I just finished building a rear 4 link. I used the Petersons article as a guide,and got it to fit building it to the letter,(uppers 40%of lowers,uppers at 40*) .


My problem is the lower links, they said to make the frame mount
40% as wide as the axle mount. this is how i did it.

it works very good on and off road,but with the links at this angle i had to bump stop very tight to make this work.

my question is would it hurt handling or performance any if i moved the crossmember mount closer together,say an inch or so.

any help would be great.
btw i have read every thing i could find about 4 link on this site allready. :flipoff2:

i know one of you smart guys on this board can answer this small question please

90% chance it'll be ok,

give some details:

pics would be good,

Length of links

type / size of heims / joints / bushings?


Don't take an article in a 4x rag as gospel, you can probably move something 1" off their "perfect" number and have no ill effect.

Better concern is what's your AS? how high is your CG and roll center?

ok got measuremants,sorry no pics,no red star & too much junk in the way (gas tank,ect).


Links
lower- 37"
upper- 26"
vert. sep.
front- 5 1/2"
rear- 11"
horiz. sep.
upper
front- 20 1/2"
rear- 4 1/2"
lower
front 16 1/2"
rear 37 1/4"
shock up travel 3 1/4" unloaded
don't remember total travel





this is on a samurai with D44's & 35's.

yes i realise it is not gospel but reading this board has told me that moving things a small amount can make big changes.:eek:

i really dont think that an inch will hurt it at all. but then again i stick with leafs...

Originally posted by foley
Better concern is what's your AS? how high is your CG and roll center?

Thats what I was thinking too. If the links are too long or too short, and the CG is off it will make things "different" for lack of better terms.

Why make the uppers shorter than the lowers, other than for space concerns?

Seems backwards to me, but Im always looking for input.

I read everything I could and bought every magazine I could find with 4-link pictures before starting my 4-link project. From your description it's hard to tell what you're looking to do. I'm not a fan of the double triangulated links setup. My 4-link used the upper links to locate the axle side to side and the lower (longer) links to locate the axle front to rear. The most important thing is to keep the links as parallel as possible so they move in the same arch and don't bind up. My link setup started as an Avalanche kit but I cut it up and redesigned it. The lower links were moved outside the frame (they were made to go inside the frame along with the upper links). Not a good setup IMO.
Pictures of my 4-link are below. Click the link for pics. Very stable on the street with 40" of articulation off-road. No binding and no extra axle stops were needed.
swon

yes the uppers are shorter mainly because of space, but this also the way the mag said to do it cant rember why but on one of the
4 link threads on here it gives a reason

CG 40"? upper bell housing bolt
Wheel base 84"
as far as AS, roll center i haven't put this on paper, i am much better at measuring, cutting, welding than drawing and this stuff seems hard to figure out with out the paper part.

i can tell you from seat of the pants that this thing handles better than new. does have a little body lean but besides that it is tight.

from what i have read on here, not double triangulating the links
would cause too much rear steer.

Originally posted by rocksam
yes the uppers are shorter mainly because of space, but this also the way the mag said to do it cant rember why but on one of the
4 link threads on here it gives a reason

CG 40"? upper bell housing bolt
Wheel base 84"
as far as AS, roll center i haven't put this on paper, i am much better at measuring, cutting, welding than drawing and this stuff seems hard to figure out with out the paper part.

i can tell you from seat of the pants that this thing handles better than new. does have a little body lean but besides that it is tight.

from what i have read on here, not double triangulating the links
would cause too much rear steer.

with your single triangulated link, your roll center height is the height of the two upper link axle mounts.

with your single triangulated link, your roll center height is the height of the two upper link axle mounts.


mine is double trianglulated.

horiz. sep.
upper
front- 20 1/2" (frame)
rear- 4 1/2" (axle)
lower
front 16 1/2" (frame)
rear 37 1/4" (axle)

i could also move the lower axle mounts to fix my clearance prob.(less angle no the lower links)

Well I'm running a wishbone 3 link on my sami buggy and the lowers are 38 inches long and the upper is about 40 inches long so I don't know why you are having locating problems. My uppers go right up next to the t-case. Double triangulation on a sami is difficult as the t-case is off centered but my lowers triangulate right up next to the drive shaft. If you don't triangulate the lowers in as much as you can then as the rear articulates and one side droops it also starts pushing up on the frame rail which will want to push your vehicle over on it's side. I have 40 inches of seperation of the lowers at the axle and 14 at the t-case/frame/ There is 22 inches of seperation at the frame for the upper and obbiosly comes to a single point at the axle. I have about 8 inches of seperation upper from lowers at the axle and 4 inches at the frame. Lower links are mounted on top the axle at the very ends. I'm using toyota axles. Lower links sit about a 1 degree incline and the uppers are at 0 degrees. This leaves me no axle wrap, very little rear steer, about 100% antisquat, thus the vehicle lifts very little. It handles the way it is supposed to and I'm happy with it. Hope that helps ya a little. I'll post some pics Monday.

Originally posted by swon
I'm not a fan of the double triangulated links setup. My 4-link used the upper links to locate the axle side to side and the lower (longer) links to locate the axle front to rear.

The most important thing is to keep the links as parallel as possible so they move in the same arch and don't bind up.

My link setup started as an Avalanche kit but I cut it up and redesigned it. The lower links were moved outside the frame (they were made to go inside the frame along with the upper links). Not a good setup IMO.


It sure would be nice if you explained WHY you did or think the things you do...


Your first sentence- in a dual-triangulated setup the lowers still locate the axle front to rear. The difference is that they transmit that force through a crossmember instead of directly to the frame rails. Solution: build a strong crossmember.

The second sentence makes no sense at all. They don't need to be parallel. They can be, but they don't need to. In fact, if you really read through everything like you said you did, a lot of the guys on this board recommend NOT making them parallel. ;)

Third sentance- outboarding your links gives you more potential for rear steer, especially since you decided not to go with the dual-triangulated setup. This is assuming your lower links are angled and/or you have more droop than compression.


As for the original question in this thread- I agree that moving them an inch isn't going to change much. I don't understand your clearance issues from your description though.

thanks for the replys :D the clearance thing is a samurai thing you wouldn't understand:flipoff2: it is a mount bolt for the transfercase that the link runs under.


ECF thanks . from what you said yours is a buggy. mine is still full body stock fuel tank. my front links mount on a crossmember behind the tcase,about the same as the drive shaft yoke.