I have seen, from "big name" sources over the past few years on the net, contrary info on proper pinion angle setting; basically, some say to match it to the trans angle, while others say to lower the rear end a few more degrees than this.

I have even seen at least one saying to raise the rear end a few degrees, not lower it. I didn't keep a record of who said what, but trust me there are differing views.

My question is, what is the correct way to set the angle, and why? Is there more than one correct way, maybe for different applications?

I don't have to set any angles at the present, but I have been meaning to ask this question for a while. I'm sure others will also benefit from this info.

Regards, Paul

 

I'm in the process of fine tuning my setup. Maybe this link will help:

http://www.clubfte.com/users/jniolon...nephasing.html

 

Some say a little lower so the pinion angle will be closer to correct under load.

 

Here is the way I understand it and it works.

 

Hi paul ,

Pinion angle can be anything you want it to be (within the capabilities of the u-joints you are using) BUT the important thing is that the imaginary center line of the transmission and the imaginary center line of the rear end are the same.

When you accelerate or dump the clutch and the tires bite the rear end will try to turn up in the front, to offset this some folks put a 'down' angle in the pinion so as it twists it's coming up to parallel. If you have enough torque and enough tire bite you'll experience spring wrap as the rear end twists. Traction bars were designed to stop the wrap and transfer the torque to the frame instead of the spring... gives you a little lift on the front end and a weight transfer to the rear increasing traction.. You also have to consider the angle of your engine/transmission... if you're leveling your carb (if the intake has any angle built into it) and how everything works together...from the radiator/fan relationship all the way thru the rearend.

On a street vehicle I don't think you'll have a problem with wrap and you could set your pinion level or a little down with no harm. I think most will agree that 2-3° is usually about all that is necessary. If you're designing a race truck.... then forget everything I just said and listen to someone who knows something about drag racing and setting up a competion rearend.... it's a science itself.

if you're not confused enough yet ???? try this

driveline phasing

hope it helped...

john

 

Well, I tried to add the picture but as you can tell it is beyond my capabilities.