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Instant Center position of Three Link for Off-road use.

Instant Center position of Three Link for Off-road use.

Instant Center position of Three Link for Off-road use.

(OP)
Hi,

What I have is a Jeep with a lifted suspension and stock control arm mounting points.  It is a three link with a panhard bar.  Suspension works great for most everything except when trying to climb a ledge.  Due to the Factory designed short arm and mounting points the front suspension tends to roll under the vehicle rather then drive up the ledge.

The best way to fix this would be longer links at flatter angles to reduce the IC location.  However I don't have the time or resources to do that at this time and will design a new system with the new drivetrain.

Due to the requirements of the system the IC are always higher then the axle centerline so we tend to do then next best things and put it as far behind the truck we can.  

So in playing with my current suspension points I found my current IC location.  If I move the lower axle end mounting point up 0.5-1"  I can get the IC to move back farther but it also moves up higher.  Would this help the tendency of the axle to roll end the vehicle?  While the IC is moved back quite a ways farther it's also moved up which I'm not sure if a good thing.  

If I move it up farther (2-3") then the IC moves to the front of the axle.  

What I'm trying to determine is if there is any solution of adjusting the lower control arm point and help reduce this condition.  If not I'll deal with it until the new drivetrain and suspension goes in.  

I can post up my ~locations when I get home this evening.   

RE: Instant Center position of Three Link for Off-road use.

(OP)
Here are some rough numbers:

CG 28"
Wheelbase 101"

Setup as is
IC X axis: 47.38"
IC Z axis: 135.56"
~AS%: 129

Raised Lower Axle Mount 0.75"
IC X axis: 116.29"
IC Z axis: 491.63"
~AS%: 87

Raised Lower Axle Mount 0.9"
IC X axis: 254.13"
IC Z axis: 1203.75"
~AS%: 78

Raised Lower Axle Mount 1.25"
IC X axis: -67.48"
IC Z axis: 457.88"
~AS%: 54

Raised Lower Axle Mount 1.5"
IC X axis: -21.54"
IC Z axis: 220.50"
~AS%: 36

So it seems I could raise the axle lower mount up some ad reduce the AS quite a bit.  I don't think I would want to raise it past 2" as the vertical separation on the axle end will go under 6".   

Comments would be appreciated.   

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