Ironman 4x4 lift on an FJ43 (1 Viewer)

[jmac3]

@jmac3

you ask for a photo of my shackles after the OEM install.
Slight angle in the front
Almost perpendicular in the rear. Full pack, no leafs removed and a hard top.

hope they help……..


devo

View attachment 3227697

View attachment 3227698

thanks for posting the pics. I am surprised to see that OME has given you a similar angle to my Ironman4x4.
How is your ride?

 

[devo]

The ride compared to the 41 year old Toyota springs….wonderful! Especially on washboard roads.

 

[Polecat]

So the springs are on the truck now, and I got the promised 2.5 inch lift.
I realize that I am using heavier springs and I am taking this all with a grain of salt, but unfortunately the spring hangers are verticle now.
I reached out to Ironman4x4 and they told me I need to get about 250 miles on them to break them in.
So I have about 500 lbs worth of crap in the back of my truck and I am bouncing around my neighborhood trying to break them in!
The ride is quite harsh for me at the moment and I really hope they settle down a little...


View attachment 3224691

@jmac3

you ask for a photo of my shackles after the OEM install.
Slight angle in the front
Almost perpendicular in the rear. Full pack, no leafs removed and a hard top.

hope they help……..


devo

View attachment 3227697

View attachment 3227698

thanks for posting the pics. I am surprised to see that OME has given you a similar angle to my Ironman4x4.
How is your ride?

Both of these quickly will settle in quite a bit. In my experience, even better than 500 miles of on-road break-in is a day or two off-road, really letting everything flex and compress. You’d be surprised how much things settle.

I have a set up including Dobinsons springs and shocks and longer BTB shackles on order. I’ll join the comparison after I get everything installed, but I’m expecting the initial shackle angle to look pretty similar to both of these.

 

[jmac3]

Both of these quickly will settle in quite a bit. In my experience, even better than 500 miles of on-road break-in is a day or two off-road, really letting everything flex and compress. You’d be surprised how much things settle.

I have a set up including Dobinsons springs and shocks and longer BTB shackles on order. I’ll join the comparison after I get everything installed, but I’m expecting the initial shackle angle to look pretty similar to both of these.

Good to know thank you

 

[jmac3]

Good to know thank you

So I have been working quite a bit to make the springs work with my truck.
I have learned there are WAY more variables to work with than I could have thought...
here are some things I have used to make my choices:

How much does my truck weigh at each wheel?
Interestingly - almost exactly 900 lbs at each corner.
How much weight are the springs carrying at each corner? remove weight for springs wheels and axles...
Front: 670
Rear: 630 (rear springs are heavier)

What is the spring rate of my springs? (starts getting deep here!)
I could not find published figures for this, so I decided to make a test rig:
I hooked a scale in line with the chain... actually worked pretty well.
What I learned was that the site SuspensionMAXX Leaf Spring Rate Calculator :: SuspensionMAXX - https://suspensionmaxx.com/leaf-spring-rate-calculator is actually pretty close for my springs.

 

[peesalot]

IMO looks good, get 400lbs of gear and a passenger and the angles will be spot on.

 

[jmac3]

I only experimented with the rear springs and my modified pack seemed to add up very close to the numbers that the website generated (below)
Additionally, I am sure there is a much more complex formula for understanding the impact of the progressively shorter springs in the pack but the front spring pack is movable without needing to put 5000lbs on it.

FRONT LEAF Spring Rates - Top - down
2x43" : 132lbs
1x38" : 96lbs
1x32" : 160lbs
1x26" : 299lbs
1x18" : 902lbs (I assume these shorter leaves are acting more as an anti-wrap than a spring but they are arched the same - not flat)
1x11" : 3952lbs (obviously very difficult to bend)

REAR LEAF Spring Rates - Top - down

2x52" : 75lbs *
1x51" : 40lbs *
1x48.5": 47.5lbs *
1x45.5": 58lbs *
1x38.5": 96lbs
1x35" : 123lbs
________

HELPER Pack - absurdly thick springs start supporting as top springs get closer to flat...
1x30" : 756lbs
1x22" : 1917lbs
1x14" : 7439lbs

MY REAR Pack (haven't modified front yet)
I removed the lowest/shortest 2 springs from the rear 'main' pack as well as the 2 shorter helper leaves and my spring rate was about 225lbs per inch
so without anything in the truck, the spring will sit about 3" compressed. I did this because my truck will almost always be empty - i do realize it will likely droop a little in the back if I load it down. If it's too saggy I will swap th 45.5" with the 38.5" leaf and firm it up.

SPRING RATE/RIDE HEIGHT
The concept of thinking about spring rate in relation to how much of travel at normal ride height was the real eye-opener for me. It is one of the simpler ideas - use the vehicle weight (that is carried by the spring) in relation to spring rate- how much weight to push the spring 1 inch... then figure out how many inches of the full range of the spring you want it to sit... that would be your desired spring rate. I wanted mine to take up about 3 inches of total spring travel at ride height... that gave me a target spring rate of around 630lbs/3 inches.... or 210lbs/inch. Closest I could get is 220.5.

 

[jmac3]

REAR SHACKLE ANGLE

Ironman manufactures the rear spring length 1320mm with the pin right in the middle.
The FJ45/43 hanger points measure 1265mm. So if the rear spring is completely flat - which is probably unusual... then the spring eye would be pushed beyond the shackle mount by 55mm (a little over 2 inches).
It seemed to me that my rear shackle was always going to be sitting close; to verticle...
I decided to consider the max length of the spring flat (1320) and then picture that with the shackle hanger almost straight back... then measured 3" (how long my shackle is) in on the fram to get the better position for the hanger... fortunately and unfortunately, my hanger mount was in terrible condition so I had an opportunity to move the hanger position:

 

[Greek Cruiserhead]

Any update?

 

[jmac3]

Any update?

Thanks for asking.
I ended up with removing all helper springs plus #5 and #6 in rear. (Riding empty is good but i probably need to add one leaf back if I'm going to carry any load). That's in addition to bringing the hanger in a couple inches. Front spring I moved hangers back about 2 inches and removing the bottom leaf in the front.

 

[Greek Cruiserhead]

Thanks mate and nice that you got it to work!

PS. May I guess that the problem did arise because the kit you "grabbed" was for the long wheelbase (J45) and not for the short/middle wheelbase (J40/42/43/46)?

 

[jmac3]

Thanks mate and nice that you got it to work!

PS. May I guess that the problem did arise because the kit you "grabbed" was for the long wheelbase (J45) and not for the short/middle wheelbase (J40/42/43/46)?

Yeah that was a ton of work... According to Ironman I purchased the correct springs.

 

[jmac3]

Yeah that was a ton of work... According to Ironman I purchased the correct springs.

But getting the shackles at that angle makes the ride SO much better!