New front springs for shackle reversal, what to do? (1 Viewer)

[CruiserTrash]

This 60 came to me with a shackle reversal that was installed prior to the previous owner buying the truck in 2004. I replaced the rear springs a few months ago and the ones I pulled out were original to the MAF shackle reversal kit, so 20+ years old. I’m assuming the front ones are that old too. They’re worn out AND I think I can hear that the front left pack has a cracked spring. They need to be replaced, simple as that. Shocks too.

So … I had a chat with @lcwizard a while back about the SR system - he designed those for MAF. I suspected the springs would benefit from either being about 1.5” longer eye-to-eye or the rear mounts should move - the shackle stands straight up and down as it is, but would operate better if it were around 45 degrees. Dave confirmed that to me.

I have two options:
1. Get custom springs from Alcan
2. Buy off the shelf springs and move the aft hangers. I’d go Dobinson if I did this.

I’m a little gunshy on chopping up stuff attached to the frame, and while I do own a welder my experience is limited to building a bumper kit. The bumper has been bashed on rocks a few times and held up so I guess my welding did the job.

What should I do

 

[CruiserTrash]

This thread is not for debating the shackle reversal. Other than the old springs the truck rides great, steers and stops well. I know some folks hate the SR system but I’m keeping it. That kind of discussion can go on some other thread.

 

[lcwizard]

The primary reason I run shackle reversal on all the 60s I've owned is to get a 4" + lift without needing a 4" arch on the front spring
I don't notice a bad ride on a 4" rear spring but there is a noticeable difference between 2 and 4" springs up front.
The second reason is that on every one of the 6 FJ60s I've owned and wheeled semi rigorously or rigorously, the front shackle hangers
have broke of on either one or both sides. The last , 60 I had this happen to was 3/4 way down Holy Cross trail in Colorado. I was alone so I
had to chain the shackle to the frame and limp to the highway. If you take a good look at the way the shackle hanger is attached to the 60 frame , you'll understand
how this can happen. That said I do usually wait until I see cracking around the hangers before I do the swap. I've personally never gone over two years without
that happening.
Third reason, Coming off of the Cane creek trail in Moab, the last obstacle was a bank on a washed out creek. No shackle reversal on that 60 at the
time, stock shackles OME lift. No matter what angle I approached the bank, the shackle hit first and inverted. I would back off , pry the shackle out and try again.
The Jeep, Samurai and Toyota truck had to wait at the top while I stacked rocks to get the truck over the bank. You can dig a shackle reversal into
rocks or dirt all day long without that worry. Since I wheel alone 80 % of the time I build accordingly

Only the OME fronts seem short. Others have that same issue with or without the S/R. I haven't tried Dobinson since the late 90s when Terrain Tamer marketed
them. I've only seen threads about moving perches when OME were involved. That and their eyelet sleeves that shift and destroy bushings

 

[boots4]

If you don't want to relocate the hanger custom springs are your choice. I'd have no issues relocating the hanger to get a better angle on your shackle with whatever springs you decide to run.

 

[CruiserTrash]

@lcwizard as always, a wealth of information. I don’t know if you recall our chat a few months ago where we went into greater detail, but I think the synopsis is that with a proper shackle angle on the front the range of motion is equaled out between droop and stuff, and the road ride is a little better. And the way to correct the geometry is either longer springs or move the rear mount forward a touch. At least that’s what I took from it.

I think I checked the eye-to-eye dimension on the front Dobinson springs and they were essentially the same as OME.

 

[CruiserTrash]

If you don't want to relocate the hanger custom springs are your choice. I'd have no issues relocating the hanger to get a better angle on your shackle with whatever springs you decide to run.

Changing the hanger enables me to forever buy off the shelf springs. That’s the benefit I see there. The drawback is that I’m mutilating frame components.

I guess option #3 is find some springs meant for a different application that would work. I’m fabricating an example here, but let’s say 70 Series rear springs are an extra 1.5” eye-to-eye versus the front 60 springs, are the same width (to fit between the u-bolts on the perch), and the eyelets are the same O.D. (So they fit with the shackle & hanger). So far I haven’t turned up anything in that regard.

 

[boots4]

Moving the hanger is not really a hard thing to do. I see it as making an improvement, not a mutilation.

 

[lcwizard]

@lcwizard as always, a wealth of information. I don’t know if you recall our chat a few months ago where we went into greater detail, but I think the synopsis is that with a proper shackle angle on the front the range of motion is equaled out between droop and stuff, and the road ride is a little better. And the way to correct the geometry is either longer springs or move the rear mount forward a touch. At least that’s what I took from it.

I think I checked the eye-to-eye dimension on the front Dobinson springs and they were essentially the same as OME.

even a 1/2" difference is big. "Essentially" the same may be an improvement if it's even a little longer. I have mine built . i did run OMe for a while but I pulled the bottom leaf so it flattened a little. The ride was a vast improvement. It only dropped about 3/4" up front. That's about 1/2 the lift the S/R gives you

 

[lcwizard]

If you look at the individual leaf sizes , you see that the main leaf is 50" overall. You can see the shackle at rest in the no flex pic

 

[lcwizard]

sorry, the first drawing was the rears. here's the front. The main leaf is 46.25

 

[CruiserTrash]

Great stuff Dave. The photo of the shackle at rest is what I'm after. Currently my shackle is at 180 degrees, straight down. I think anything in the neighborhood of 120-135 degrees (30-45 from downward vertical) at rest is going to be a major improvement.

When you're saying the springs in the engineered drawings are 50" (rear) and 46.25" (front), what dimension is that? Looking at the drawings I see eye-to-eye distances (on center) at 43.36" and 41.63" respectively. Are you talking about the length of the springs eye-to-eye along their arch?

Also, these are the springs in the photos? Custom order through Alcan, or something you sent off to a different manufacturer? For what it's worth I still have the original MAF SR kit springs up front, or I'm 95% certain of it. When I removed the rears a few months ago they had a "Made in Canada" sticker and you confirmed those would have been original - hence I'm assuming the fronts are too. I wonder why the old kits came with front springs that would put the shackle dead vertical...

 

[lcwizard]

The flat measurement is what you're after with the 50 and 46.26
The Made in Canada were Standen springs. I had my last two sets made by Alcan to my specs as well as a set for my 40 that pushed the rear axle back 4" and were
5 inches longer than stock. I changed the shackle placement on the 40 for the loger prings
Your Standens were a little longer than OME as I recall. I worked with Betts on the next generation springs called the Mohave springs for man-a-fre , shown in
the drawings, but just as the project started , 2009 came along and the market crashed. Man-a-fre didn't ever really recover to the pre-crash days so the
springs only got two short runs with them. Betts tried building them in their India plant first. They had serious quality issues there so they decide to move it to their
Mexico plant but that run never happened. Now I build them as I need them. It's more expensive in the US but the spring quality is better and they ride like a coiled truck.
Alcan or Deaver could do the work. I even had Valley spring in PHX build one set quite a few years ago

 

[CruiserTrash]

The flat measurement is what you're after with the 50 and 46.26
The Made in Canada were Standen springs. I had my last two sets made by Alcan to my specs as well as a set for my 40 that pushed the rear axle back 4" and were
5 inches longer than stock. I changed the shackle placement on the 40 for the loger prings
Your Standens were a little longer than OME as I recall. I worked with Betts on the next generation springs called the Mohave springs for man-a-fre , shown in
the drawings, but just as the project started , 2009 came along and the market crashed. Man-a-fre didn't ever really recover to the pre-crash days so the
springs only got two short runs with them. Betts tried building them in their India plant first. They had serious quality issues there so they decide to move it to their
Mexico plant but that run never happened. Now I build them as I need them. It's more expensive in the US but the spring quality is better and they ride like a coiled truck.
Alcan or Deaver could do the work. I even had Valley spring in PHX build one set quite a few years ago

I think I like the option of going longer than stock for the springs, rather than trying to move the hanger. The longer springs would be, I imagine, a bit softer. So, looks like Alcan is the way for me. And then it’s on to choosing shocks to replace these tires old Ranchos.

 

[CruiserTrash]

Well I finally did it. Dobinsons HZJ75 front springs are the same dimensions as 60 Series springs but about 1.5” longer. The fixed end to center pin distance is the same so the axle stays in the same spot. The leaf packs had 7 springs and I removed two. Depending on how it settles I may remove another. The shackle angle is much improved. In the photos below note the front driveshaft so you can orient the front direction.

Before:

After:

The ride is much improved even with fresh springs and old shocks. Thanks to @lcwizard and Timelapse on IG for letting me bounce ideas off them.

For future SR folks: the HZJ75 springs are a great choice.

 

[White Stripe]

Nice. Make sure you check your driveline angle at full droop.

 

[CruiserTrash]

Nice. Make sure you check your driveline angle at full droop.

I will for sure. I had no problems with it before and there wasn't an appreciable change to the lift height, but it's still good to check. I need to check flex up and down to size for shocks anyway. Maybe I'll pinch my nose and go to a 4 Wheel Parts and use their ramp. OR else find a good loading dock or somebody with a forklift.

For what it's worth I had my front driveshaft rebuilt recently and they clearance the yolks so it would be less prone to binding. I think you're a Colorado guy so you might know Bill's Englewood Driveshaft where I had the work done. A good shop with a good reputation, and they've done good work for me in the past.

 

[matmattmatthew]

Interesting. This is a new subject for me, I also have a SR and 20+ year old leafs that I'm planning to replace. I got a really good deal on a set of lightly used OME springs from a rust-bucket part out, I was planning to use them with new shackles, shocks, bushings, end links etc. I didn't realize the MAF kit came with springs specifically for the SR. My SR is welded on, I'm not sure if it's the MAF or a homebrew kit.

And before anyone says anything, Yes, I am removing the body lift.

 

[CruiserTrash]

Interesting. This is a new subject for me, I also have a SR and 20+ year old leafs that I'm planning to replace. I got a really good deal on a set of lightly used OME springs from a rust-bucket part out, I was planning to use them with new shackles, shocks, bushings, end links etc. I didn't realize the MAF kit came with springs specifically for the SR. My SR is welded on, I'm not sure if it's the MAF or a homebrew kit.

And before anyone says anything, Yes, I am removing the body lift.

That looks more homebrew. Definitely not the MAF plates. It seems to be just the fixed end from the center of the truck cut off and welded to the front. Nothing wrong with that at all though. In any case you may not need longer springs for that. It depends on your shackles and the rear hanger, I can tell you my MAF SR plates are right at the front of the frame horns, another 4-5" forward from yours. I'd throw those used springs at it and see what you get.

 

[lcwizard]

Interesting. This is a new subject for me, I also have a SR and 20+ year old leafs that I'm planning to replace. I got a really good deal on a set of lightly used OME springs from a rust-bucket part out, I was planning to use them with new shackles, shocks, bushings, end links etc. I didn't realize the MAF kit came with springs specifically for the SR. My SR is welded on, I'm not sure if it's the MAF or a homebrew kit.

And before anyone says anything, Yes, I am removing the body lift.

post a picture of your pinion angle. Without a tall standoff you will pick up at least 5 degree caster unless the previous owner did a cut and turn

 

[matmattmatthew]

post a picture of your pinion angle. Without a tall standoff you will pick up at least 5 degree caster unless the previous owner did a cut and turn

I tried to measure it last night, it was a little hard because there wasn't a long enough flat surface to put my angle finder on. My best guess is that it's 8*.

Sorry for the crappy pic, I should have gotten a light under the truck.