Setting up driveline angles

[hessdawg]

Engine and tranny ar in, and now I'm trying to set up my driveline angles
I'm welding in a 4 link
The car is up on jack stands and looks level.
The reading on the angle finder shows the flowing
Frame 1.15 up
Body and the bottom or the rocker .40 up
Transmission output housing 2.55 down


Do I need to add subtract the 1.15 degrees that the frame is up From the 2.55 that the trans is down?


That would leave the trans at 1.40 degrees down
Which means the rear end needs to be set at 1.40 degrees up correct?

[andrewb70]

Is "up" in the front or in the rear...need better definitions...LOL

Andrew

[hessdawg]

Up means pointing up the front of the car is pointing up 1.15 degrees
And the rear of the transmission is pointing down 2.55 degrees

So if the frame was level at 0 degrees then the transmission should only point down 1.40 degrees .
If that is correct the rear end yoke should be equal and opposite. So the rear end should point up
1.40 degrees

Am I correct?

[andrewb70]

The angle of the frame is totally irrelevant. You're also missing a key component: the driveshaft.

What is important are the front and rear operating angles, which is the angle between the transmission output shaft and the driveshaft and the pinion shaft and the driveshaft. The front and rear operating angles need to be equal, opposite, and as small as possible without being zero.

Andrew

[hessdawg]

Thanks for the reply Andrew

Maybe I'm over thinking it

But let's say the frame is on jack stands and the nose is up 3 degrees higher than the rear end wouldn't
The output of the transmission be 3 degrees down ? Everything that I've read to have at least 1 degree but no more than 3 degrees working angle
http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

[andrewb70]

Thanks for the reply Andrew

Maybe I'm over thinking it

But let's say the frame is on jack stands and the nose is up 3 degrees higher than the rear end wouldn't
The output of the transmission be 3 degrees down ? Everything that I've read to have at least 1 degree but no more than 3 degrees working angle
http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

Again, the angle of the frame is completely irrelevant. Imagine a car driving up a steep hill. The frame might be at a 45 degree angle, but the operating angles don't change.

Even in the link that you posted, they measure the angle of the driveshaft. In their example, they want 3 degrees up on the engine and the driveshaft at 1 degree up. This will give you a 2 degree operating angle in the front. These measurements are irrespective of the angle of the frame. If the car is positioned at 10 degrees up, now the transmission angle will change to 13 degrees and the driveshaft to 11, but in the end you still have a 2 degree operating angle. Clear as mud? LOL

Andrew

[hessdawg]

That makes since
I'll install the driveshaft and see where I'm at