A few questions

I'm just trying to increase my knowledge, I'm not arguing with anyone.
I've heard that using fulltime 4WD with a lunchbox locker is badnews, but why? I mean I have a lunchbox, and if I slip the clutch it isn't receiving full power, just like if I was in fulltime. Also, how does the locker know what "full power" is?
Also, why is it better for the U-joint angles on the driveshaft to be the same? Wouldn't you just want each one to be as close to zero as possible?
Why is this
better?
Wouldn't
be the best? I understand they're for different DS joint setups, but why isn't the second one always the best? How does one U-joint know what the other one is doing?
Edit: unofficial thanks to Tom Woods for the images.

If those pictures are off of tom wood's site, which it looks like they are, they have a great explanation of this.

I'll give it my best shot here: A u-joint does not transmit a constant velocity when it is at any angle other than 0. At other angles, the transmitted velocity will actually fluctuate around the input velocity. IIRC it actually changes in a sinusoidal fashion. Because of this, in a non C.V./dual Cardian shaft the u-joints should be at the same angle when at ride height so that the velocity going into the yoke at the axle will be a constant velocity, not one that is changing constantly that would result in vibrations.

In a C.V./dual Cardian shaft, the fluctuating velocity is actually canceled out in the C.V. yoke part (the part that has the two u-joints next to each other). The yoke on the axle should be in line (it should have no angle in it) with the drive shaft so the final u-joint does not introduce a changing velocity.

Hope that helps. I know the write up on Tom wood's site says what I just said 100% better.

Chris

2000xjclassic said:

The yoke on the axle should be in line (it should have no angle in it) with the drive shaft so the final u-joint does not introduce a changing velocity.

Click to expand...

The pinion should have about 3 degrees less angle then the drive shaft to compensate for axle wrap from torque.