SOA Fj40 Questions - 55 Springs - "Measure twice cut once"

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Mine are 5 inches c-c in the rear. Maybe your rear springs are particularly saggy.
 
OK man, u have some issues here. Starting with the front suspension, get that fixed then address the rear. You are using fj60 rear springs up front correct? If that is the case, do u have the shorter ends of the springs forward for more wheelbase? Why didn't u do a shackle reversal? That is why it sits so high, when u do a shackle reversal and soa u drill a hole through the frame for the shackle and that significantly lowers the ride height. You can leave the shackle up front if u really want, but during compression your tire will eat the front fender lip hard. Also your shackle angle doesn't look good but it's hard to tell from the angle. Try to get your shackle at 45 degree ish. It's generally not a great idea to compensate for ride height with uneven shackles. Shackles move the axle fore and aft as the suspension cycles, having them of uneven length will cause one shackle to move the axle differently on one side. As u level out the rear it should level out the front. Keep in mind the springs will settle too after a few months. So don't worry a lot about getting it perfectly level. Putting the shackle through the frame with a shackle reversal, and removing leafs until the pack is basically flat should lower the front 3 or 4 inches. If u are going to keep the shackle up front, put on equal length shackles, pull out leafs till the packs sit pretty much flat, and move your fixed ends forward until u get a good shackle angle. Should get u about 2 inches lower up front. But I would really do the shackle reversal. It will mess with your caster and pinion angle, but u can always run shims to rotate the axle back to where u had the caster and pinion set.
Once u do that, then work on getting the rear dialed in, which it looks like it for sure needs. You will need a traction bar, there is a ton of torque applied offroad and then let will rotate.
 
OK man, u have some issues here. Starting with the front suspension, get that fixed then address the rear. You are using fj60 rear springs up front correct? If that is the case, do u have the shorter ends of the springs forward for more wheelbase? Why didn't u do a shackle reversal? That is why it sits so high, when u do a shackle reversal and soa u drill a hole through the frame for the shackle and that significantly lowers the ride height. You can leave the shackle up front if u really want, but during compression your tire will eat the front fender lip hard. Also your shackle angle doesn't look good but it's hard to tell from the angle. Try to get your shackle at 45 degree ish. It's generally not a great idea to compensate for ride height with uneven shackles. Shackles move the axle fore and aft as the suspension cycles, having them of uneven length will cause one shackle to move the axle differently on one side. As u level out the rear it should level out the front. Keep in mind the springs will settle too after a few months. So don't worry a lot about getting it perfectly level. Putting the shackle through the frame with a shackle reversal, and removing leafs until the pack is basically flat should lower the front 3 or 4 inches. If u are going to keep the shackle up front, put on equal length shackles, pull out leafs till the packs sit pretty much flat, and move your fixed ends forward until u get a good shackle angle. Should get u about 2 inches lower up front. But I would really do the shackle reversal. It will mess with your caster and pinion angle, but u can always run shims to rotate the axle back to where u had the caster and pinion set.
Once u do that, then work on getting the rear dialed in, which it looks like it for sure needs. You will need a traction bar, there is a ton of torque applied offroad and then let will rotate.

I have front fj60 springs in the front. yea I can't tell if the front spring angle is negative or not. I did not do the shackle reversal as I don't like the idea of compressing back and towards my Tcase as well as he direction of movement when going over obstacles it makes more sense to help force the rig up and over and not compressing back away from the object.

I'll look at it again tomorrow but even without the reversal in the front the back seems jacked up. I was not working on it today another guy was. I was back at work and trying to get this wrapped up.
 
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I ran shackle forward for a while myself. So your using fj60 front springs up front? They are shorter than the fj40 Springs right? Looks like the stock front leaf mount locations were used with the 60 springs which will give poor shackle angle. I can't really tell what's going on in the back suspension with that pic.
 
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I ran shackle forward for a while myself. So your using fj60 front springs up front? They are shorter than the fj40 Springs right? Looks like the stock front leaf mount locations were used with the 60 springs which will give poor shackle angle. I can't really tell what's going on in the back suspension with that pic.
Yea by 1/2 inch. Well see tomorrow
 
The back springs are just super super flat and maybe there are shot as the f-ing shackles are 12 inches long to keep the rig straight, front to back.

I think I might take a few leafs off my old set of Fj40 springs (3 inch lift) and add them to this fj60 pack to give them some more support and a small bit of arch. I know flatter the better but these have no support and are very very flat in the back
 
Front seems to be the picture is just a bad angle.

the back springs are just super super flat and maybe there are shot as the f-ing shackles are 12 inches long to keep the rig straight front to back. I think I might take a few leafs off my old set of Fj40 springs and add them to this fj60 pack to give them some more support and a small bit of arch. Try to bring the shackles back to 3-5 inches in the rear. Looking at the front that is almost
Mine are 5 inches c-c in the rear. Maybe your rear springs are particularly saggy.
Yea they might be shot, thinking about adding some leafs back from my Fj40 lifted springs to the bottom of these 60 springs so give some more support
 
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So called Cruiser Oufitters and got a set of new Dakar spring for the back. The ones I have are just shot. Almost negative arch. I think this will solve it and help with my Cruiser lean.

Still waiting on my rims and tires to arrive. Been 7 weeks. Tires to come next week, Creepy Crawlers 37x12.5x17. Rims still a few more weeks, all black beadlocks.
 
Well that worked! Fixed the Cruiser lean and the huge shackles in the rear. I bought one A spring and one B spring for the rears. They have a 1 inch difference in ride height.

The shackles are now 4.25 inches on all 4 corners.

I'll get pics when it's flexed out on the 37's that come this week.

For the money and the time I should have bought 4 new fj60 springs. I depacked the old springs. Had them media blasted. I slip plated between the leaves and POR the othe sides. Fronts are fine but rears were shot.
 
Well tires showed up but only 2 of my 4 rims....always somethin

IMG_2048.webp
 
Dang, @csd1982 , that looks awesome. Good work. Details needed!
 
Fj62 widened
RCV chromoloy axle
4x4 labs highsteer 6 shooter
4x4 labs six stud blocks
ARP knuckle studs
Fj80 TRE
6% degrees cut and turn
Aisin black lockouts with chromoloy inner hubs
Blisten Shocks
Ford shock towers
OEM Fj60 calipers and stainless lines
Fj60 front springs


2F
sm465
Orion
Tom Wood double CV drive shafts
Stainless steel exhaust with Y header

FF Fj80 rear
Blisten Shocks
FJ80 calipers and stainless lines
Dakar fj60 rear springs - A & B to correct Cruiser lean
Custom Triangular shackles
No kick bar

37x12.5 creepy crawlers
Method 17 inch beadlocks

To Do:
Fj60 power steering
4.88 gears (4.11 current)
Air lockers front and back
Bumpers
Rollcage
Gauge Cluster
 
Also I was thinking maybe not to use a anti wrap bar as the rear Fj60 springs have military wrap. Thoughts?

I think we're all distracted by your first set of shackle and missed this question. I would highly recommend an anti wrap bar. The military wrap won't keep your springs from wrapping.
 
Their are a lot of ways to attack a soa. I vote for the fj60 springs. As far as axles, stock fj40 axles are very narrow. If you compare a stock fj40 axle to body width ratio to modern trucks, the axles were much narrower than todays vehicles. It seems the trend is, if you take a new jeep for example, they have really wide axles, and then make up for that width so that the tires don't stick out by wheel back spacing. I personally like this concept because if you want a wider track width, you just change your wheels and then they stick way out. Right now I am at 63" wide rear, and like 61.2" front. I have wheels with only 2" backspacing. The stance is perfect for me, but I wish I didn't have to run wheels with that much backspacing. I think I would like to have ideally 64" front and 66" rear. Then run wheels with less offset, which would make for less scrub, and less stress on knuckles and trunions. As is though, I am nice and stable off camber.

I'm doing FJ60 width Diamonds on my front. Referencing scrub, I'd presume a wheel thats centered is ultimately best? As opposed to either more or less backspace? Just trying to wrap my head around scrub and stress on components
 
So I'm depacking and cleaning up these Fj60 springs I got now (sucks, takes forever but figure might as we, everything else on my FJ40 has been cleaned up a lot).

While doing this I wanted to see how much wider the Fj60 spring eyes are than the current springs I have on my Fj40. But when I put the Fj60 eye up to the current springs to see how much wider the 60's are they look as if they are the same width as the current springs.

I don't know what the PO did but my rigt is SUA and has 34's with no trimming. Lots of room.

See the pictures attached of the current front and back shackles. It even looks like the PO added some washers to make the hangers work with these wider shackles. Or am I just confused....I should have crawled under the rig to see the hangers on the frame rail as well.

View attachment 1309916

View attachment 1309917

Regarding the last pic, anyone have any opinions on welding the shackles together like that? Seems like it would tighten things up which might be nice on the highway, but then maybe a bit loose would be better on trails.
 
I'm doing FJ60 width Diamonds on my front. Referencing scrub, I'd presume a wheel thats centered is ultimately best? As opposed to either more or less backspace? Just trying to wrap my head around scrub and stress on components
First u need to know what size tire u are going to run. Then u draw a line through the upper and lower trunion bearing. If that line intersects with the center of the tire contact patch, that is the least amount of tire scrub u can have. I have a lot of tire scrub on my cruiser. The wheels stick way out and it's tough on the steering-especially when aired down. But I wanted more overall track width for off camber side Hills so I just added a use power steering cooler which helps a lot.
 

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