Rear suspensions angles

[Hydros]

Ok here's what I've picked up so far. I was looking at the rear trailing arms and noticed some damaged.

(INSERT PIC HERE)

I noticed that when the back is lifted to the Max (without shocks or chains), the upper trailing arms will hit the frame.

Because of the geometry, It appears that when topped off the rear end (differential)  will move closer to the front of the car.  This is desirable, as it helps to produce the teeter-totter effect. But as the rear end move closer to the front, the drive shaft digs into the transmission. Also this produces a bad angle of the drive shaft.

I was trying the think of a way that would allow the rear end to keep it's same angle, and as the body get higher.

This is what I've come up with. It's just an idea, and need plenty of testing.

The green tacks are the contacts points of the forward mounts of the trailing arms on our make believe car.

See the red vertical line, that's a reference point that follows the position and angle of the rear end.

[Hydros]

Here is a example of the back lifted, note the bad angle of the drive shaft and differential, Also, see how the rear end has moved away from the reference point and toward the front.

I have since learned that the way to overcome this is to use a longer upper arm.

Looking at his pic (I hop to get another pic here soon) imagine that the upper arm is loner and is pushing back the upper part of our differential.

[Hydros]

Now here is something I came up with.
Evertything is straight, just like in the first PIC.

[Hydros]

As you see here, as the body goes up, the differential, and drive shaft keeps the same reference point and the angle is much better.

The problem here is that the rear tires are not longer closer to the front of the car. It appears that the Teeter-tooter effect is gone.

The upper arms do get longer as the body goes up = good Because the angles and positions are good.

Now if I could find a way to make the differential keep a good angle and at the same time, move toward the front more.

Anyways, here are just some thoughs I had. Maybe I'll just copy everyone else for now, which I've heard was to use slip joints and the longer upper arms.  I did note on LIL that someone suggested to move the contact points. I got to get clear on what they mean, so I'll get back with more details later.

[Guest]

i just notched my frame and ground the connection between the pumpkin and driveshaft, thats was good enough for a 12" lift from ground zero.

the driveshaft does slip forward,but when is it enough to become a problem?

By the way, I think telescopic driveshafts with supports are probably gonna stick with the big hoppers

[Lifted Monte Carlo]

I'ved heard of a 4wd company that makes high angle drvshfts for rock crawlers and stuff like that.  Maybe couple the ideas, high angle d/s with the telescoping ability!!??

[Guest_LowriderUK]

Although it appears to work on paper, your proposal is not feasable.

Because there is four pivot points on the upper arm, there is no rigid fixing between the pivot point on the axle and the pivot point on the frame. This will allow the top arm to move around at free will and flop about, so when driving forwards, the axle will want to tip backward as the four pivots on the upper arms move to allow the arm to be at its longest stretch.