Hi,

I will be doing a Coil Suspension Conversion to my SJ-413 and wanted to know which all kits are available and their links. I searched a lot but could find only the following coil over kits:

#1: Rock Road Coil Over Kit : ~1500 USD

#2: TrailTough Trail Slayer Kit: ~4000 USD and required toyota axles.

Now, In India I HAVE to use stock axles as I will not be able to get Toyota axles. So, Is my choice limited  to Rocky Road kit? or are there some other options.

Also, is it worthwhile to DIY/Fabricate the parts of buy a kit and just weld it together. I wil have NO problem in welding but fabricating (without a real sample) is very tough.

So what are the options??

Also, since the kits would be for LHD Samurai's would there be issues in getting them fitted in RHD Samurais?

khan_sultan:

It's good to hear from you again.  Is this for the Spider?

What are you hoping to get out of this kit?  Just a better/softer road ride?

khan_sultan:

It's good to hear from you again.  Is this for the Spider?

What are you hoping to get out of this kit?  Just a better/softer road ride?

Well, I might sell my Spider and start off on a new project and that one would be Coil Over for sure. That reason would be softer ride + greater articulation. I think SPoA/Leaf Springs have limitations on ride quality/Articulation. And I say this with having used Composite Fiber leaf springs... They were supposed to be unbreakable, but I broke 3 sets of them :-(

If it's unbreakable then your just not trying hard enough. 

Do you have access to DOM tubing?  Drawn Over Mandrel?  If so I would say you should try making your own, you certainly have the skill looking over some of the other conversions.  I can give you the measurements I used to make the 4 link on the rear.  The coils are going to be the hardest part.

The biggest limitation I can think of is getting the joins for the extra articulation.  If necessary I can order some for you along with the bungs to allow mounting them in the tubing and ship everything over for you.

Do you have access to DOM tubing?  Drawn Over Mandrel? 

Yes, I have access to DOM Tubing. Any spec/rating/OD/ID can be easily sourced in India.

I can give you the measurements I used to make the 4 link on the rear. 

YES..!!!! Thanks a lot my friend. That's exactly the help I would need. The measurements.

The coils are going to be the hardest part.

I agree, but I have access to a factory that produces coil springs for various vehicles and can give me a set of springs if I give the specs to them. So would need help in Specs and fabricating them would be easy here.

The biggest limitation I can think of is getting the joins for the extra articulation. 

Yes, if the joints are not of proper type, the whole setup can go waste. I plan to use the BEST joints. Again, Would need your help in specs and will try and see if they are available in India

If necessary I can order some for you along with the bungs to allow mounting them in the tubing and ship everything over for you.

What can I say..!!!! MANY THANKS..!!! If required, i will take up that offer. Let me check and see what can be sourced locally.

But yes, Would need your expert help on the measurements. I will share with you the measurements of my Samurai Chassis so that it gives you an idea of the difference between the US Spec Samurai & Indian Samurai

Cheers,

How much lift are you going for?

For my lift I had the length of the lower links at 35", upper links at 26.75".   We will probably want to change that a bit as you have an SJ-413 which I believe has a 3" wider frame.   You can check out the build BRD HNTR and I did over at http://zukiworld.com/forum/build-diaries-how-to-diy/sj-410-rear-4-link-build/ to see how we did it.

We will need a few measurements to get started. 

What is the width between your frame rails? 

How wide is your frame?

How high is the frame off of the ground?

How high is it to the center-line of the axle?

A really good set of articles to read to help get started are available on-line:
http://www.4wheeloffroad.com/techarticles/suspension/131_0306_four_link_suspension_part_1/index.html
http://www.4wheeloffroad.com/techarticles/suspension/131_0307_four_link_suspension_part_2/index.html

Do you have a copy of Microsoft Excel?  If so I can send you the 4-link calculator BRD HNTR and I have used to run numbers through.

You have given me a fresh idea of going in for a 4-Link for just the rear and keep the front in SPoA setup. What would be the advantage of this? One thing I can think of is the added complexity of Coil Over in the front (with steering setup). Right?

Let me think & see. This (only for rear) can be done on my existing Samurai & I will have no need to buy another one :-)

How much lift are you going for?

6 - 7" of lift from stock. So, this would basically mean as high as it is right now. This is how it looks right now

For my lift I had the length of the lower links at 35", upper links at 26.75".   We will probably want to change that a bit as you have an SJ-413 which I believe has a 3" wider frame.   

yes, the chassis dimensions are different & also the Wheel base is different.

You can check out the build BRD HNTR and I did over at http://zukiworld.com/forum/build-diaries-how-to-diy/sj-410-rear-4-link-build/ to see how we did it.

Wow.!!! This is great. A repository of valuable information. This will help me a lot. One thing I noticed is that you have used regular bushing at the axle end and jonny joints at frame end. Why? What if we have JJ at both ends? Any pro's cons?

We will need a few measurements to get started. 

I will share the x/y/z dimensions for upper/lower link for both the frame & axle ends.

A really good set of articles to read to help get started are available on-line:
http://www.4wheeloffroad.com/techarticles/suspension/131_0306_four_link_suspension_part_1/index.html
http://www.4wheeloffroad.com/techarticles/suspension/131_0307_four_link_suspension_part_2/index.html

Do you have a copy of Microsoft Excel?  If so I can send you the 4-link calculator BRD HNTR and I have used to run numbers through.

Thanks. I had read these 2 articles loooooong back and need to refresh my memory again. I have the calculator with me but would need help in interpreting the output numbers and various options.

Thanks again.. will post detailed questions as I get a bit more clarity.

For the springs:

- What load rating should one go for (rear axle). Would 150 lbs or 175 lbs? I would want a soft ride and would be having VERY VERY less load at the rear.

- Now in the picture below, what are the length & width measurements of the springs? I am assuming that the length of the spring will impact the lift one gets.

For the Joints:

- What is the thing marked with black arrow? What spec, size? I see in later pics that this is welded on to the DOM tubing.
- What spec/size is the joint?

For the arms/links

- When we say that the arm is 36" (for example) in length, are we calculating JUST the pipe length (Black arrow) OR does that include the length form eye to eye of the joints when they are welded on to the DOM tube (Red Arrow)?
- What is the spec of the DOM Tube? What OD/wall thickness is required for a bullet proof setup?

Cheers,

You have given me a fresh idea of going in for a 4-Link for just the rear and keep the front in SPoA setup. What would be the advantage of this? One thing I can think of is the added complexity of Coil Over in the front (with steering setup). Right?

The main reason we did this swap was I kept bending up my rear springs.  Originally we were going to build a traction bar.  After looking at the amount of work we decided to just go all the way and build a full 4-link.

The front is actually easier then the rear as far as design.  You need your lower two links, an upper link to keep the axle from rolling, then a track bar that is as close to even wit your steering arm in length and positioning as possible to keep the axle from shifting left or right.  Since you are using a track bar to keep your axle  from shifting left or right you don't have to worry about triangulation near as much as you do with a 4-link in the rear.

For the lower links a lot of people just put a Y on one or both sides.

6 - 7" of lift from stock. So, this would basically mean as high as it is right now. This is how it looks right now

So about the same amount that I am running in the rear.  I wanted to keep my rig lower as well.

yes, the chassis dimensions are different & also the Wheel base is different.

Yes, so you have a bit more room to play with.  Do you want to keep the lower links up on the side of the frame, as I did in order to keep your frame clearance as high as possible?  If so it makes things a bit harder due to your wider frame.  But still doable.

Wow.!!! This is great. A repository of valuable information. This will help me a lot. One thing I noticed is that you have used regular bushing at the axle end and jonny joints at frame end. Why? What if we have JJ at both ends? Any pro's cons?

I had a really good reason, JJs are expensive.    The main advantage of putting JJ on both sides is a bit more additional flex.  We were going for ride quality first so I decided to just put the JJ on one end.  We designed the system so we can always cut off the other end of the tube and put joints on if needed.

I will share the x/y/z dimensions for upper/lower link for both the frame & axle ends.

Thanks. I had read these 2 articles loooooong back and need to refresh my memory again. I have the calculator with me but would need help in interpreting the output numbers and various options.

BRD HNTR has probably spent more time looking over numbers then I have.  He just finished building a 4-link on the back of his Tracker project. 

For the springs:

- What load rating should one go for (rear axle). Would 150 lbs or 175 lbs? I would want a soft ride and would be having VERY VERY less load at the rear.

- Now in the picture below, what are the length & width measurements of the springs? I am assuming that the length of the spring will impact the lift one gets.

I used stock springs from the rear of a Geo Tracker.  Approximate 11" tall at 155lb's.   The ride is great, and it would be even better with your longer wheelbase.  I believe most people recommend going with 150-175 lb's in the back.

The springs are 3" wide.  On Project Trouble we switched to 2.5" wide springs and they seem like they will work just fine.  Since you have to make your own spring mounts I would go with whichever size you feel like.

For the Joints:

- What is the thing marked with black arrow? What spec, size? I see in later pics that this is welded on to the DOM tubing.
- What spec/size is the joint?

That is the bung, it allows the JJ to thread into the tubing without us having to weld on a nut or thread the tubing itself.  I believe those are the 1 3/4" JJ's with a 3/4" thread.

For the arms/links

- When we say that the arm is 36" (for example) in length, are we calculating JUST the pipe length (Black arrow) OR does that include the length form eye to eye of the joints when they are welded on to the DOM tube (Red Arrow)?
- What is the spec of the DOM Tube? What OD/wall thickness is required for a bullet proof setup?

Measurement is from eye to eye.  The DOM I am using is 1.5" with .120 wall thickness.  For the weight of a SJ-413 the 1.5" .120 is probably more then enough, but you can go to a 2" lower link if you want.  It won't hurt anything.  One of the reasons we used the 1.5 was that it matched the tubing bender dies we had so we could re-use the extra DOM.