How to read an Angle Finder correctly?
12-05-2007, 07:59 PM
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How to read an Angle Finder correctly? OK im having trouble reading the angle finder upside down, plus my car is very low so it's hard enough as it is. It is a hanging needle version.
From the driver's side what side of 0 is negative? Pics would be very helpful. The yoke looks like it is pointing down i'm just not 100% positive i have it right.
From the driver's side what side of 0 is negative? Pics would be very helpful. The yoke looks like it is pointing down i'm just not 100% positive i have it right.
12-06-2007, 01:16 AM
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First, jack up the back end a bit by the differential to make sure you can get to the pinion yoke to measure an angle. Before you do that, measure the angle on the front face of your crank pulley. Whatever that reads, make the face of your pinion yoke the same. That puts you at zero. Then adjust your pinion angle accordingly to whatever you want--usually down a half to two degrees. Tighten things up and you're done.
12-07-2007, 04:26 PM
#3
disclaimer: I copied this from someone back in 2003 , don't recall who so it's not my words. But it is what I used to set pinion angle.
---------------------------------------------------------------------------------
Don't bother using the shitty, incorrect instructions that come from Spohn on how to set your Pinion Angle.
They tell you to measure the angle of your DS and then measure the angle of rear. Measuring the angle of the DS doesn't tell you jack **** that you need to know to properly set the angle.
The DS could be at any angle depending on the load on the wheels and thru the full range of the suspension travel. Take for example a truck that has a lift kit installed - do you really think the DS angle is anywhere near being the same as a truck without a lift? Measuring the actual DS angle does not tell you anything about the angle of the engine/tranny as it can swivel on the tranny yoke U-joint independant of the tranny angle.
Here is the CORRECT way to set PA as I recently found out straight from a GM engineer after trying the 20 some different ways that are described:
1) Have car on alignment rack that supports car by tires or raise car in such a manner as to put load on all (4) tires as if car was on ground.
2) Remove DS (making sure to make a reference mark on pinion yoke and corresponding mark on DS rear yoke to allow for same position when you bolt back up)
3) Using an angle finder, first measure the angle of the engine/tranny combo by placing gage on output shaft tailshaft housing face. Record this angle and note whether it is pointing down to ground or up (most likely will be pointing down).
4) Using an angle finder, then measure the angle of the rear by placing gage on face of pinion yoke where U-joint straps interface. Record this angle and again note whether it is pointing up or down.
U-joints are designed to work best in conjunction with one another when the angle imparted to them on each end of the DS is the same, yet in opposite direction. Think of an imaginary centerline thru your crankshaft/tranny output shaft and another thru your rear pinion shaft. If you were to draw these (2) lines they would need to be PARALLEL to each other (not in-line but parallel) to allow the best operating conditions for the u-joints and the least vibration.
So it follows:
5) If your tranny measurement is 2 degrees pointing DOWN - then your rear angle should be 2 degrees pointing UP. This would yield a zero degree pinion angle and is where your car is set up from the factory. For strip cars with high HP/TQ and good tires, you can impart a -1 to -2 degree angle relationship between the rear and tranny angles. This is due to the fact that the rear rotates thru an arc upwards under high loads - so if you give it a negative angle to begin with, when it finally is done rotating upwards - the angle will come back to zero.
So if you wanted to do this, and the tranny angle is 2 degrees DOWN - then you would want to set the rear angle to 1 degree UP for -1 and zero for -2.
6) Re-install DS aligning the positioning marks on rear yoke that you made in step 2. Torque U-joint strap bolts to 14-19lb ft and use loctite on the bolts.
---------------------------------------------------------------------------------
Don't bother using the shitty, incorrect instructions that come from Spohn on how to set your Pinion Angle.
They tell you to measure the angle of your DS and then measure the angle of rear. Measuring the angle of the DS doesn't tell you jack **** that you need to know to properly set the angle.
The DS could be at any angle depending on the load on the wheels and thru the full range of the suspension travel. Take for example a truck that has a lift kit installed - do you really think the DS angle is anywhere near being the same as a truck without a lift? Measuring the actual DS angle does not tell you anything about the angle of the engine/tranny as it can swivel on the tranny yoke U-joint independant of the tranny angle.
Here is the CORRECT way to set PA as I recently found out straight from a GM engineer after trying the 20 some different ways that are described:
1) Have car on alignment rack that supports car by tires or raise car in such a manner as to put load on all (4) tires as if car was on ground.
2) Remove DS (making sure to make a reference mark on pinion yoke and corresponding mark on DS rear yoke to allow for same position when you bolt back up)
3) Using an angle finder, first measure the angle of the engine/tranny combo by placing gage on output shaft tailshaft housing face. Record this angle and note whether it is pointing down to ground or up (most likely will be pointing down).
4) Using an angle finder, then measure the angle of the rear by placing gage on face of pinion yoke where U-joint straps interface. Record this angle and again note whether it is pointing up or down.
U-joints are designed to work best in conjunction with one another when the angle imparted to them on each end of the DS is the same, yet in opposite direction. Think of an imaginary centerline thru your crankshaft/tranny output shaft and another thru your rear pinion shaft. If you were to draw these (2) lines they would need to be PARALLEL to each other (not in-line but parallel) to allow the best operating conditions for the u-joints and the least vibration.
So it follows:
5) If your tranny measurement is 2 degrees pointing DOWN - then your rear angle should be 2 degrees pointing UP. This would yield a zero degree pinion angle and is where your car is set up from the factory. For strip cars with high HP/TQ and good tires, you can impart a -1 to -2 degree angle relationship between the rear and tranny angles. This is due to the fact that the rear rotates thru an arc upwards under high loads - so if you give it a negative angle to begin with, when it finally is done rotating upwards - the angle will come back to zero.
So if you wanted to do this, and the tranny angle is 2 degrees DOWN - then you would want to set the rear angle to 1 degree UP for -1 and zero for -2.
6) Re-install DS aligning the positioning marks on rear yoke that you made in step 2. Torque U-joint strap bolts to 14-19lb ft and use loctite on the bolts.
Last edited by Viper; 12-20-2007 at 03:59 PM.
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12-07-2007, 08:43 PM
#9
spohn told me to measure from the drivers side. bottom of the driveshaft and bottom plate of the torque arm. DS angle is +, and torque arm plate angle is -. This is just what I was told.
12-09-2007, 03:46 PM
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Thanks i got it. Trial and error. Driving a car with positive 2 degree angle is NO fun. hahaha. Oh well live and learn.
And yes it is left neg. / right pos.
And yes it is left neg. / right pos.
12-19-2007, 01:55 AM
#15
Don't bother using the shitty, incorrect instructions that come from Spohn on how to set your Pinion Angle.
They tell you to measure the angle of your DS and then measure the angle of rear. Measuring the angle of the DS doesn't tell you jack **** that you need to know to properly set the angle.
The DS could be at any angle depending on the load on the wheels and thru the full range of the suspension travel. Take for example a truck that has a lift kit installed - do you really think the DS angle is anywhere near being the same as a truck without a lift? Measuring the actual DS angle does not tell you anything about the angle of the engine/tranny as it can swivel on the tranny yoke U-joint independant of the tranny angle.
Here is the CORRECT way to set PA as I recently found out straight from a GM engineer after trying the 20 some different ways that are described:
1) Have car on alignment rack that supports car by tires or raise car in such a manner as to put load on all (4) tires as if car was on ground.
2) Remove DS (making sure to make a reference mark on pinion yoke and corresponding mark on DS rear yoke to allow for same position when you bolt back up)
3) Using an angle finder, first measure the angle of the engine/tranny combo by placing gage on output shaft tailshaft housing face. Record this angle and note whether it is pointing down to ground or up (most likely will be pointing down).
4) Using an angle finder, then measure the angle of the rear by placing gage on face of pinion yoke where U-joint straps interface. Record this angle and again note whether it is pointing up or down.
U-joints are designed to work best in conjunction with one another when the angle imparted to them on each end of the DS is the same, yet in opposite direction. Think of an imaginary centerline thru your crankshaft/tranny output shaft and another thru your rear pinion shaft. If you were to draw these (2) lines they would need to be PARALLEL to each other (not in-line but parallel) to allow the best operating conditions for the u-joints and the least vibration.
So it follows:
5) If your tranny measurement is 2 degrees pointing DOWN - then your rear angle should be 2 degrees pointing UP. This would yield a zero degree pinion angle and is where your car is set up from the factory. For strip cars with high HP/TQ and good tires, you can impart a -1 to -2 degree angle relationship between the rear and tranny angles. This is due to the fact that the rear rotates thru an arc upwards under high loads - so if you give it a negative angle to begin with, when it finally is done rotating upwards - the angle will come back to zero.
So if you wanted to do this, and the tranny angle is 2 degrees DOWN - then you would want to set the rear angle to 1 degree UP for -1 and zero for -2.
6) Re-install DS aligning the positioning marks on rear yoke that you made in step 2. Torque U-joint strap bolts to 14-19lb ft and use loctite on the bolts.
They tell you to measure the angle of your DS and then measure the angle of rear. Measuring the angle of the DS doesn't tell you jack **** that you need to know to properly set the angle.
The DS could be at any angle depending on the load on the wheels and thru the full range of the suspension travel. Take for example a truck that has a lift kit installed - do you really think the DS angle is anywhere near being the same as a truck without a lift? Measuring the actual DS angle does not tell you anything about the angle of the engine/tranny as it can swivel on the tranny yoke U-joint independant of the tranny angle.
Here is the CORRECT way to set PA as I recently found out straight from a GM engineer after trying the 20 some different ways that are described:
1) Have car on alignment rack that supports car by tires or raise car in such a manner as to put load on all (4) tires as if car was on ground.
2) Remove DS (making sure to make a reference mark on pinion yoke and corresponding mark on DS rear yoke to allow for same position when you bolt back up)
3) Using an angle finder, first measure the angle of the engine/tranny combo by placing gage on output shaft tailshaft housing face. Record this angle and note whether it is pointing down to ground or up (most likely will be pointing down).
4) Using an angle finder, then measure the angle of the rear by placing gage on face of pinion yoke where U-joint straps interface. Record this angle and again note whether it is pointing up or down.
U-joints are designed to work best in conjunction with one another when the angle imparted to them on each end of the DS is the same, yet in opposite direction. Think of an imaginary centerline thru your crankshaft/tranny output shaft and another thru your rear pinion shaft. If you were to draw these (2) lines they would need to be PARALLEL to each other (not in-line but parallel) to allow the best operating conditions for the u-joints and the least vibration.
So it follows:
5) If your tranny measurement is 2 degrees pointing DOWN - then your rear angle should be 2 degrees pointing UP. This would yield a zero degree pinion angle and is where your car is set up from the factory. For strip cars with high HP/TQ and good tires, you can impart a -1 to -2 degree angle relationship between the rear and tranny angles. This is due to the fact that the rear rotates thru an arc upwards under high loads - so if you give it a negative angle to begin with, when it finally is done rotating upwards - the angle will come back to zero.
So if you wanted to do this, and the tranny angle is 2 degrees DOWN - then you would want to set the rear angle to 1 degree UP for -1 and zero for -2.
6) Re-install DS aligning the positioning marks on rear yoke that you made in step 2. Torque U-joint strap bolts to 14-19lb ft and use loctite on the bolts.
Picture a 4wd truck the drive shaft points down towards the rearend... if you set you pinion angle like you said your **** would break. Pinon angle is the relation between the driveshaft angle and pinion angle.
Eg. if D/S is down 10dg then your rear should be up 8 dg.
Visually your rear should be very close to your D/S angle.
Doug
