For those that were involved in the pinion angle discussion or anyone that cares.
The angles etc I use here are just for discussion not "GO BY" numbers.
The angles etc I use here are NOT compensating for anything...uneven lift, ride height.
I'm only doing this to clear up (hopefully) the specific discussion we had this weekend.
My impala sat with the tailshaft down approx 2 degrees.
(Can you change this? yes, slightly, BUT...Overlooking the ability to shim it at the support etc....we move on)
The rear was adjustable, so the question came up....where do you want it.
The observation was made that every pinion witnessed tips downward.
SO...what should we do?
You want the 2 angles of the fore & aft u-joints to be equal.
If the tailshaft was 2 degrees down, you'd want the pinion 2 degrees up....BUT
THAT disagrees with the observation.
Not really....if theyre BOTH 2 degrees then the pinion angle = ZERO (thats NOT what you want)
Now you want to SET your pinion angle
This is where the observation comes to light.
Here's the Recommended Pinion angles (by the pinion angle guys not me)
Full Solid Mount Suspension = Neg 1 to Neg 1.5 degrees
Half Solid / Half Poly = Neg 1.5 to Neg 2.5 degrees
Full Poly = Neg 2.5 to Neg 3.5
Full Rubber = Neg 3 to Neg 4.5
With my pinion 2 degrees up I have to adjust downward Neg 2.5 to Neg 3.5 (Full Poly) to get the proper pinion angle
THAT points my pinion down (Neg 0.5 to Neg 1.5) as expected.
I THINK I've made this easier to understand....Hopefully I'm right here. I'm pretty confident.
Bottom line is, you want to avoid Positive pinion angle and want as close to ZERO as possible on full launch.
Yes, we did need Glenn there
....hopefully if I'm wrong above he'll post