Varg In Jeep's Clothing

Be carfull when you will set-up the bump stop. You need to set it at full flex, not when dropping the suspension on both side. You're tire when a full flex will get higher in the fender than when you're dropping the suspension on both side. When you flex the bump stop on the up traver side will act just like a pivot point, so even if suspension sit on the bump stop tire can still get higher in the fender because the other side is getting down. Here a picture that may help to understand (if you arent yet).

for my jeep i can put my hand between tire and fender but no more.

Also you don't need so much up travel, on my jeep i got 3 inch of up travel front and rear. You need way more down traver than up.

For the coil spring, i would suggest to use the cherookee one. I run some front Tj's 4 inch coil spring on front axle and oem coil for the rear. The ride quality is awsome.






Here's a picture of how i mount my coil spring on the front axle. Cherooke and tj on the upper part have the last loop with a smaller diameter than the rest of the coil, using poly bump stop i center the coil on the coil bucket. For the bottom i just fab a cylinder that goes inside the coil so it can move and always stay in the center. This way you won't need to attach the bottom of the coil. Also another avantages is the fact when you flex you don't have a too long bump stop that will get in touch with the coil spring. On jeep tj when folk's put 4 inch coil they just put a spacer on the bump stop and the problem occur.

 

I'm planning on using 4" rubber bumpstops between the frame and axle. I got in the habit years ago to build with clearances as if there will be no bumpstops. I'm not exactly easy on stuff. I have a tendency to put a substantial amount of air under my tires while laughing maniacally, and I don't like surprises when I come back to earth. I don't like putting faith in a block of rubber keeping me [x-amount] of distance from metal-on-metal contact. With enough force, I have to assume they will compress to near-zero.

Johneyboy, thanks for the heads up. With the 4" bumpstops, even at full flex (with the limited travel of the smallish stock Cherokee springs) I'm estimating the tire ending up in the same place as in the pic at full stuff. If there is a little rubbing, I won't be too upset. Flatty fenders are pretty stout. Keeping this thing low-slung is more important to me than wheel travel. I have another jeep for the hardcore stuff.

I had a "eureka!" moment yesterday, and now I'm in the middle of a semi-dramatic design change that will really change my initial plans for steering, shock, and track bar locations. Stay tuned.

Teaser: the radius arms are coming back out and getting modified.

 

I totaly agree on what you said, i don't want to impose thing but just make sure you now those thing. When i did my first coil spring set-up i did a lot of try and error , i was doing something custom just as you, and when i begin in this, i didn't have any experience in modification (welding, cutting, designing).
I still have to do some improve on my coil spring set-up. I want to lower this thing using some flat fender on front and make a custom round shape for the rear fender.


You're doing a great job out there, and having the knowledge you have my rig would have look way different.

For the wheel travel, don't forget that coil spring don't hold the axle on down travel just like leaf does, i will go down as much as you have shock travel or limiting strapp.

 

You sure do know how to set the hook, with a teaser like that...

Will be watching...

 

Ok. So I modified the radius arms to accept a behind-the-axle-mounted tie rod,



And I rebuilt the steering arms to accept said tie rod.





Now it will open up more room so I can mount the track bar and sway bar in front of the axle, and I'll also have room for the shocks. I had been planning on mounting them inside the coils because they wouldn't have fit anywhere else. Here is everything zip-tied in place. I'll need to do one heck of a precision bend-job on the tie rod to get it to fit back there and not hit the 3rd member or oil pan throughout its sweep. Frame will get notched.

 

....but they're really strong zip ties.

 

I'll let the photos speak for now; I need to get to bed. Tie rod and front driveshaft are fit.

 

Looks awesome!

 

Thanks Chris.

My conclusion is that this tie rod is chromoly tubing. I've built about 7 cages with this bender, and I never had an issue. This little 1 1/4" tubing completely messed it up. It almost folded. I thought for sure something was going to let loose. I even pulled the truck out of the shop. I didn't want to have to explain how a piece of tubing ended up through my wife's truck's bed side.

A very pleasant surprise was to see the center pivot of the front driveshaft fell almost perfectly in line with the pivot point for the radius arms. So throughout the suspension's travel, the spline will have virtually zero extension/collapse.

I'm up in the air about what direction to go next. The frame horns are going to need rebuilt with a steering box mount incorporated, and I sorta want that done before I start building track bar and coil spring mounts. But I also want my track bar mounted before I mount my steering box so I know how high to mount it and how high my frame horns need to be. Hmmmm. I gues some temporary mounts are in order.

 

Dang bro! You got a big hole in your frame!



You know it's getting serious when you have to break out wood products to make templates.



Here is full stuff, about 1" past where the bump stop should ever, ever allow it to go.
Full lock left, tie rod just touches frame notch and 3rd member.



Full lock right, tie rod just touches crank pulley - or edge of oil pan, depending how the tie rod is twisted in the TREs. It's as good as I'm going to get it. Driver's side has no clearance issues.

 

How did you cut that nice circle in the frame rail? whats the larger radius on the MDF for?

 

I just held the end of the pipe up to the frame where I wanted it, marked it with soap stone, cut it with a cutoff disk on a grinder, then ground into the line with a grinder. It took one trial and a 1/4" redo to get it in the right spot.

The MDF: I'm keeping the frame height at 4 1/2" up and over the notch. I'll cut the MDF to make a template for cutting the side plates, and to form the top strap around.

 

You're better with a grinder than I am.

I figured that was what the MDF was for. Pattern.

Looks killer.

 

I skipped over a certain step that some might find useful in the future. This was back when I built the steering arms for the behind-the-axle tie rod.

One of the important aspects of steering geometry is called the Ackerman angle. When you steer, all four tires are traveling in a different arc around an imaginary point. I won't get too detailed, but your front tires need to steer at different rates, with the inside tire turning sharper than your outside tire. This is achieved by the placement of the tie rod end in relation to the pivot point of the knuckle.

When you put axles from a longer-wheelbased vehicle in a short jeep, the Ackerman angle is way off, since the angle is directly relative to wheelbase.



The easiest way to set it up when building from scratch is to pull a string from the knuckle pivot centerline to the center of the rear axle.



Roughly...


Then I ground bevels on the arms and welded them in place.

 

Inside will get boxed when I do the rest of the frame.

 

I fully agree with engineering your steering so it works as intended. Ackerman is often overlooked. Are you playing with caster angle in conjunction with Ackerman? Caster is greatly affected as Ackerman is increased on the inside wheel while steering near the limit, and if properly set up, can really enhance maneuverability and tighter turning radius.
You can end up with the front tires angling like a road-grade on tight turns, and a steering wheel that returns to center that will break your wrist.
I was also wondering how your steering arms suddenly sprouted to the rear! You don't worry about welds breaking on critical components like steering arms?
I love to watch your creative ways to re-invent the wheel!
-Donny

 

Awesome work and thank you for explaining your fabrication choices!

 

Thanks guys. Unfortunately, I've got 3 "real" jobs lined up over the next few months, so this might come to a screeching halt again one of these days. On the plus side, I can soon stop borrowing money out of my kids' piggy banks for grinding discs and dust masks.

I'm really not concerned about the strength of these arms. These are aftermarket Trail Gear arms that are massive chunks of cast steel. Welding cast steel is really not much different than any other mild steel, but I preheated them just to be sure, and I also kept the overall temp within check to prevent the temper of the hardened kingpin from being affected. There is literally over 3 square inches of weld on each arm on 2 planes. It would need to be one catastrophic hit to break. And even if it did break, with it being the tie rod (as opposed to the drag link), I would only lose steering in the DS wheel. The pass side would still be attached to the drag link on the front arm.

There is a "5th stud" mod that a lot of Toyota guys do to their knuckles to strengthen the arm:knuckle attachment. If I start to worry about these, I'll do that mod as a failsafe when I get to the point of making the axle roadworthy. Something like this, but I'd run my plate up into my new arm for a positive connection to the mild steel, not just to the cast stuff.

I will only have my radius arm mounts tack welded to the axle until the very end, just in case I have to modify the caster based on ride hight. I'll get back to you on that in 5-10 years when I actually have this completed.

 

As always, I am impressed! When looking at your fab work it's evident that you have a lot of Volvo work in your past. It looks and has a Volvoesque vibe! Beautiful and strong work!