Ok I just put a flip kit on my truck and I'm trying to get the pinion angle around -4*. I put the angle indicator on it today and the yoke was at 0* and the rear drive shaft was at about .5*. I thought about it too much and confused myself. What degree shims do I need to achieve the -4*. Thanx

 

If that 0.5* is the driveshaft pointing upward, you need a 4.5* shim

 

Drive Shaft Harmonics

Its got pictures too, so it helps me the most

 

Everyone has different definitions of pinion angle, confused the hell out of me. My final interpretation was that its the angle the pinion makes with the ground. So if you pinion is parallel to the ground then you need a 4* shim. Mine is about -1* and I have zero issues.

 

Not quite. The rear end doesnt care where the ground is, all it cares about is the angle the driveshaft is relative to it. If the dshaft is parallel to the ground, then you want the pinion -3* towards the ground (OP wants -4*). So if the dshaft is 0.5* upward towards the sky, then you need a shim to point the pinion 3+0.5* downward (0.5+4 for the OP), so a 3.5* (4.5*) shim.

 

Ok I I did some adjusting on my pinion angle today and got it negative but I think too much. No vibrations and it feels good too. But I measured again and this is what i came up with. Drive shaft is at 0* and differential is pointed down at 6.5*. So I just need to rotate my axle back up 2.5* to get my 4*? And the way it is now could that hurt anything? Thanx

 

Yes, 2.5* should put you back at -4, but if you dont have a lot of power -3 might be better.

Running too much of a negative angle is just as bad running too much of a positive angle.

 

What's a lot of power? Lol the answer seems to vary from person to person. I'm guessing ill be around 550-600 once I put my new turbo on and ill hit it with a 30-40 wet shot on track days.

 

I would shoot for around -3 then, 700+ I would say -4

 

Alright thanx