Driveline Vibration

[Keith Seymore]

Originally Posted by fixit-p

Drive line and pinion angles are not the same, dropping does improve driveline angle but a 5" drop w/o a 2" lowering block changes the pinion angle ~5.6* and a 3" drop with a 2" lowering block (5" total drop) changes the pinion angle ~ 3.3*. Assuming the pinion angle was perfect before the drop both of the above changes puts it out of spec (IMO). While it is apart would be a good time to at least verify your angles a cheapo angle finder would work for this.
All angles were calculated on cad layout with real word dimensions.

Are you accounting for rear axle housing rotation as the suspension travels, based on it's instant center location? Or just translating the axle up/down the desired amount?

Not throwing stones; a sincere question in the hopes of gaining understanding...

btw -I used to do this with masking tape lines spread out on the garage floor. Your way is better

K