Spring Hanger (Shackle) Bushing dimensions

[BRENT in 10-uh-C]

Does anyone have a print that shows the correct ID for installed Spring Hanger bushings?


We have broken our drill that we used to size new bushings after installing, and before I purchase another 14.5MM drill, I want to discuss sizing.


On the A-5465 print, it shows the finish size of the shank to be 0.565"-0.570". Using a 14.5MM drill as many vendors sell gives clearance of anywhere from less than a thou. of clearance up to just under 6 thou. when using an original (-or NORS) hanger.


The new repro hangers are averaging about 0.563" in shank size -which using a 14.5MM drill (0.5708") to size the bushing leaves about an 0.008" - 0.010" of clearance if the drill actually tracks straight however we all know there is usually a couple of thou. at minimum of run-out when drilling which potentially leaves as much as 12-15 thou. of clearance. I can buy reamers in 0.5650" or 0.5660" sizes that potentially give me 0.002 - 0.003 of clearance. Is that too tight, and/or is the 10+ thou. of clearance using a drill too much??


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[Dave1931Pickup]

Hi Brent
I don't have any dimensions for you but my preference would be to use a reamer not a drill bit. Reamers will follow the initial hole and open it up to the desired size. A drill bit will grab the wall of the hole and go in any direction it wants to wants to if your using a hand drill. A drill bit is less likely to do that if in a drill press but i still prefer a reamer in either a hand drill or a drill press. The drill bit has only two flutes while most reamers have five or more flutes which will provide a better surface and a rounder hole.
Just my opinion.

[Kurt in NJ]

I had a large rat tail file---- chucked in a drill--- it was just the correct size----

[Synchro909]

Reproduction shackles are VERY loose. Terrible quality!
For many decades, a drill has been plenty good enough for the shackles. From what Brent says, a 14.5 drill is plenty good enough. I bet Ford didn't fuss too much about shackle tolerances. IMO, a reamer is overkill.

[Res731]

I wonder if the tolerances really matter that much on a shackle. As soon as you drive it for a few hundred miles and with all the movement of the springs, doesn't it start wearing pretty quickly?

[Terry, NJ]

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I would love to see someone extrude a tubing (steel or brass) in the correct diameters for replacement bushings. The last ones I installed were small 14 (?) gauge plates that have been rolled into cylinders. These are subject to pounding and wear. Definitely not the best idea , especially when maintaining good caster angles (Front axle). I would be so easy to extrude a sized tubing all that would be needed is too part them off to length.
Terry

[Dave in MN]

I don't have any print info.

IMO: Too much clearance allows the grease to be easily pushed out and then you are back to metal on metal.

Brent,
I measured the re-production shackles in my bin and found the shank size .560".
The re-production bushings measure between .578" - .580" ID for the rear and between .583" - .587" ID for the front bushings.
This leaves .018" to .02" clearance for the rear and .023" to .027" for the front which is way too much.
I purchased a 14.5 millimeter reamer a few years ago and when I tried it on one of the new bushings it was a sloppy fit. The 14.5 reamer is .5708" or about .009" to .014" smaller than the bushing I.D. The expensive 14.5 millimeter reamer has never been used in the years I have owned it.

The last three shackle projects, I turned custom bushings from 4130 alloy steel round seamless bushing stock and reamed the I.D. with a .565" reamer chucked in the lathe. Using the reproduction shackles the resulting .005" clearance holds grease well over rough roads. For the rear bushings the stock was 7/8" OD with a .1.88" wall thickness resulting in .499 ID. For the front bushings the stock was 3/4" OD with .095" wall resulting in a .560" ID.

On my last road trip this winter, with .005" clearance, I greased every 2400 miles and probably did not need to yet. (Yes, the same trip when I parked my truck and trailer in your yard. Thanks again!)

When I drove Route 66 in 2013, I had new .560" shank shackles and the sloppy bushings with about .018" clearance on the rear and .025" clearance on the front and found myself greasing every 2- 3 days because the grease was being pushed out with the rough roads. You could actually hear the the metal to metal clash when going over a rough spot.

So from my own experience, .005" clearance works good. I use a "lighter" Moly grease for the chassis when on the road.

Hope this helps Brent.
Good Day!

[BRENT in 10-uh-C]

Originally Posted by Synchro909

Reproduction shackles are VERY loose. Terrible quality!

Are you referring to the original-looking repro shackles that were retooled and just came back on the market a few months ago

Originally Posted by Terry, NJ

I would love to see someone extrude a tubing (steel or brass) in the correct diameters for replacement bushings. The last ones I installed were small 14 (?) gauge plates that have been rolled into cylinders. These are subject to pounding and wear. Definitely not the best idea , especially when maintaining good caster angles (Front axle). I would be so easy to extrude a sized tubing all that would be needed is too part them off to length.
Terry

Great food for thought Terry.

Originally Posted by Dave in MN

IMO: Too much clearance allows the grease to be easily pushed out and then you are back to metal on metal.

Brent,
I measured the re-production shackles in my bin and found the shank size .560".
The re-production bushings measure between .578" - .580" ID for the rear and between .583" - .587" ID for the front bushings.
This leaves .018" to .02" clearance for the rear and .023" to .027" for the front which is way too much.
I purchased a 14.5 millimeter reamer a few years ago and when I tried it on one of the new bushings it was a sloppy fit. The 14.5 reamer is .5708" or about .009" to .014" smaller than the bushing I.D. The expensive 14.5 millimeter reamer has never been used in the years I have owned it.

The last three shackle projects, I turned custom bushings from 4130 alloy steel round seamless bushing stock and reamed the I.D. with a .565" reamer chucked in the lathe. Using the reproduction shackles the resulting .005" clearance holds grease well over rough roads. For the rear bushings the stock was 7/8" OD with a .1.88" wall thickness resulting in .499 ID. For the front bushings the stock was 3/4" OD with .095" wall resulting in a .560" ID.

On my last road trip this winter, with .005" clearance, I greased every 2400 miles and probably did not need to yet. (Yes, the same trip when I parked my truck and trailer in your yard. Thanks again!)

When I drove Route 66 in 2013, I had new .560" shank shackles and the sloppy bushings with about .018" clearance on the rear and .025" clearance on the front and found myself greasing every 2- 3 days because the grease was being pushed out with the rough roads.

So from my own experience, .005" clearance works good. I use a "lighter" Moly grease for the chassis when on the road.

Hope this helps Brent.
Good Day!

You are correct about retaining grease when there is too large of clearance. Additionally, the contact area on the shank of the shackle is much narrower (-like 1/2 the contact surface) which increases the pressure which likely never allows the grease to remain in that area. I guess eventually as the bushing wears to the shape of the shank, the contact area probably increases but at that point, it is probably too late.

Your thought about using 4130 likely means I now have another item that we will need to manufacture if we want to do the job correctly.

[Terry, NJ]

What about fusing some hard rubber to either the OD or ID. This is not as crazy as it may sound. I have seen prop shaft bearings that are made that way. These bearings had to deal with water, sand, dirt, misaligned struts and whatever. This style of bearing was used by the military on their boats. This bearing was made specifically by a company and used the company name (Damned if I can recall what it was) It was not a replacement for the OEM, It was an upgrade, (standard on military boats). It consisted of a small dia inner bronze bearing, an outer large dia. bearing with rubber (?) sandwiched between. 4130 seems a bit too much (Maybe not) and it's not a dissimilar metal (Steel against steel) Ideally, it should be aluminum bronze. Aluminum Bronze is one of the toughest metals I have ever machined.
Terry

[BRENT in 10-uh-C]

Originally Posted by Terry, NJ

Ideally, it should be aluminum bronze. Aluminum Bronze is one of the toughest metals I have ever machined.
Terry

If we are going to do that, I probably should look at using 841 Bronze material which is self lubricating. I have made bushings when I have restored shop equipment that have been in service for quite awhile. The biggest downfall I have with it is not machining it (-HSS does a great job) but my dislike is the amount of time it takes. If you take too heavy of a cut, it actually starts smoking as the impregnated oil is boiled out. Supposedly the stuff can even catch fire. About 0.010 a pass is all it likes from my experience.

[Terry, NJ]

Brent, what you're talking about is "Oilite" bronze, Boston Gear sells Oilite bushings. Why not contact them and get a price on 500 or a 1000. What you don't use you can sell. Actually, that wasn't what I was talking about. With the lube passages already in the shackle bolt, you don' need oilite. You need "tough"! That rolled up steel plate that they call a bearing/bushing is inadequate in so many ways! The Aluminum Bronze ( Cannon Bronze) is "Tough"! another choice would be the Manganese Bronze that they make propellers and rudders and other parts from. Maybe I'm just blowing smoke, but I really don't like what they're giving us and I'm thinking about having access to the ideal materials, Not pure unobtaininum. I get dreamy like that no and again!
Terry

[Joe K]

Cutless (trade mark) is the rubber bearing of propeller fame. The rubber is actually shaped with "ridges" and water is pulled into the interstice between the rubber and the shaft by the water's viscosity. The rubber compresses slightly in hydrodynamic pressure and the shaft actually rides on water.

It is a hydrodynamic bearing in its purest form - and doesn't even require oil.

But, for underwater applications (submerged in its lubricant) only.

Joe K

[Terry, NJ]

I'm straying away from automotive into marine, but we've all seen examples of where a solution from one sector becomes applicable to another. You're correct about "Cutless" bearings. I just couldn't recall the name. Actually, the "Cut" that they no longer make is to the prop shaft. Prop Shafts are subject to a lot of wear (cuts) where the strut bearing rides. By "sandwiching" the rubber (Neoprene, etc.) between two bronze bushings (one large, one small) they create a shockproof bearing that doesn't wear out. And the atmosphere they're working in is a lot more wear inducing than on a model A.
Terry

Originally Posted by Joe K

Cutless (trade mark) is the rubber bearing of propeller fame. The rubber is actually shaped with "ridges" and water is pulled into the interstice between the rubber and the shaft by the water's viscosity. The rubber compresses slightly in hydrodynamic pressure and the shaft actually rides on water.

It is a hydrodynamic bearing in its purest form - and doesn't even require oil.

But, for underwater applications (submerged in its lubricant) only.

Joe K

[Terry, NJ]

I was at the Leesport car show Saturday and I saw an old package of 4 rubber/ neoprene shackle bushings for a later Ford. Couldn't help but to think of this thread! They were a two piece affair that appeared to go into the spring from both sides with a bolt in the center. Wish I had my camera. The guy was loading up and didn't want to talk much.
Terry

[BRENT in 10-uh-C]

Originally Posted by Terry, NJ

I was at the Leesport car show Saturday and I saw an old package of 4 rubber/ neoprene shackle bushings for a later Ford. Couldn't help but to think of this thread! They were a two piece affair that appeared to go into the spring from both sides with a bolt in the center. Wish I had my camera. The guy was loading up and didn't want to talk much.
Terry

Those are the old replacement hangers that places like JC Whitney offered years ago. I think there is still an overseas supplier that imports those. Thanks for thinking about this though.