Front 4 link/coil suspension. Anyone done it ?

[JCole]

I don't like the way my leaf springs are on my project. The geometry has a lot of things against it and I think it would be easier to start over and go with something a little more heavy duty, with less flex.

There is lots of info on pirate4x4 about setting up a rockwell with a coil/4-link type suspension, however all of the info seems to be for low speed rock crawler type setups. This vehicle is going to be looking at atleast a 5000lb payload on occasion, and I need a setup that wont buckle if I happen to need to bounce the front over a log or something.

Was thinking of using unimog coils, or something similar in dimension/spring rate. The front end weights should be similar. The frame-side brackets would offer a considerable drop from the frame, slightly below the transfer case cage, to get the arms as parallel to the ground as possible without a super long arm.

Was thinking parallel arms with a track bar/panhard bar for lateral stability.

Here are some pics of the current leaf spring mock-up as it sits now. Any ideas would be appreciated.


IMG_20110606_161750 by ColeSpeed, on Flickr


IMG_20110606_161811 by ColeSpeed, on Flickr

No comments on the drag link please. LOL it's just a temp piece so that it can be driven around the shop. Has anyone doing lifts on these ever raised or fabricated a larger steering arm at the axle side ? The way it sits now, I can see some considerable bump-steer scenarios happening. I'm using a HINO steering box, and I will be having a longer pitman arm made to decrease the drag link angle, but I'd like to raise the axle side at the same time, so that I won't take a huge loss on leverage.

 

[JCole]

FYI the current springs are re-arced Dodge 1-ton springs.

 

[powerhouseduece]

Why not 4-link and airbags? By the time you set up the links and coil buckets, you can just run bags and get a better ride.

 

[JCole]

Why not 4-link and airbags? By the time you set up the links and coil buckets, you can just run bags and get a better ride.

That's also a consideration. The problem is that if I do airbags, I will REALLY want to do an auto-level system like my rigs have. I have no idea how to set that up. Also, are air bags available that will allow for some decent travel ?

 

[Billy Bobbed]

Airbags.
http://www.steelsoldiers.com/deuce-modification-hot-rodding/65764-full-air-ride-crew-cab.html

 

[JCole]

Airbags.
http://www.steelsoldiers.com/deuce-modification-hot-rodding/65764-full-air-ride-crew-cab.html

LoL could you post a more relevant thread ? That's exactly what I needed.

 

[powerhouseduece]

Its all about how you set it up. Watch the vid, he has his bags mounted to his upper links so he could get more travel. (his build is on Pirate)

[media]http://www.youtube.com/watch?v=3olWxhjBXo8[/media]

 

[RavageRitual]

off topic: what is that in your avatar and can we see more pics of it?

 

[JCole]

That's my project. Its a Hino FB Turbo cab/drivetrain mated with m35a2 running gear. Kind of the best of both worlds. Modern civilian cabover with a military duty chassis. Its the length of a crew cab long box pickup but has 14' of rear deck without any overhang.

 

[Flat Black]

other than sitting WAY too high for my tastes, i love the idea of 4x4 and 6x6 cabovers, especially since they dont exist in the US with VERY few exceptions.

Cabovers such as Mitsubishi Fuso, Isuzu, Hino and Iveco are available in the rest of the world with four and six wheel drive on several platforms.

 

[JCole]

other than sitting WAY too high for my tastes, i love the idea of 4x4 and 6x6 cabovers, especially since they dont exist in the US with VERY few exceptions.

Cabovers such as Mitsubishi Fuso, Isuzu, Hino and Iveco are available in the rest of the world with four and six wheel drive on several platforms.

Not actually very high. The photo angle is deceptive. All the weight other than the very light cab is Nat the top of the tires or below.

 

[H2duece]

YOu should open another post with some pics I am interested in what all you have done with the hino and what else you have planed!!

 

[Kohburn]

I've thought about doing a cabover on the deuce when i do the camper conversion. mostly to gain the additional rear space but also for the more modern features of the cab interior.

would be interested in more photos of that.

 

[nk14zp]

YOu should open another post with some pics I am interested in what all you have done with the hino and what else you have planed!!

He has started a thread.
http://www.steelsoldiers.com/deuce-...d-some-advice-regarding-shocks-bumpstops.html

 

[H2duece]

heck how did i miss it LOL i am eat popcorn and waiting to see what happens on both post LOL

 

[JCole]

I'll post an actual build thread once its back on the ground rolling on its own power.

 

[Kohburn]

ran across this New Project: M35 6x6/Hino Hybrid (Yes, THAT one.) - The Something Awful Forums

not the way i expected it to be spliced together but it makes sense and was probably a lot easier.

 

[mudguppy]

what are you plans for the steering? (not sure if i missed that you're going hydro?)if you leave the pitman arm in front of the axle and put your control links behind it you will have dangerous bump steer.

put the control links forward of the axle - it will ride/drive clean and be bump-steer free...

edit:

the best example i can think of that uses controlling links in front of the axle and not behind the axle is the monster truck Bearfoot. i saw Bearfoot 11 perform in '94 and noted the suspension difference in the pits. all other modern monster trucks i've seen since (except one other) have utilized the more traditional 'trailing link' front suspension. i believe this is because the way it performs for freestyle and jumps.

in a leading link suspension, the axle moves in a rearward arc as it travels upward. this 'drags' the axle over a bump. in a trailing link system, the axle moves forward and must accelerate upward over the bump. this leads to 'popping' the front end up when a large bump (car) or berm is hit. at the show in '94, Bearfoot walked all over Gravedigger in the final round; Bearfoot floated over the obstacles and barely left the ground, not wasting time in the air. but 'Digger got the massive air, and therefore, was the crowd favorite.

a real-world example is the older Jeeps; it was a popular mod to do a shackle reversal up front to improve the ride. the spring shackle was in the front, and when moved to the rear, ride improved because it was the same as changing from a trailing link to leading link system.

for a deuce, a leading link setup would be ideal. especially if you intend to keep the steering arm and drag link longitudinally attached forward of the axle.



see Bearfoot images below found at Fred Shafer's site. also, check out the last picture: it's a head/head race w/ the two different suspension types, leading and trailing links. note how much lower Bearfoot is than Carolina Crusher coming out of the jump...

 

[robert c neth]

we just finished our new mud truck frame its 4 link with 5 ton military axles.i dont see why a 4 link wouldnt work on your truck.buy good quality hiem joints.we designed all our mounting brackets and had them made on a computerized plazma machine.since we supplied the steel this was pretty cheap .we also used 2x2 1/4 wall thickness tubing for the link bars since shipping and buying dom was real expensive.the front coils are from and f 350 and are huge.good luck on your project

 

[Flat Black]

correct me if I am wrong, but in a leaf sprung suspension with a fixed front and a shackle at the rear, ride height should show about 45* shackle angle. As the leaf flattens out and the tire comes up into the body, the shackle angle will travel towards the horizontal plane, thereby "pulling" the leaf and the axle back with it, causing the same problem mentioned above. This is always an issue when trying to "bump" over an obstacle off roading, as the tire is moving away as you are trying to climb. The ideal geometry would walk or push the tire forward as you try to climb, thereby assisting your ascent.