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SOA and SR....spring hanger concerns

Discussion in '40- & 55-Series Tech' started by dylanray, Jul 28, 2017.

  1. dylanray

    dylanray

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    I have search and read and searched and read an I still cannot find a really good answer.

    I currently have my rig down to the frame, it has a s***ty shackle reversal from the PO right now and lift springs, caster and pinion are beyond terrible.

    I purchased the SOA kit from RuffStuff, I am about to order OME 60 springs for the rear and OME 40 springs for the front. I am going to remove a few of the short leafs to keep height down and ride smooth until they start to sag.

    Before I weld the new spring hangers all the way around I need to know a few things...With the SR are both ends of the spring (fixed end/front) and the shackle end (rear) supposed to be level (on the same plane)? Or will it really matter since I will cut and turn the front axle to get the correct pinion and caster per my application?

    I also know that with the 60 springs out back I will need to move the rear (shackle) end spring hanger aft. One I have the front end SR spring hangers in place it should be easy to measure out and make sure they are all in the correct place, but in the Ruff Stuff kit what will help me keep them all square (90 degrees) to the frame? I have not received the kit yet and have only seen pictures.

    Any help with these last questions will be greatly appreciated. And yes I know the opinion of most people in regards to using OME springs on an SOA but after seeing a few done this way in person by 2 guys who build a lot of rigs I am confident that is the route I will be taking.

    Cheers,
    D
     
  2. Burbot

    Burbot

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    You will get better advice if you post some pics. There is lots of expertise out here.
     
  3. White Stripe

    White Stripe

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    How you mount your hangers will determine the angle of your leaf spring and the angle of wheel travel. Depends on what you want. All suspensions move in a arc or angle throughout their travel. In addition it will affect how the tires hook up on a obstacle, as well as braking and acceleration. Having the leaf springs level reduces brake dive. I angled mine back because I believe it absorbs and climbs at the same time. Here is a Campbell enterprise built fj40 with leaf springs. Might give some ideas...
    1970 Toyota Land Cruiser - Brad's Bold 40 - 4 Wheel Drive & Sport Utility Magazine
     
  4. pjohnson

    pjohnson SILVER Star

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    The Ruff stuff kit isn't designed to accurately place your springs in the correct place on the frame or in relation to each other. You have to do that yourself. Measure , measure, measure, tack, measure, etc. You get the idea.

    I have heard of using pvc pipe to help with keeping the mounts square.
     
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  5. Toyoland66

    Toyoland66

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    What are your goals for the vehicle, tire size, intended purpose, are you stretching the wheelbase?

    SOA with lift springs is gonna be around 8" of lift. I would try to reduce the amount of height the spring mounts add as much as possible, I.e. French them into the frame or similar.

    With 8" of lift you should be stretching the wheelbase as much as possible and installing wider axles, it will be unstable otherwise. Know that if you run big tires on shallow backspaced wheels you will be eating trunnion bearings.
     
  6. lcwizard

    lcwizard Supporting Vendor

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    In theory the spring eyelets are supposed to be level so the shackle height needs to be factored in. This is the reason the front towers in a commercially designed SR kit are so tall. The forward end of the frame is much higher. Even the kit brackets aren't tall enough to be prefect.
    For a leaf spring system to work properly the axle has to travel in a perpendicular line from the ground otherwise the axle will steer in corners or
    compression and droop. Slight variations aren't really noticeable in something like a Land Cruiser but it is the thing that would give Porsche guys
    fit. It's referred to as under and over steer..
    With a shackle reversal the wheels would travel forward in droop and rearward in compression. This is already an issue with the stock slip yoke
    only being 2 3/4" long. Start tilting the axis of the axle path , pulling the top of the travel backward and the bottom forward, and the
    problem is exacerbated.
    Now picture a vehicle in a hard right turn. As the body leans the left tire begins to compress and the right begins to droop. The axle will
    steer out of the turn. The softer the springs the more effect. By no means does this mean you can't control the truck. We all get used to steering quirks in each car. They all have some level of under or over steer but when you're setting something up why not get at least close to correct. I'd be as concerned with the slipyoke issues since I never had a habit of entering slalom racing with my cruiser
     
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  7. dylanray

    dylanray

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    All excellent feedback on this, thank you all for the input.

    I'm going to give you guys a call a little later this week about some sliders and maybe we cam chat a little more about how to get these spring eyes leveled out a better even if I need to do a through frame shackle hanger.
     
  8. dylanray

    dylanray

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    I didn't mind they way it drove with the current SR even though the springs eyes were not level. When I go SOA I only imagine it will drive better since I will be correcting the bad castor.