I don't want to hijack the original posters thread so I will try to contribute to his questions and then ask some questions that I hope may be helpful too. I have never owned a SOA rig so you know but I have been on an off interested in doing a SOA on a 45 project I am planning.
My Pros
- I have been considering it because I want to add some lift to my project
- I like the clearance you get from moving the springs over the axles
- Undercarriage looks cleaner to me with SOA
- Possibly a cheap way to lift it if I do my own fab work (SUA lift kit is about $2200 for 2.5inch)
- Good if I don't have to alter the steering
- New to me reverse curl leaf spring eye lowers the SOA lift
My Cons
- I only want 2.5 to 3 inches of lift to run 33" tires, this may be to much lift for that
- I really don't want the tire size to look disproportionate to the lift and I really want to stay with 33s
- Expect I would have to alter the steering for hi-steer
- Have additional fab work required
- Higher center of gravity compared to a SUA lift
I am still on the fence at this point but would like to know if anyone has seen a 40 series SOA with the reverse curl eye leaf spring. Looking at the links provided by
@jim land it says it dropped the height about 1.5 inches. So if a normal SOA giver you about 5-6 inches of lift this could get it down to 3.5 to 4.5 inches. I think the lower side of this maybe ok with 33s. Although the the rear spring pack on a 45 is pretty thick compared to a 40 spring pack.
Asking those that have done this do you think a SOA that resulted in 3.5 to 4 inches of lift would need a high steer set up?
If anyone has picture of a 40 lifted with reverse eye springs please share.
I am not interested in altering the 45 frame with a shackle reversal or running the shackle through the frame so the SOA would use the original spring hangers.
Please share any known tricks for doing a SOA that will help keep it low.
Another known trick not mentioned in this old thread is “frenching” the leaf perches on the housings down into the axle housings. You can easily gain 1-2” that way without frame mods but does take good fabrication and welding skills.
Building your own leaf pack can also help.
As mentioned, shackle sleeved through the frame.
You can also french the leaf hangers into the frame but obviously you are doing frame modifications then.
It seems these days if you want to run up to 33’s, keep it SuA and just run a lift. That is all good and no worries at all. Although caster will still be out of whack.
A lot of people though seem to run the 4+ shackle reversal and lifted springs to get 4+” for 35’s. And SoA is reserved for 37’s.
I have done a number of SoA including fixing a botched job and also did the 4+ SR kit with 35’s. I cut and turned all of them, even the SuA. Caster is key in all this and the only way to get it right is a cut and turn. 4-5* on 35” MTs on grooved-rutted pavement (worst conditions for caster and tracking) at 65+mph, it will track so true you can two finger the steering wheel no worries.
I am getting ready to do another right now, on a 45 and my plan is to keep it as low as possible without modifying the frame. I am just not a fan of the 4+ kit or 3”+ lifted springs or long shackles. I am aiming for 4-5” of lift with excellent on road and off road drivability.
I also read a lot of people on the 40-series Facebook page either think these trucks are supposed to drive like crap or can not understand how to fix it. Caster is everything as well as at the very least getting rid of as much slop as you can in the stock steering. Personally I feel getting rid of the stock steering and going to a standard crossover makes a huge difference. I always shoot of 4.5* of caster and it hasn’t failed me yet. In a SoA set up a rear traction bar is really needed as well, pinion deflection is brutal without it.
These trucks can drive excellent in all conditions on and off road but it really needs to be done right. SuA with shims for caster to me is a bandaid. The 4+ kit causes more problems than it is worth in my opinion. To much arch in the springs like a 4” HFS kit will ride like crap, extra long shackles create problems too. You also got to have the right shackle angle SuA or SoA.
So yes it takes some work and some money and some education to get it all right. I can absolutely guarantee though that these trucks can drive absolutely outstanding if set up correctly. If you haven’t been in one or better yet driven one set up right you might be surprised just how good leaf springs can be, SuA or SoA. Seems like the latest rave with 60-series is 80-series coil conversion and I get it, I have done those too and they do ride great but again, a properly set up leaf springs suspension might surprise you.
Cheers
