Last year I rebuilt the rear springs on my '53 panel. New bushings, shackle pins, cross lock pins, grease fittings and poly-liners. Last week when doing a grease job I noticed that one of the shackle pins was coming out. I was able to get it re-indexed and back in, but it seems like the cross pin is too loose and is not holding the shackle pin the way it should. I tried putting a 1/2 bolt through the cross pin hole but it doesn't hold the shackle pin either.

Does anyone make oversized cross pins? Any other ideas about how to fix this?

 

I have to wonder if you're putting the locking pin in all the way, or if the shackle pin isn't in all the way, so the groove is lined up with the locking pin? I don't see any way the locking pin will let the shackle pin get past it otherwise. Can you take a pic of the locking pin when fully inserted, showing how deep it's in?

 

Yeah, I checked the shackle pin to be sure the groove was lined up and the pin is going all the way in. The locking pin seems to be loose in the hole. The other locking pins had to be hammered in to get them to lock on the shackle pin. This locking pin just slips in to the hole all the way without any hammer. I tried some of the old locking pins, but they were the same.

 

How far out does the shackle pin move? Does the locking pin ultimately prevent it coming out? I'd say the shackle pin groove was machined too deep or too wide.

 

The shackle pin gradually works it way out from the action of the spring. Right now it's out about 1 inch. I can't pull it out but it will work it's way out if I continue to drive the truck. When I first found the problem when doing the grease job the pin was out about 2 1/2 inches. I don't think the locking pin was doing anything. Right now I have a 1/2 bolt in the locking pin hole and it is also not preventing the shackle pin from moving.

The new shackle pin was from midfity and looked the same as the old pin including the groove. The old pin was in there for 63 years... Strange.

I think I might try to shim the locking pin and clean up the old shackle pin and re-install. Just not sure what to use for the shim. Maybe half of a cotter key?

 

I agree with Ross a picture is worth a 1,000 words. If the locking pin won’t hold the shackle pin, I’d be afraid you’ll have to replace the shackle mount.

 

This is interesting because I'll be fitting the rear springs and shackles today or tomorrow. Will post if I have any similar problems.

 

Wow, the shackle pin must have been almost ready to fall out?! Does the old locking pin engage it any better? I would honestly contact MidFifty and ask for a new shackle pin and locking pin.

 

I guess I could try to get a picture. Not much to see, the the shackle sticking out of the mount about an inch.

I am not sure replacing the shackle mount would do anything. The shackle pin mounts into the brass bearing which is hammered into the shackle mount. I think the issue is the locking pin and locking pin hole.

 

Yeah, my eyes got real wide when I went to attach the grease gun.

I haven't tried the old locking pin yet. Wanted to have a plan before I pull it all apart.

I may give MidFifty a call and see if they have any advise.

What about grinding a new smaller slot on the shackle pin? I could grind it on the opposite side of the current one. Maybe the locking pin will grab then.

 

I can't imagine how the shackle pin can get out past the locking pin or the bolt, or that you can even get a 1/2" bolt in thru the groove. Surely some of the shackle pin beyond the groove would have to get past the locking pin or bolt, which I just can't see being possible.

When you are pushing the shackle pin into the shackle, watch the end of the shackle pin thru the hole where the locking pin goes. Does the shackle pin block part of the hole?

When you get the shackle pin out, please post a pic of it showing the depth of the groove.

 

I am also at a loss to explain it. The other 5 pins and lockers are fine. As I recall this was the worst shackle pin to get out. Pounded on it and used mild heat. Still took 2 hours.

I am going to pull it apart this weekend and I'll report back.

 

I had some time this morning so decided to have a look at this.

I removed the 1/2 bolt I was using as a locking pin and removed the shackle pin. The notch on the shackle pin looks fine, about the same as the old pins.

Re-installed the shackle pin and double checked to make sure notch was lined up with the locking pin hole. Went through all the locking pins and found the one that seemed to be thickest.

When I install the locking pin it pulls through the hole till the threads bottom out. I tapped on the shackle pin and I could push it out about 3/16".

Put a shim on the locking pin (a thin cotter key) and re-installed. The locking pin seemed to tighten up. Shackle pin still moves out about 3/16" but doesn't seem to come out.

Guess I need an over sized locking pin.

 

It looks like the hole on the outside of the spring hanger is elongated. (See the picture below.) This should be a snug fit.

Is there a chance the inside hole has been damaged as well? Maybe the pin has too much room for the locking bolt to tighten up.

 

I see what you're saying. You think the shackle pin is moving in the holes in the holes of the hanger. I thought the pin and bushing were designed to wear before the hanger, but you maybe right.

Here's a pic of the shackle pin pushed all the way in: