Spring Shackles

[BLB27]

How do spring shackles wear? Is the wear primarily on the bushing or does the shackle shaft wear also?

The reason I ask is: I had my rear axle unit rebuilt, and I inserted my original shackle into the perch on the wheel and found that there was some looseness. I am sure the rebuilder installed a new bushing in the perch so expected a tight fit.

I looked up new shackles in one catalog and found two options. One is forged and costs $145 per set and the other is $28 per set. Is the forged shackles that much better than the other?

[jiminbartow]

Both shaft and bushing will wear. A little wear is natural. I would think that the wear on yours is not enough to worry about since your T was so well taken care of over the years it was in active service. Jim Patrick

[Steve Jelf]

Yes, shackles will wear. I would rather wear out relatively cheap bushings than costly shackles, so I use bronze bushings. You can find them by size on the internet. As you have noted, new shackles don't come cheap. I would rather hunt down some good originals before spending the big bucks for new ones.


Front perch bushings(#3820) are ⁹⁄₁₆" ID and ¹¹⁄₁₆" OD, 1½" long.
Rear perch bushings (#3844) are ⁹⁄₁₆" ID and ¾" OD, 2" long.
Hand crank bushings (#3909) are OD 1", ID ¾", 2⅝" long,
Spindle arm bushings (#2714) are OD ¹¹⁄₁₆", and ID ⁹⁄₁₆", 1" long.
Parking brake cam bushings(#2559*) are 1⅛" long, OD ¹¹⁄₁₆", and ID ½".

*1909-1925.

I looked up new shackles in one catalog and found two options. One is forged and costs $145 per set and the other is $28 per set. Is the forged shackles that much better than the other?

Yes. The cheap ones are cheap for a reason. Better to find some good originals.
Most of the dealers have used parts not listed in their catalogues. You have to ask. I would start with Bob Bergstadt.

[jiminbartow]

Bruce can you send pictures of the spring and shackle bushings and shafts? Also, using a precision caliper (see attachment), provide measurements of the ID of the bushings and OD of the shafts. With that, perhaps members with more knowledge can determine whether or not they need to be changed. We need to know if the bushings and shafts are oblong. If oblong, provide measurements of the longest ID and OD. If shafts and bushings are perfectly round, they are probably not worn, for when they wear, they wear in the same place and become oblong. Jim Patrick

[Allan]

The cheap ones have the pins riveted into flat steel ends. They are known to fail In my opinion they are not fit for purpose and should never be offered for sale. A handy fellow could do a much better job making his own and welding the components together. Others may be able to post photos of failed ones shown before on this forum.

Allan from down under.

[Jim Eubanks]

Shackles wear out for lack of oil!

[Original Smith]

NOS shackles used to be easy to find, Not so much now, but they do show up on ebay. I prefer to use brass bushings, even though Ford used steel. We take better care of our cars now, and I'm sure we don't overlook lubrication as in the past.

[CudaMan]

For whatever reason, I have found that good OEM Ford rear shackles are harder to find than the fronts.

[BLB27]

Jim, Here are photos and measurements you asked for. The ID of the bushings is 0.562".

Are these reusable ?

[RajoRacer]

Just a FYI - those appear to be Model A - Model T's didn't use grease.

[Scott_Conger]

I would not automatically assume that an axle rebuilder replaced the perch bushings. That really should be verified, and for the effort you are putting into this car, while reusing old parts may be "OK", new parts with correct geometry will give better service. As the parts wear oblong, the bearing area decreases and pressure increases...oil will have less ability to stay put and do its job.

This advice is generic as I have done very little work on later cars and as such, think you should research Steve's advice on those perhaps being "A" shackles. I do not know, but Steve is a sharp guy.

[TRDxB2]

A minor problem with oil(or grease) is that many are water soluble, so attention to lubrication is needed. Silicone based products are less susceptible to water degradation. Curious - if good enough for a trailer why not a Model T - trim length to fit . Can we discuss functionality and not originality?

[Steve Jelf]

1923-1927 Ford shackle.

[BLB27]

I have verified that new bushings were installed in the rear wheel perch. Based on my caliper measurements of my shackles and amount of movement I get when they are inserted in perch and spring, I have decided to purchase new shackles.

Looking at Lang's and Snyder's catalogs, I have two choices: The forged shackles (like shown in Steve's photo) at about $160 per set or the U shaped $30 per set ones, which have the bolts pressed into the cap piece.

What is the experience with the cheap ones? Do the pressed in bolts come loose in the caps?

[TRDxB2]

I have some of the non-original pressed in bolts and intend to tack/finish weld them in and then they should be fine.