushings make whether they are oillite or nylon make?
I am thinking this question might be like asking what oil to use.

[19Fordy]

From my limited knowledge different bushings yield differing ride level of comfort and some report squeaking. I made some brass bushing many years ago and they have worked well. I haven't felt a difference in ride.
Of course, it's not a concourse car and my use of 20W50 doesn't effect the ride.

[Kube]

Originally Posted by 36coupe

I am a bit confused about the different types of spring shackles and bushings. The original one seem very rigid and hard to install. The aftermarket ones seem to be a slip fit and have lots of movement.
How much difference does the original metal bushings and the newer aftermarket bushings make whether they are oillite or nylon make?
I am thinking this question might be like asking what oil to use.

The authentic bushings when under "stress" offered a torsional resistance to the spring and as such aided in returning the spring to its natural level. This design was integral of proper handling of the vehicle.
Any replacement bushing that does not utilize a torsional resistance does little more than simply hold the spring in place.
On a vehicle with two transverse springs, it is critical to get the chassis / body back to its "natural" state as soon as practical to maintain optimum stability.

[ford38v8]

They will both do the job. The modern shackles have advantages that the original lack, but only the original will pass inspection on the Concourse. Mine are nylon, from Speedway, and afforded me an easy install, and further, an easy axle replacement while on a road trip. If your car is original otherwise, consider keeping it original with original shackles.

[Kube]

Originally Posted by ford38v8

They will both do the job. The modern shackles have advantages that the original lack, but only the original will pass inspection on the Concourse. Mine are nylon, from Speedway, and afforded me an easy install, and further, an easy axle replacement while on a road trip. If your car is original otherwise, consider keeping it original with original shackles.

Alan, please explain to me how modern bushings can offer any torsional resistance?
And, other than ease of installation, what advantage do the modern replacements offer that the authentic pins do not?

[ford38v8]

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Originally Posted by Kube

Alan, please explain to me how modern bushings can offer any torsional resistance?
And, other than ease of installation, what advantage do the modern replacements offer that the authentic pins do not?

Mike, I won't argue that point, because I doubt the significance of any minor torsional resistance with regard to shackles. The spring is going to flex the way a spring flexes whether the shackles are snug or not.

Ask me how I know about the advantage of "ease of installation" when it becomes necessary to do the job at the side of the road while traveling cross country.

[DavidG]

If you want to use the original type of stud, be aware that the only pre-WWII model year that Ford used rubber-filled studs was 1932. Starting with the '33s, the studs were packed with asbestos, which proved superior for the intended purpose (as Mike indicates above). Aftermarket studs found today inevitably are rubber-filled and tend to fail rapidly, especially after 70-80 years' worth of natural deterioration of the rubber. The evident supply of NOS '33+ studs is drying up, especially for the perch side and they have generally become expensive.

[19Fordy]

Thanks "Kube" for you explanation of torsional resistance of the OEM bushings.
I didn't know that. Be sure to include that in your book.

[philipswanson]

That's fine about torsional resistance but where are you going to find the original asbestos type bushings today? I had some repos from Carpenter but they were way oversize on the OD and when I tried to press one in, it simply folded. Some say hone spring ends with a brake hone but my Carpenter bushings were way too big on the OD. I went with Speedway shackles and even those were tough to install since they wanted to slip out because of misalignment with the axle housing arm bore. Two piece bushings present another problem. They slip out on the opposite end because of even a slight misalignment. After two weeks of struggling, I finally got them installed on my 40 wagon on the rear. Also I would recommend using the special sticky grease from Energy Suspension to eliminate squeeking.

[Kube]

Originally Posted by philipswanson

That's fine about torsional resistance but where are you going to find the original asbestos type bushings today? I had some repos from Carpenter but they were way oversize on the OD and when I tried to press one in, it simply folded. Some say hone spring ends with a brake hone but my Carpenter bushings were way too big on the OD. I went with Speedway shackles and even those were tough to install since they wanted to slip out because of misalignment with the axle housing arm bore. Two piece bushings present another problem. They slip out on the opposite end because of even a slight misalignment. After two weeks of struggling, I finally got them installed on my 40 wagon on the rear. Also I would recommend using the special sticky grease from Energy Suspension to eliminate squeeking.

Phil,
NOS are all over eBay and priced quite reasonably. I never have had an issue installing the bushings perhaps as I have the proper tools to do so.
The bushings are supposed to be oversize.
In fact, Ford called out for .0025" - .004" oversize.
I know a lot of guys grind down the shackle pin diameter to make it easier to install. Those same guys obviously don't understand why they (pins) were designed to be that size.

I did watch your thread in regard to installing that rear spring. In fact, as I recall, I had even offered a bit of advice.
I have replaced more pins and springs than I can recall. Yours? The pins (R&R) I'd allow an hour for - perhaps an hour and a half. The spring (R&R) another two hours.
Of course having the proper tools and skills no doubt helps.

[philipswanson]

Originally Posted by Kube

Phil,
NOS are all over eBay and priced quite reasonably.

Have not seen them for the '40 car. Also I have to wonder if 80 year old rubber is any good. You know tires only last for 10 years. I used a hard rubber formula but am inclined to go nylon or an oiled bronze next time, if there is a next time. Maybe on the front.

Phil Swanson

[19Fordy]

Yes, Phil I recall your battle of the bushings. Please post a photo of your 40 wagon so we all can share it's beauty. Crawl underneath and post a bushing photo also.

[philipswanson]

Originally Posted by 19Fordy

Yes, Phil I recall your battle of the bushings. Please post a photo of your 40 wagon so we all can share it's beauty. Crawl underneath and post a bushing photo also.

Again, I still don't have the slightest idea on how to post pictures.
Phil Swanson

[JSeery]

If you can email any photos you want posted I can help.

[JM 35 Sedan]

Some of the original shackle bushings on my 35's were a total disaster when it came time to rebuild the front and rear suspension. The pins/threaded studs were totally loose inside the metal casings. Most of the asbestos material between the pin/stud and metal casing was long gone. In some cases the pins had worn through the metal casings, and had actually started to wear into the supporting diameters of the wishbones. All of this convinced me that I was not going to use original shackle bolts on my rebuilds. I could care less what Henry used originally, I made up my mind I would come up with something better during reassembly, and I could also care less what the judges find on the show field.