Does it matter what type of bolt I use to hold the leafs together in the middle? I've cleaned up one spring and have started painting. Also I have finished painting my frame!

 

Nathan,

I've made my own spring bolts in the past (although they aren't that expensive at about $3.00 each). I used grade 8 bolts and just rounded off the edges off the bolt head on a grinder so it would fit down into the spring perch.

 

Vern's got the ticket. Grade 8 is the only way to go here, Nathan. Make sure you use a grade 8 nut as well.

If you can find SHCS (socket head cap screws) you don't have to do any mods except cut to length after assembly. McMaster-Carr (www.mcmaster.com) has them

Part number: 91251A395
Alloy Steel Socket Head Cap Screw 5/16"-24 Thread, 3-1/2" Length, $ 6.16 per Pack of 5

You might need a slightly different size for your springs but they have them in practically any size you would need. The shipping for a single package may be a bit steep but you can check on that. Any local hardware places that might stock SHCS bolts?

 

dont know if ya have them up north but i got mine at a ace hardware i bought the allen head grade eight bolts and they worked just fine the fit in the spring pad is good also


just my two cents worth

 

Yup George, the Allen-head is the same as an SHCS. I agree the fit in the pad is just fine.

 

I've been considering what I'm going to do about this issue when I get to this point. The 9" will be hung with 5 degree pinion shims between it and the springs. The alignment hole in the axle is quite a bit larger than a 3/8" SHCS would be and the hole in the shim is actually a very large slot. I'm not sure how I'm going to get it all lined up square, tightened up, and still keep the shim from slipping back and the axle from moving around. Do you guys think there is enough clamping force in the u-bolts by themselves to keep it in place or should I be having custom spring bolts made to more precisely fit the axle? I've never given this any thought as all my previous axle swapping experience has been with coil springs. Keep in mind that this thing will be under a lot of stress with the drivetrain that I've got planned. I'd hate to have the truck dogtracking or have a pinion shim walk it's way out after a few hard stop light holeshots.

 

Joe,

If I'm imagining the parts layout correctly, you'll need the spring pack center bolt to extend through the slot in the shims and into the axle locating hole, right?

One way to do that would be:

1. Install a longish SHCS bolt with its head on top of the spring pack and a nut on the bottom
2. Cut the bolt off so the end of the bolt will sit at the bottom of your axle locating hole with the shim in place
3. Install and tighten extra nuts beyond the first one until the whole threaded end is filled with nuts
4. If the slot in the shim is big enough, the nuts on the bolt will fit through it
5. Grind the last nut (or two) so they just fit in the axle locating hole

That lets you get the springs all assembled and you can then install the shims and axle without too much fuss. The shims might move a little due to their slotted holes but they will stop when the end of the slot hits the nuts on the spring pack bolt. It doesn't matter, though, since they are the same angle no matter how far forward or back they sit on the perch. Does that make sense?

 

'rage

I don't know what style shim you are using but it sure doesn't look like an issue with mine.The head on my spring pack bolt sits nicely in the hole on my pinion shim. It looks completely correct after everything is together. Of course I get to do it all over now that I bought drop shackles. May not even need the shims now with any luck. BTW 5 degrees is a lot. Have you actually measured this with the rear suspension loaded a bit. George is correct, the angle won't change until the shim flies completely out, which it won't.

 

The bolts originaly had the nut on the top. Right now I'm working on the front springs. I used a 2 1/2 5/16 bolt. It looks nice in gloss black and nice shiny bolts. The 2 1/2 bolt was almost just perfect. If it had just 3 more threads it would be for lack of a better word perfect. I have now painted the front axle, and a whole bunch of frame and spring related parts. My post was highjacked!

 

Nathan,

I'm very sorry about highjacking your thread. Please have a seat, fasten your safety belt, and enjoy the little detour. If you play nice and smile pretty, I promise we won't shoot you and toss your corpse out onto the tarmac when we arrive.

Dewayne and George,

You guys are going to have to explain to me how the angle remains the same no matter the fore and aft location of the shim. The shims are essentially just aluminum wedges. I got them from Napa. If the wedge slips forward and out from between the spring and pad, the axle would almost have to rotate back up to follow it. I must be missing something.

As far as making everything align to the spring pack bolt, Well, you'd just have to see this to understand my concern. The alignment hole in the axle is MUCH larger than the old Dana 44 - I'd guess about an inch. I don't even think that nuts would give me enough diameter on the bolt to make it close. I probably ought to take some pictures so you can see what I mean when I get all these parts drug back out and ready to re-install. I may grab a hunk of aluminum at work and try to make a couple bottle cap-ish adapters in the lathe. I had talked to one of the machinists about custom making me a couple of bolts with big enough heads, but he thinks that it's going to be a pretty tall order to cut a grade 8 bolt down that small without bending it with the tooling. He suggested mild steel and then taking them over to the die shop to be heat treated and hardened. That sounds like way too much messing around for two stupid fasteners. How am I the only guy that's run into this?!?

 

Could you just make a little plate with the correct size hole and weld it over top?

I might as well take the detour too.

 

'rage

You could bush the hole with about anything. Once you get it all secured, it isn't going anywhere. Don't get wrapped around the axle on hardness of your shim. You should be able to find something hard, but even mild steel would probably even be OK once you get it all tightened down. WRT the angle, if the wedge came out significantly (like halfway) , and the U-bolts were then retightend, the angle could change I suppose because some of the meeting surfaces would no longer have any shim. But that isn't a realistic scenario obviously. Minor movement isn't going to change the angle.

I have taken apart a zillion leaf springs where the center bolt was completely broken and the springs were still about where they were supposed to be upon disassembly..

I would like to see what your shim looks like I guess. Mine isn't going anywhere, and it's aluminum BTW, intended for this application, if that tells you how big of an issue hardness actually is.

 

Rage,
You are correct in your thinking. Here's the answer to your problem. I am running a 9" with the 5' shims (may have to go to 7.5') in my '50 F-1. Use a NOS spring bolt. The head will be the correct diameter and the bolt will be long enough to pull the leaves together when you assemble the spring pack. You will see the problem when you go to mount it to the axle. The head of the bolt is not long enough to reach through the shim and into the spring perch. I ground a bevel on two sides (sharpen like a chisel) and found a small piece of rod that I ground the same bevel on. Butt together and weld them. You can turn everything to size in a lathe or use a toolpost grinder. ( I used a crankshaft grinder, but that's a bit of overkill) Once you get the head sized to fit the hole and long enough, you're ready to rock and roll!

 

'rage

I reread your post. Your shims are definitely different than mine. I had to drill the shim center hole out a little so it would fit over a 3/8 hex nut. They really can't move much. I don't now whats going on with your 9" perch either for that matter but it sounds like Don has you covered. I keep forgetting you don't have a 53-56. Sounds like your angle is much more significant too. Sorry for confusing the matter for you.

 

Thanks for the pointers and ideas. Dong actually hit on a problem that I'd forgotten all about. With the shim in place, the bolt head isn't deep enough to pass through the shim and catch the spring pad in the axle even if it were the correct diameter. In the bif scheme of things, this is a minor problem and I'm not staying awake at night worrying about how to fix it, but it is one of those myriad little question marks that I will have to face in the somewhat near future and try to think about from time to time.