jet_wrnch
Active Member
What should my pinion angle be? Just moved my springs in and I'm try to set up the rear end. Is it 8 or 9 degrees and what is the best way to find it?
what pinion angle?
- Thread starter jet_wrnch
- Start date
-
Hold a 1/2 inch drive socket up against the bearing on the U joint (use one just small enough to fit without wiggling) with the drive shaft rotated so it is facing down. If the car is level you can just hold the angle finder against it. Then measure the angle of the drive shaft. Actually it doesn't matter if the car is level, just subtract one from the other. It is the relationship between the driveshaft and the rear and the transmission that you are measuring.
earthmover
in the tire smoke
i think its 5 to 7 i had my rear set at 6 in my duster....mike
71beater
Well-Known Member
I was always under the impression that pinion angle is referring to the diffrence or angle between the front and rear yokes.Stock would be close to zero,probably no more than a few degrees. How much drop on the rear would somewhat depend on how much power you're going to put down, and how much traction you expect(street tires, slicks...), what you're looking for is near zero at full applied power. This number will obviously be different for different vehicles, a slant six with E78-14s will never wind up the rear like a 600 horse big block with slicks, ya know?
There are many variables here, what's your intended use? Street, drag, both? What springs are you running, Superstock, stock slant six or v8, or HD? How much motor? Stick or auto? How much tire? All things to think about...:coffee2:
There are many variables here, what's your intended use? Street, drag, both? What springs are you running, Superstock, stock slant six or v8, or HD? How much motor? Stick or auto? How much tire? All things to think about...:coffee2:
fishy68
Tyr Fryr's Inc.
That's the way I understand it too. The type of suspension and power applied dictates what the angle diff. should be. Below is a link to a tech article on Moparts that explains things. It has a chart of what the angle should be using different suspensions.
http://www.moparts.org/Tech/Archive/axle/8.html
jet_wrnch
Active Member
Im runnin small block with a little over 500hp with a 4 speed and superstock springs/pinion snubber on radials. Im not going to do to much drag racing with it, but im sure there will be the occasional run
Like the pic in the moparts link near the bottom with an angle finder, Rosseler Trans, do it that way. Put the angle finder on the output shaft, get angle. The angle of the pinion should be opposite that for a "zero" angle. Roll it down form that point to get what you want.
In a 4 speed SS spring car, I'd go about 5-6 down which still may not be enough, but any further and the U joints don't like the workout.
You can set it using operating angles as well.
In a 4 speed SS spring car, I'd go about 5-6 down which still may not be enough, but any further and the U joints don't like the workout.
You can set it using operating angles as well.
jet_wrnch
Active Member
Thanks for the info, now im gonna go home grab an angle finder and give myself a head ache
Supershafts
Well-Known Member
Put the car on stands or on a drive on lift....
1. measure the angle of the driveshaft installed in the car...
2. measure the angle of the pinion or across end yoke
3. set the diff 4.5 degrees opposite the driveshafts angle.
Now when you are under hard load, the rear angle should be 0 or .5 degrees and you won't have additional loss thru angle.
1. measure the angle of the driveshaft installed in the car...
2. measure the angle of the pinion or across end yoke
3. set the diff 4.5 degrees opposite the driveshafts angle.
Now when you are under hard load, the rear angle should be 0 or .5 degrees and you won't have additional loss thru angle.
67Dart273
Well-Known Member
What you neglected, here, is the TRANSMISSION SHAFT angle.
What you ideally want is when the car is under hard accelleration, you want the PINION shaft and the TRANSMISSION shaft PARALLEL
Just like someone else posted:
http://www.moparts.org/Tech/Archive/axle/8.html
Mopar book says 5-7 degrees nose down. That's working angle, not straight measured angle.
Supershafts
Well-Known Member
What you neglected, here, is the TRANSMISSION SHAFT angle.
What you ideally want is when the car is under hard accelleration, you want the PINION shaft and the TRANSMISSION shaft PARALLEL
Just like someone else posted:
http://www.moparts.org/Tech/Archive/axle/8.html
I didn't NEGLECT anything, you chose not to read what i put up and understand what was said...
Building a cruiser never to exceed 3000 rpm follow that factory service manual pinion angle set up...
Building a performance car, follow what i said...
Technically for a performance car, he should align the motor and trans so it is at 0 from end to end, but since most will never get that involved, make the 1 angle right
67Dart273
Well-Known Member
YOU NEGLECTED THE TRANSMISSION SHAFT ANGLE
If you happened to jack the car up so the transmission shaft ANGLE is NOT LEVEL with ground, your instructions will be INCORRECT
(What would you do if this was some wild eye'd "gasser" all jacked up?)
Therefore you NEGLECTED the transmission shaft angle.
This is called "that's how driveshafts work"
The ANGLE is that the two angles of the two u joints MUST CANCEL that is THEY MUST BE THE SAME
The reason for this is that the shaft does NOT turn a "constant speed." The driveshaft actually speeds up and slows down during it's rotation AND THIS IS CAUSED by the angle coming out of the transmission shaft.
The only way to mitigate this CHANGE IN VELOCITY of the driveshaft is to CANCEL it back at the rear axle by having the second angle exactly the same as the first angle.
If you do not know what the first angle is, then you cannot set the second angle.
It's also why, on some 4x4's etc, that a so called "constant velocity" joint is used.
Supershafts
Well-Known Member
A cv head is used to combat 2 opposing angles, or to slow the oscillation (all joints go thru) from to GREAT an ANGLE for the u joint to operate in... (stick to the cars 1st before you get involved with off-road stuff)
Oh boy, ok you tell me how to do this, i'll forget what i do for a moment....
So lets say the trans is at -3 ...
The shaft is at -2 (sloping toward the diff)
what are you setting the pinion angle to..
then i'll show you your mistake and AGAIN answer it in the performance world....
Oh boy, ok you tell me how to do this, i'll forget what i do for a moment....
So lets say the trans is at -3 ...
The shaft is at -2 (sloping toward the diff)
what are you setting the pinion angle to..
then i'll show you your mistake and AGAIN answer it in the performance world....
pettybludart
Well-Known Member
Whats a good angle to set a rear with big slicks and Caltracs?With the Caltracs keeping the rear from moving up or down,whats a good angle to set at?Thanks.
Supershafts
Well-Known Member
If it will limit further movement set it like a ladder bar and use 2.5 - 3 degrees
pettybludart
Well-Known Member
Thanks,always good to get a second opinion.
green1
Well-Known Member
It doesn't have to be level. the rear suspension just has to be loaded(jacked of the floor).
-
