setting pinion angle with jegs non adjustable TA
05-17-2011, 10:49 PM
#1
TECH Apprentice
Thread Starter
iTrader: (16)
Join Date: Dec 2010
Location: Mesquite, Tx
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
setting pinion angle with jegs non adjustable TA I Have heard it needs to be at -2 but i dont know how to get it there its a tunnel mount non adjustable and i have read u set it with the slider one inch out anyone have any pics of how to install it at -2 and how/where to put the angle finder. You have to drill holes with this booger so u got to get it right the first time any help would be awesome guys thanks!
05-18-2011, 06:43 AM
#5
I spent the better part of an hour working on my pinion angle and I learned a few things.
1) The suspension needs to be loaded, so get on a drive-on lift.
2) Have a good angle finder.
3) Follow BMR's instructions on-line.
4) Use some paper and make references.
5) Take all measurements from one side of the car. I used the passanger side. So I would be standing on the passanger side, and looking at the inside of the driverside rim.
6) Take both measurements and know that you have to picture the Driveshaft and Rear end diff as 2 seperate lines.
7) IF you can, use 2 angle finders at the same time. Makes it easier to figure out reference.
8) Rear end is Negative if it slopes down towards the front of the car and Positive if ramps up towards the front of the car. D/S is Positive if ramps up towards the back of the car and Negative if it slopes down to the rear of the car.
(Rear End Angle) + (Drive Shaft Angle) = Pinion Angle
Example: Do not take too litteral.
(-1) rear end angle + (-1) driveshaft angle = (-2) degrees. Yes!
(-5) rear end angle + (-2) driveshaft angle = (-7) degrees. No!
(0) rear end angle + (2) driveshaft angle = (+2) degrees. No!
(-3) rear end angle + (5) driveshaft angle = (+2) degrees. NO!
(3) rear end angle + (-5) driveshaft angle = (-2) degrees. YES!
** I had one guage (used to have 2 darn!) so once I picked my side I would start taking measurements. On a seperate sheet of paper I then drew a circle and put the Negative and Positive reference on there to help me remind me when the rear end tilted down then I was going negative and when the DS was going up, I was going Positive.
If the top of the circle is "Zero" then on the rear end, if the diff tilted down any # to the left of the needle was negative, and anything to the right was a positive number. Then on the D/S anything on the right became negative and anything on the left was positive.
So long story made short, we were making a mistake in reading the numbers on the guage as the same for both measurements. Since we are trying to find out the pinion angle we need to understand that the U-joint between the DS and Yoke is the focal point that the results will become mirror opposites.
So for you. I would get an Adj. TQ arm and resell yours.
1) The suspension needs to be loaded, so get on a drive-on lift.
2) Have a good angle finder.
3) Follow BMR's instructions on-line.
4) Use some paper and make references.
5) Take all measurements from one side of the car. I used the passanger side. So I would be standing on the passanger side, and looking at the inside of the driverside rim.
6) Take both measurements and know that you have to picture the Driveshaft and Rear end diff as 2 seperate lines.
7) IF you can, use 2 angle finders at the same time. Makes it easier to figure out reference.
8) Rear end is Negative if it slopes down towards the front of the car and Positive if ramps up towards the front of the car. D/S is Positive if ramps up towards the back of the car and Negative if it slopes down to the rear of the car.
(Rear End Angle) + (Drive Shaft Angle) = Pinion Angle
Example: Do not take too litteral.
(-1) rear end angle + (-1) driveshaft angle = (-2) degrees. Yes!
(-5) rear end angle + (-2) driveshaft angle = (-7) degrees. No!
(0) rear end angle + (2) driveshaft angle = (+2) degrees. No!
(-3) rear end angle + (5) driveshaft angle = (+2) degrees. NO!
(3) rear end angle + (-5) driveshaft angle = (-2) degrees. YES!
** I had one guage (used to have 2 darn!) so once I picked my side I would start taking measurements. On a seperate sheet of paper I then drew a circle and put the Negative and Positive reference on there to help me remind me when the rear end tilted down then I was going negative and when the DS was going up, I was going Positive.
If the top of the circle is "Zero" then on the rear end, if the diff tilted down any # to the left of the needle was negative, and anything to the right was a positive number. Then on the D/S anything on the right became negative and anything on the left was positive.
So long story made short, we were making a mistake in reading the numbers on the guage as the same for both measurements. Since we are trying to find out the pinion angle we need to understand that the U-joint between the DS and Yoke is the focal point that the results will become mirror opposites.
So for you. I would get an Adj. TQ arm and resell yours.
Last edited by BlackScreaminMachine; 05-18-2011 at 07:09 AM.
05-18-2011, 07:52 AM
#6
If you have good suspension parts in the car... I would highly suggest you put it at 0 and start there. Adding pinion angle with a suspension like these cars have is not going to do what it did with a leaf spring car that had an axle that wrapped in a circle when you launched it..... only thing you are really doing is adding a mechanical bind to the driveline, and making the car have to work harder to turn the driveshaft.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
05-18-2011, 08:12 AM
#7
TECH Fanatic
iTrader: (9)
Join Date: Mar 2004
Location: Pasadena Texas
Posts: 1,318
Likes: 0
Received 0 Likes
on
0 Posts
If you have good suspension parts in the car... I would highly suggest you put it at 0 and start there. Adding pinion angle with a suspension like these cars have is not going to do what it did with a leaf spring car that had an axle that wrapped in a circle when you launched it..... only thing you are really doing is adding a mechanical bind to the driveline, and making the car have to work harder to turn the driveshaft.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
Trending Topics
05-18-2011, 08:17 AM
#8
^ agreed, Ultimately you have to tune your car to suit your needs and combination. The info I provide is my exp. in doing this and sometimes the confusion that follows. The one thing no one ever talks about is the reference points for the readings and if you can, or if you do this a lot is to have 2 guages and if you can swing it, have them be electronic for ease of use.
In the BMR video you see then using 2 and it makes a world of difference.
In the BMR video you see then using 2 and it makes a world of difference.
05-18-2011, 11:40 AM
#10
^ agreed, Ultimately you have to tune your car to suit your needs and combination. The info I provide is my exp. in doing this and sometimes the confusion that follows. The one thing no one ever talks about is the reference points for the readings and if you can, or if you do this a lot is to have 2 guages and if you can swing it, have them be electronic for ease of use.
In the BMR video you see then using 2 and it makes a world of difference.
In the BMR video you see then using 2 and it makes a world of difference.
Hello Can of worms, let me open you up.
05-18-2011, 01:36 PM
#11
TECH Fanatic
iTrader: (9)
Join Date: Mar 2004
Location: Pasadena Texas
Posts: 1,318
Likes: 0
Received 0 Likes
on
0 Posts
Last edited by 1lejohn; 05-18-2011 at 01:45 PM.
05-18-2011, 02:20 PM
#12
LOL. I laugh every time I read this stuff.. people worry about "pinion angle" so much they're stuck in 1960........
Level ground, make sure the rear is parallel with the ground. That's all you have to do... rake of the chassis has the engine/tranny line sitting level if you have the rake set right, done deal.
But, carry on with the conversation. I do get a good laugh out of how over-complicated everyone makes this... not to mention, with our cars, if you have good rod ended suspension in it... it doesn't matter, there IS no deflection!
05-18-2011, 04:48 PM
#13
TECH Fanatic
iTrader: (9)
Join Date: Mar 2004
Location: Pasadena Texas
Posts: 1,318
Likes: 0
Received 0 Likes
on
0 Posts
I hear you. I've spent about 6 mos doing research and adjusting the arm back and forth. Hell I started at neut (zero) all done with ride height and just bolting up the T arm. I learned the hard way. I also agree if the engine and trans are in the stock locations then the chassis will be close to neutral. Gm designed it that way.
05-18-2011, 06:06 PM
#14
What I can say is that everyone will a specific level of comfort. Its not overly complicated but people get confused when companies really don't explain the concept behind it. All they explain is what you want. But not the "why". Level ground is all that is needed and the last thing people need is miscalculation and have - 7 degrees.
The lenght of the TQ arm or how/where it attatches to the car will have more of an impact then pinion angle. IMO.
The lenght of the TQ arm or how/where it attatches to the car will have more of an impact then pinion angle. IMO.
05-18-2011, 06:18 PM
#15
Tq arm length doesn't have anything to do with it either. the length, is just one way of people changing the instant center point. You could have a tq arm that's 14 inches long, or one that's 72 inches long. Where the center line of the tq arm and where the center line of the lower control arms intersect on the other hand, have ALOT to do with it. Move that centerlone up, down, forward or backwards, and you can go from doing nothing but spinning to flipping the car over. Any arm can do the same thing as another if you can adjust it to cross the lines at the right point. Madman's arm, has the adjustment built into it to be able to do this, and with the right front attachment design (slider, not a hinge) to make it work properly.
Regardless, of pinion angle.
Regardless, of pinion angle.
05-18-2011, 06:29 PM
#16
On The Tree
If you have good suspension parts in the car... I would highly suggest you put it at 0 and start there. Adding pinion angle with a suspension like these cars have is not going to do what it did with a leaf spring car that had an axle that wrapped in a circle when you launched it..... only thing you are really doing is adding a mechanical bind to the driveline, and making the car have to work harder to turn the driveshaft.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
I ran my car a -.5 degree, becuase that's what it had to be at so as the suspension conpressed it never went positive. At ride height, it was -.5, and as far down as the car ever compressed at the track (I pulled the back of the car down until the tires were hit, which they never did at the track) the angle was @ 0.
Worked for me, car went on the bumper with that setting.... certainly wasn't hurting anything in the traction department.
05-18-2011, 08:32 PM
#17
Tq arm length doesn't have anything to do with it either. the length, is just one way of people changing the instant center point. You could have a tq arm that's 14 inches long, or one that's 72 inches long. Where the center line of the tq arm and where the center line of the lower control arms intersect on the other hand, have ALOT to do with it. Move that centerlone up, down, forward or backwards, and you can go from doing nothing but spinning to flipping the car over. Any arm can do the same thing as another if you can adjust it to cross the lines at the right point. Madman's arm, has the adjustment built into it to be able to do this, and with the right front attachment design (slider, not a hinge) to make it work properly.
Regardless, of pinion angle.
Regardless, of pinion angle.
Mine was way out of whack and bring it @ -2 or -1.5 made a big diff in vibration dept. That is what I can say.
05-18-2011, 08:37 PM
#18
The vibration could also be a sign of something else as well. If the yoke is loose in the tranny, u joint isn't as tight as it once was, etc, all will show up more depending on the amount they are worked.
You could have adjusted the pinion angle so that it's not riding in the same spot in the total motion range of the ujoint, causing the vibration to decrease and could still have the pinion angle wrong.
Get the car on level ground, with you in it. Put the angle finder on the rear end and see what it is compared to the ground. If it's off by more then 1/2 a degree, something is wrong, wether it's the rake of the chassis of the car, or the actual pinion angle.
You could have adjusted the pinion angle so that it's not riding in the same spot in the total motion range of the ujoint, causing the vibration to decrease and could still have the pinion angle wrong.
Get the car on level ground, with you in it. Put the angle finder on the rear end and see what it is compared to the ground. If it's off by more then 1/2 a degree, something is wrong, wether it's the rake of the chassis of the car, or the actual pinion angle.
