The Stovebolt Site Forums The Shop Area Driveline correct shackle for rear spring?

Is it ok to use a shackle kit for the rear leaf springs with the single bolt though the middle, vs the ones with the double bolts (on a 57, 3200 truck)?

I ordered replacement shackles from LMC and they finally arrived yesterday (a week late). It was difficult to see that they were different went I ordered, and I'm concerned about how strong this version may be? The ones that were on the truck have nuts on both of the bolts, like the ones at classic parts. Ive attached photos of both versions to this thread - hopefully they show ok.

Are the ones I received really for a 57 3200 truck? Has anyone used them and confident they work well? It just seems obvious to me that a single bolt in the middle is not as stable as the double bolt option. Yes the single bolt still has the upper and lower bearings and they look like they'll be held in place by compression from the single middle bolt.

I'd use the ones I took off, but Ive tried everything to get one of the bolts out of the spring eye and it won't budge. Its seized / rusted in place (yes I'm trying to thread it out, not bash it out - but there is really nothing to grab without damaging threads.

I'd like to get the install complete today, so once I hear they are ok to use I'll get started. But if needed, I'll order the right ones and just wait to get the truck back on the road.

I used the same style on my ‘52 with good results. The ends of the shackle pins are tapered and when you assemble, you need to tap them on to seat them, then secure them with the single bolt.

I do see your dilemma. I think they would work but if I was you, I would replace with like and kind.

You could always try to double nut the pin to remove. Soak the pins with a penetrating oil for several days and tap the pins lightly with hammer occasionally, soak some more then try the double nut trick. Patience pays off with this method.

Thanks Phil. I have sprayed PB Blaster on the pin and tried the double nut method. They are in solid. Just not a good surface to grab with vice grips or channel locks without destroying the thread. Last thing would be heat, but I don't have a torch handy. I will of course try again today before moving forward. I may be overthinking the potential weakness of the shackles. I don't have a lot of experience with them to know if the stresses are significant enough to cause the shackle to bend or twist. I imagine the version with the nuts on the pins exists for a reason.

If you use a torch, try heating them just a few hundred degrees and then soak them again in penetrant. It will help draw the penetrant in.

You'll probably want to replace the bushings as well as the pins. so a ball joint press would work well for that. You can rent one for just a deposit at most auto parts stores.

I have used the kind with the nuts on the ends of the pins many times. They are much more secure. Some catalogs list them as heavy duty option. Make sure the shackles are the same length.

George

Starting with 2nd series in 55, the leaf springs are wider than the previous years. That is a huge difference in the shackle kits. Problem is that if you try to order the earlier shackles, some vendors (Rock Auto, and NAPA) in my experience ship the later wider versions thinking they will work.

Yep, I just gave up on the project for today. The old shackle pins are no good (one of them has lost most of its thread from corrosion, and the new ones won't thread into the bushing that's left in the truck (rear leaf spring mount). So now I'll have to remove that bushing. I'm not sure how I'll fit a ball joint press up in there. Happy to hear of any insights on how to best do this?

This is original shackle set up on my 59', the pins and bushings came from LMC. I used a threaded rod and 2 sockets to press out the old bushings and install the new ones, worked very well.

I have the same ones with the nuts on both ends. I just got my new bushings pushed in with an all thread tool from another post. On pushing int the front pass side, I noticed that the piece that pushes in the bushing is cracked:/

Awesome, thank you. I needed that reminder of how to do it. I have some threaded rod in my tools as Ive used it to press in bearing for bottom brackets on bikes. I'll still search for the post to see how they used it for the bearing on the Spring mount so I can be sure not to mess it up.

Interesting. I'll look at their site again and see if they have the pins and bushings. They probably do and I missed seeing them vs the complete kit. All I needed was the pins and bushings of course. Also thanks for the rod and socket idea! I had tried a socket but realized I didn't have enough room to get a solid blow (or several) with a hammer. I've already taken off the side step and had to cut that hardwear, and lifted a plank from the bed to move a wrench, and the handbrake cable. I'm not wanting to remove anything more just to swap springs.

Kiwinz...a piece of all thread with nuts and a section of pipe worked slick on removing and replacing my spring/shackle bushings. I R&R all four on the rear in about an hour.

Thanks all. Well I finished the project, but not how I wanted it to go. I tried and tried to remove the bushing with the home made press (all thread) and even applied lots of heat with a butane torch. No luck. So it was a mess getting the truck back on the ground, using some of the old parts to get it finished.

Remember I had the original shackles with the bolts and nuts on the upper and lower pins (much more solid). The new shackle kit had the single center bolt style, with the upper and lower pins held in via compression (not ideal but I wanted to get this done and decided to use them). In the end I had to leave the old threaded bearing in the spring mount on the truck. It would just not budge. I was able to get the old pins out, and got one of the pins out of the old springs I removed. They were not reusable as the threaded ends got slightly stripped. So I decided to leave the old threaded bearings in the truck spring mount, and use the new shackles.

The new shackle pins have no thread on the end, and the old bearings were not as smooth as they needed to be, so it was impossible to just grease them up and thread in the new pins, and there is nothing to grab on them to help turn them. I applied PB blaster, scrubbed them with a small brush, used more heat etc. The new bearings (which I could not use) accepted the new pins easily and the old pins, so I knew it was the same thread. I didnt have a thread chaser (I forget the correct name) large enough in my kit, so I went to Ace hardwear to buy a larger enough bolt to use to thread in slowly to clean up the thread of the old bearings that remained in the spring mounts. Problem was, even ace with all their sizes could not find the correct thread. Seems its metric, but not a common pitch? So I ended up using the old pin with a forced nut on the end as a chaser. It went in fine enough back and forth. But the new pin still wouldn't go in very far. I know it's a tight tolerance. So with a sliced older bearing as a sleeve to protect the thread, and vice grips, I had to work it in. It took a long time to go back and forth and lots of lubricant and small moves with the vice grips to get the pins in (hours). That was the hassle of the entire project. I don't like how the pins are compressed with one bolt, but the rest of a simple spring replacement went easily and fast. The front bolts were a breeze. Old U bolts were fine, and everything else just bolted right up. Now for the bad and frustration...

1. I had to remove the side steps to get space to remove the front pin. The bolts were rusted and most broke, including the round button head bolts that go through the top of the step. I can't find replacements for these. Anyone know where i can get them?

2. With the new posi springs in place, and new shocks (stock Monroe heavy duty replacement shocks from LMC, but do not seem like heavy duty), the truck sits lower. I like the stance, but its also just as soft and squishy as before. Maybe more. Its even closer to the tires now. So I'm back to looking for airbags or load assist shocks, or air shocks to allow me to carry anything in the back, and to allow me to tow a trailer.

Anyone have the model number of air bags they've used. I know I'll have to modify some parts, but the least mods the better.

Thanks if you read this far.

I did the same project on my 56 a couple of years ago and had some of your same issues (I still have one shackle on the rear that I have been unable to remove). My original shackles had just the single bolt holding them together, so the parts from LMC matched at least. The bolts on the bottom of the step are called carriage bolts and you should be able to find them at a good hardware store.

Lee.