Vibration
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From: Botswana
Originally posted by whitebolt01
I did read them, and from what I read the pinion angle should be 5.7 degrees. So when I measure it and find out what it is I will post my results.
Thanks,
Simon
I did read them, and from what I read the pinion angle should be 5.7 degrees. So when I measure it and find out what it is I will post my results.
Thanks,
Simon
Here is a link that was in the same thread on the proper way to measure the angle. I am posting it just in case you missed it. http://www.buickperformance.com/Pinion.htm
If your going to drag race it...you may want a slight negative angle. Mine is about -2 degrees so that when I launch and the pinion moves up, it is in line with the drive shaft, rather than above it...which could create a busted shaft.
Last edited by 03LightninRocks; Aug 15, 2004 at 01:33 PM.
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From: Botswana
Let me make sure you understand. I am no authority on suspension set up. I friend and I checked mine about 2 years ago. Mine was set up at -2 degrees and it doesn't vibrate at any speed. My pinion also doesn't try to bind from launching, by lifting up into a positive angle.
I have read that every vehicle can respond differently to pinion angle. I can tell you for sure that having a positive pinion angle(pinion pointing up) or even a zero angle that can turn positive on a hard launch, can bust off the drive shaft.
I copied this info from a link to help you to measure it and have a starting point.
The Watson Guide to Happy Pinion Angles
Here is Craig Watson's guide to checking the relative angle between the centerline of the pinion gear in the rearend and the centerline of the driveshaft. This is known as pinion angle.
Pinion angle is important due to the forces at work in the rearend and rear suspension of a rearwheel drive vehicle. As power is applied to the rearend via the driveshaft, the pinion gear tries to climb the ring gear. This causes the rearend housing (along with the pinion gear) to rotate about the axles' centerline. The optimum relationship between the pinion gear and driveshaft is when they are perfectly aligned. In order to achieve this under power, you much have some angle built into the setup when the vehicle is at rest and not under any power.
The typical leaf spring rear suspension will need 5-7 degrees of negative angle. A ladder bar or 4-link setup is much more rigid and therefore usually only needs 1-3 degrees. You never want the the rearend setup with positive pinion angle. This is when the yoke of the rearend is tilted upward more than the driveshaft. This can lead to binding of the u-joints and will hurt traction (the real reason we enthusiasts are concerned about this).
To check the pinion angle, the vehicle needs to be sitting with its weight on the tires, as it would be normally. For the best accuracy, place weight in the driver's seat to simulate the driver. An angle finder can be bought from places such as Sears for about $10.
Begin by measuring the angle of the driveshaft and writing it down. Then remove the driveshaft from the yoke (no need to totally remove it and spin tranny fluid everywhere) and place the angle finder on the end of the yoke. The angle from vertical will be equal to the angle of the centerline of the pinion gear to the horizontal. If the driveshaft was angled upward (it would be rare to find one that isn't) and the rearend is nose down (not always the case, so be sure you know which way its positioned), just add together the two angles you measured. For instance, if the driveshaft is 2 degrees up from level and the pinion gear is 3 degrees nose down, then you have 5 degrees of pinion angle. If the rearend is nose up and its angle is less than the angle of the driveshaft, subtract the rearend angle from the driveshaft angle. If the angle of the rearend is steeper than that of the driveshaft, subtract the angle of the driveshaft from that of the rearend to see how much positive pinion angle you have. For example, if you have a rearend angle of 5 degrees from vertical nose up and the driveshaft is angled up at 3 degrees, you have 2 degrees of positive pinion angle. If this was a leaf spring car, you'd need to change the angle by 7 degrees to get 5 degrees of negative pinion angle.
If the rearend is so close to level that you can't tell if its nose up or nose down, put the angle finder on the yoke and then see which direction you have to rotate the finder to make it read zero (or 90 depending on how the angle finder is made). When viewed from the passenger side, if you have to rotate it counterclockwise, the rearend is nose down.
Now that you know the pinion angle, you may have to change it. On a leaf spring car, this is done with wedges between the rearend and the springs. Speed shops and sometimes alignment shops keep these around. If you can't find them locally, Summit and Jegs carry them. If you have a factory 4-link car, you'll need some adjustable control arms or revised control arm mounts. Aftermarket ladder bar and 4-link cars are adjusted via the Heim joints. For a graphic description of all this, click here.
If you have any questions, additions or corrections, please e-mail me at craig@2quicknovas.com
I have read that every vehicle can respond differently to pinion angle. I can tell you for sure that having a positive pinion angle(pinion pointing up) or even a zero angle that can turn positive on a hard launch, can bust off the drive shaft.
I copied this info from a link to help you to measure it and have a starting point.
The Watson Guide to Happy Pinion Angles
Here is Craig Watson's guide to checking the relative angle between the centerline of the pinion gear in the rearend and the centerline of the driveshaft. This is known as pinion angle.
Pinion angle is important due to the forces at work in the rearend and rear suspension of a rearwheel drive vehicle. As power is applied to the rearend via the driveshaft, the pinion gear tries to climb the ring gear. This causes the rearend housing (along with the pinion gear) to rotate about the axles' centerline. The optimum relationship between the pinion gear and driveshaft is when they are perfectly aligned. In order to achieve this under power, you much have some angle built into the setup when the vehicle is at rest and not under any power.
The typical leaf spring rear suspension will need 5-7 degrees of negative angle. A ladder bar or 4-link setup is much more rigid and therefore usually only needs 1-3 degrees. You never want the the rearend setup with positive pinion angle. This is when the yoke of the rearend is tilted upward more than the driveshaft. This can lead to binding of the u-joints and will hurt traction (the real reason we enthusiasts are concerned about this).
To check the pinion angle, the vehicle needs to be sitting with its weight on the tires, as it would be normally. For the best accuracy, place weight in the driver's seat to simulate the driver. An angle finder can be bought from places such as Sears for about $10.
Begin by measuring the angle of the driveshaft and writing it down. Then remove the driveshaft from the yoke (no need to totally remove it and spin tranny fluid everywhere) and place the angle finder on the end of the yoke. The angle from vertical will be equal to the angle of the centerline of the pinion gear to the horizontal. If the driveshaft was angled upward (it would be rare to find one that isn't) and the rearend is nose down (not always the case, so be sure you know which way its positioned), just add together the two angles you measured. For instance, if the driveshaft is 2 degrees up from level and the pinion gear is 3 degrees nose down, then you have 5 degrees of pinion angle. If the rearend is nose up and its angle is less than the angle of the driveshaft, subtract the rearend angle from the driveshaft angle. If the angle of the rearend is steeper than that of the driveshaft, subtract the angle of the driveshaft from that of the rearend to see how much positive pinion angle you have. For example, if you have a rearend angle of 5 degrees from vertical nose up and the driveshaft is angled up at 3 degrees, you have 2 degrees of positive pinion angle. If this was a leaf spring car, you'd need to change the angle by 7 degrees to get 5 degrees of negative pinion angle.
If the rearend is so close to level that you can't tell if its nose up or nose down, put the angle finder on the yoke and then see which direction you have to rotate the finder to make it read zero (or 90 depending on how the angle finder is made). When viewed from the passenger side, if you have to rotate it counterclockwise, the rearend is nose down.
Now that you know the pinion angle, you may have to change it. On a leaf spring car, this is done with wedges between the rearend and the springs. Speed shops and sometimes alignment shops keep these around. If you can't find them locally, Summit and Jegs carry them. If you have a factory 4-link car, you'll need some adjustable control arms or revised control arm mounts. Aftermarket ladder bar and 4-link cars are adjusted via the Heim joints. For a graphic description of all this, click here.
If you have any questions, additions or corrections, please e-mail me at craig@2quicknovas.com
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From: Botswana
whitebolt01......................Thanks to your post, I have been reading alot of the pinion threads the past few hours...LOL. I have the 03 and was getting curious about why some had to pull the shims out and others had to turn them around. Mine worked without any problems.
I noticed you asked about the 04 angles, so I am assuming you have an 04.
After reading all these posts, If I had the vibration you describe, I would probably remove the shims and see what develops. Several posted that they had success with this. I also would do like a few recommended and get it realigned afterwards if this solves your vibration.....
Just thinking out loud
Rocks
I noticed you asked about the 04 angles, so I am assuming you have an 04.
After reading all these posts, If I had the vibration you describe, I would probably remove the shims and see what develops. Several posted that they had success with this. I also would do like a few recommended and get it realigned afterwards if this solves your vibration.....
Just thinking out loud
Rocks
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From: The Woodlands, Texas
03LightningRocks,
Thanks for all your input. I just drove the truck today and there was no vibration at 60-70, I only had the vibration on the freeway on my way to Auburn, Alabama. I am goin to have my alignment done tomorrow to see if it has anything to do with it. If the vibartion comes back I will remove the shims.
Thanks,
Simon
Thanks for all your input. I just drove the truck today and there was no vibration at 60-70, I only had the vibration on the freeway on my way to Auburn, Alabama. I am goin to have my alignment done tomorrow to see if it has anything to do with it. If the vibartion comes back I will remove the shims.
Thanks,
Simon
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Joined: Nov 2002
Posts: 1,833
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From: Botswana
Originally posted by whitebolt01
03LightningRocks,
Thanks for all your input. I just drove the truck today and there was no vibration at 60-70, I only had the vibration on the freeway on my way to Auburn, Alabama. I am goin to have my alignment done tomorrow to see if it has anything to do with it. If the vibartion comes back I will remove the shims.
Thanks,
Simon
03LightningRocks,
Thanks for all your input. I just drove the truck today and there was no vibration at 60-70, I only had the vibration on the freeway on my way to Auburn, Alabama. I am goin to have my alignment done tomorrow to see if it has anything to do with it. If the vibartion comes back I will remove the shims.
Thanks,
Simon
One more suggestion.........be sure and check out the FFWn Dallas this year. I know the HALO group is going to be there....you should come out too.
Rocks
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From: The Woodlands, Texas
I would if I was still in town, went back to Auburn University this weekend and that is when I noticed the vibration. The vibration has gone away but now on the 2-3 shift I have this sort of metal on metal sound like the driveshaft rubbing. Have no idea, any ideas on what it is?
Thanks,
Simon
Thanks,
Simon
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From: The Woodlands, Texas
Well I went to a truck shop that knows what they are doin and said that the pinion angle looks fine. He also said maybe the tires need to be alinged and balanced. Could that be the cause? All the vibrations i have heard of with shackles are low speed and mine is from 60-70.
What are some other problems it could be?
Thanks,
Simon
What are some other problems it could be?
Thanks,
Simon
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Joined: Apr 2003
Posts: 294
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From: AZ
READ THIS AND TRY IT
I pulled my hair out pissing away time looking at pinion angles and all other possible problems. It was too simple. You can check out all the play by play here:
http://www.nloc.net/forum/showthread...threadid=73879
http://www.nloc.net/forum/showthread...threadid=73879
Last edited by hyvltge; Aug 17, 2004 at 05:31 PM.
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From: The Woodlands, Texas
hyvltge
What was the fix, sorry couldnt find it?
Coudl you email me at cobra_93_svt@yahoo.com, with the solution?
Thanks,
Simon
What was the fix, sorry couldnt find it?
Coudl you email me at cobra_93_svt@yahoo.com, with the solution?
Thanks,
Simon
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From: The Woodlands, Texas
I finally got around ro measuring it with the gauge Ryan Allen suggested. Thanks for the help with that Ryan. The angle between the tranny and ds is 0 degrees. and the angle between the ds and rearend was about 5.5 degrees. Does this sound right? I couldnt really see the gauge that well, the trac bars hindered me from getting under there so these are the angles plus or minus .1 of a degree. Also, the vibration came back so I think the pinion angle is off. Please let me know if these angles seem right.
Thanks,
Simon
Thanks,
Simon
Thread Starter
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Senior Member
Joined: Jun 2003
Posts: 362
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From: The Woodlands, Texas
I finally got around ro measuring it with the gauge Ryan Allen suggested. Thanks for the help with that Ryan. The angle between the tranny and ds is 0 degrees. and the angle between the ds and rearend was about 5.5 degrees. Does this sound right? I couldnt really see the gauge that well, the trac bars hindered me from getting under there so these are the angles plus or minus .1 of a degree. Also, the vibration came back so I think the pinion angle is off. Please let me know if these angles seem right.
Thanks,
Simon
Thanks,
Simon
