F-60 Shackles

[Mace]

Longer shackles won't solve that problem without going to a rediculous length.

Put a tape measure on the springs.. Spring eye to center pin on both legs (shackle to spring pin and spring hanger to spring pin) of the front spring and both legs of the rear springs.

There appears to be a reasonable amount of arch in the springs.. They are a lot longer than needed..

BTW, was this a spring "kit" that included everything? Are there supposed to be different shackles with the setup?

 

[lehiguy]

Longer shackles won't solve that problem without going to a rediculous length.

Put a tape measure on the springs.. Spring eye to center pin on both legs (shackle to spring pin and spring hanger to spring pin) of the front spring and both legs of the rear springs.

There appears to be a reasonable amount of arch in the springs.. They are a lot longer than needed..

BTW, was this a spring "kit" that included everything? Are there supposed to be different shackles with the setup?

Having built about a hundred sets of shackles, I can honestly say that you're wrong. I built progressivly longer shackles for the back of my rig, wanting to stay as low as possible with an SOA on OME springs, without shackle inversion like this guy has. A difference of 1/2 inch is all it takes to make the difference between a shackle that will invert and one that won't. Draw it out on paper and you will find that the extra 1/2 inch makes a huge difference in the shackle angle once the spring has flattened out completely. The math got me very close (I couldn't account for the weird arch of the rear springs with the off set pin, although it's obviously possible) and trial and error did the rest. So yes, a small amount makes a huge real world difference in shackle angle at maximum spring length.

 

[Mace]

Having built about a hundred sets of shackles, I can honestly say that you're wrong. I built progressivly longer shackles for the back of my rig, wanting to stay as low as possible with an SOA on OME springs, without shackle inversion like this guy has. A difference of 1/2 inch is all it takes to make the difference between a shackle that will invert and one that won't. Draw it out on paper and you will find that the extra 1/2 inch makes a huge difference in the shackle angle once the spring has flattened out completely. The math got me very close (I couldn't account for the weird arch of the rear springs with the off set pin, although it's obviously possible) and trial and error did the rest. So yes, a small amount makes a huge real world difference in shackle angle at maximum spring length.

That spring is not inverted...

 

[lehiguy]

That spring is not inverted...

No, but the shackle is, which means that the maximum distance between the rear spring mount and bottom of the front shackle is less than the eye to eye length of his spring when it's flattened out. Extra shackle length will cure that IF that's ALL that's wrong... could be something else. Usually there is a ride quality benefit to moving the shackle mount closer in towards the vehicle while using longer shackles and a good spring, like an OME. I've done three 60s like that. Those stock shackles are SO short, any spring with some decent flex will max them out.

 

[Mace]

Okay, so at rest, the spring is on the frame. There is still a considerable amount of extension that is necessary to balance things out. The other end of the spring is fixed. 1/2" of longer shackle is not going to fix the issue. From the pictures the spring will most likely extend another 2 inches or more during compression. So to solve the issue you would most likely need another 3 or even 4" of shackle. That, is gonna suck to tag rocks..

 

[ntsqd]

I decided to 'graph' this out and see where the shackle ends up. I had to make a couple assumptions:
1) My OME shackle is the same length as stock (Have no stock parts to measure)
2) At rest eye to eye spring length is the same as my OME's, 41.75"

 

[79fj40moneypit]

Call tom he should fix you right up.

 

[ntsqd]

Thinking about this on the drive in this morning, the spring eye to eye length can't be the same as my OME's. Changing the shackle length is not the solution and would introduce several problems.

Getting the correct length front springs is the solution.

Either that, or the shackle hangers on the frame have to be moved.

 

[lehiguy]

Okay, so at rest, the spring is on the frame. There is still a considerable amount of extension that is necessary to balance things out. The other end of the spring is fixed. 1/2" of longer shackle is not going to fix the issue. From the pictures the spring will most likely extend another 2 inches or more during compression. So to solve the issue you would most likely need another 3 or even 4" of shackle. That, is gonna suck to tag rocks..

I seriously doubt that his springs are too long. I had the same thing happen on the rear of my rig; the shackle inverted but there was still arch in the spring. (I had misjudged the length I needed) I had to drive 200 miles like that. I made a new set of shackles that were just 1/2" longer and it changed the geometry enough that the shackle was not getting flattened out when the spring was compressed all the way. Those shackles have been on there for several years now and they never inverted again. This particular incident may be something different, but how often has somebody installed a spring that was incorrect? The stock shackles were made for the stock springs which moved very little compared to what is available in the aftermarket.

 

[Dynosoar]

You have a rear spring on the front. The springs are too long.


Dynosoar

 

[bigrod]

FJ-60 Shackles

Well after talking with Tom at Hell Creek, he thinks i may need another leaf in the front springs to keep a better arch and maybe a little longer shackle. He is going to check around and let me know. So the saga continues a little longer. TOM at Hell Creek assures he will help get this lined out.

 

[Mace]

Well after talking with Tom at Hell Creek, he thinks i may need another leaf in the front springs to keep a better arch and maybe a little longer shackle. He is going to check around and let me know. So the saga continues a little longer. TOM at Hell Creek assures he will help get this lined out.

Have you ran a tape measure on them yet?

 

[wengejor]

Once you get it all straight can you post a pic of the truck from the side on level ground. In the Hell Creek thread some questions about the stance were never answered. It looked to me like the front end was higher than the rear in the first few installations.

https://forum.ih8mud.com/60-series-wagons/178706-hell-creek-suspension-fj-62-a-8.html