4 Link front suspension SFA
#1
4 Link front suspension SFA
quick and prolly nooby question...
but if you 4 linked a front axle under say my truck, could you get away with no track bar? ive heard some mention about this but was curious.
if i used like a jonny joint and put enough angle on the upper links it shouldnt allow the axle to move side to side right?
how would that effect steering? would it be road worthy still?
but if you 4 linked a front axle under say my truck, could you get away with no track bar? ive heard some mention about this but was curious.
if i used like a jonny joint and put enough angle on the upper links it shouldnt allow the axle to move side to side right?
how would that effect steering? would it be road worthy still?
#2
a double-triangulated 4-link will be constrained enough in the lateral directions that you won't need a trac-bar or panhard bar. I can't remember the last time I saw a streetable vehicle with a 4link in the front. I think our Rangers would run into problems with oil-pan clearance too with the 4-link suspension.
#3
you can get away with no trac bar on a triangulated 4 link.. atleast from what I understand. You will get some bump steer. As for whether it would be road worthy...?? I dunno really..
providing your keeping the draglink.
"The axle will droop perfectly centered, and as the drag link droops, it'll swing in an arc around the pitman arm, becoming angled (and horizontally shorter, but vertically longer)"
I actually just read ^^ that this morning..
basically if your draglink is level with the ground and your running a conventional/mechanical steering (tie rod knuckle to knuckle, no hydro,draglink) you will have tolerable bumpsteer issue at highway speeds, no worse than someone running leafs up front.
as I understand it this is compensated for by using full hydro steering.. but thats not street legal so not road worthy.. I hope this helped and didn't just confuse everyone..
providing your keeping the draglink.
"The axle will droop perfectly centered, and as the drag link droops, it'll swing in an arc around the pitman arm, becoming angled (and horizontally shorter, but vertically longer)"
I actually just read ^^ that this morning..
basically if your draglink is level with the ground and your running a conventional/mechanical steering (tie rod knuckle to knuckle, no hydro,draglink) you will have tolerable bumpsteer issue at highway speeds, no worse than someone running leafs up front.
as I understand it this is compensated for by using full hydro steering.. but thats not street legal so not road worthy.. I hope this helped and didn't just confuse everyone..
Last edited by icb12; 03-20-2007 at 11:40 PM.
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Originally Posted by lifted97ranger
true.........you can try it without and then if you need it put 1 in....
On a 4 link there are two main types. Triangulated and Parallel.
First Trigangulated. With this type of 4 link the angle of the links is what centers the axle. This is why no panhard is needed. It is Rule of thumb that at least 45* of triangulation is needed for this. That means you ad up the angle off the frame of the links. So if your top links are angled 22.5*, and your lowers are also 22.5*, then you will be fine. There are some guys who run less then 45*, but most are trail rigs. You can not run a panhard on this type of suspension as it will bind. Since the panhard will try to create an arc in the X direction and the suspension its self wants to arc in the Y, it will bind. This creates problems with steering, since the draglink is practically a panhard connected to the knuckles. So through out compression and extension of the suspension the draglink is turning the tires with out your input.
Now Parallel. The show truck you posted has a parallel 4 link. This is when there is very little to no triangulation in the links. They should be almost parallel. (think XJ and TJ) they both use parallel 4 links with a panhard. Since there is not enough angle in the links to locate the axle, the panhard is needed to center it. This is the setup you should go with for both clearance purposes and from a steering aspect, since manual link steering will not have adverse affects with this.
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