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I posted before about driveshaft vibrations and some suggestions were driveshaft balance and to check the pinion angle. I got the driveshaft balanced and it took away most of the vibrations but it still peaks at 50-60mph. What is the correct pinion angle? Doesn't the angle change under load? Its a 70 camaro th350 if that has any affect on the angle. Im assuming pinion and is angle of shaft to rear. Thanks for any help.
 

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I'm setting mine to 4 degrees down from level when the driveline is not under a load (not moving) i'm setting to 4 degrees becuase some of the other forum members recommended it.
It DOES change with a load, thats why you set it to say 4 degrees, becuase you want it to be 0 degrees under a load. The axles put a "twist" or "torque" on the rear when your moving and the pinion will rise a few degrees, the more it twists the more the pinion will rise.
 

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To be exactly precise, the angle of the pinion should be relative to the angle of the output shaft of the transmission. A few degrees down will help to compensate for axle wrap up under load so that the pinion angle is equal to, or parallel to, the output shaft when it is under a load. As a general rule, the pinion angle shouldn't be set relative to the ground, or exact level, but to the output shaft of the transmission.
 

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<BLOCKQUOTE>quote:</font><HR>Originally posted by CamaroNOTcamero:
I'm setting mine to 4 degrees down from level when the driveline is not under a load (not moving) i'm setting to 4 degrees becuase some of the other forum members recommended it.
<HR></BLOCKQUOTE>

Just to be clear CNC, when you say "not under load" you mean torque load don't you. You definately do want the vehicle weight load on the rear axle when making this adjustment. I think that is what you meant, but wanted to be sure.
 

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hey guys, now i am installing a ford 9 in my 68 camaro, what is the best way to weld the perches on at the right angle??? i want to make it right and how do i do that?? do i set perches on leaf springs, the set rearend on perches in car,center axle,then measure pinion angle and then tack weld perches, then take out and weld solid>??? also how can i make it like the vehucle weight is on it when the perches are not welded and i have to rotate the axle to get correct angle??? please give me a explanation, i would greatly appreciate it, thanks Jake
 

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Yeah, torque load, not weight from the car.
I set it up using a GM diagram, so i'm willing to bet that i'm safe since thats the way the general did it.
 

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Hey Guys,

Help me with this one!! The diagram shown above from Inland Empire Driveline looks to me like the pinion angle is set 3 or 4 degrees ABOVE level. I keep reading about people setting them BELOW level. Am I missing something here or just looking at this upside down??

Doug




[This message has been edited by GDV350SS (edited 08-14-2002).]
 

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Discussion Starter #9
I agree the diagram is above level, is that what it is suppose to be? Right now mine is below level by probably a little more than four degrees, could that cause the vibration I described?
 

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The GM diagram i got showed it down, not up like inline empire.
I dont understand why they would want it 3 degrees up, when under full throttlw it would have the potential to move to 7 degrees or more up, and i think that would cuase vibrations.
Steve jack, any reason why that diagram is like that?
 

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It would depend on which direction you transmission is pointing. If it is pointing down like in the photo above, then your pinion should point up like in the photo, so that they are parallel. If your tranny points up, then your pinion should point down so that they will be parallel.

I think the tranny pointing up is more common, but sometimes it points down, like when you have a Tremec and can't push the rear of the tranny up anymore because it hits the trans tunnel.

The important thing is that the two center lines are parallel, and that the angle of them to the driveshaft isn't too large, 3 degress max according to the photo above.

Ray www.geocities.com/hrayhouston
 

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It is my understanding (I read it on this sight and believe it was from someone knowledgeable but can’t remember who) that the standard configuration for a 1st gen Camaro using standard motor and transmission mounts puts the transmission at approximately 4 degrees down. If this is indeed correct, than the pinion needs to be up 4 degrees to be parallel. Any thoughts or more knowledge about this would be appreciated.

The more I learn the less I know!

Doug
 

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It is my understanding (I read it on this sight and believe it was from someone knowledgeable but can’t remember who) that the standard configuration for a 1st gen Camaro using standard motor and transmission mounts puts the transmission at approximately 4 degrees down. If this is indeed correct, than the pinion needs to be up 4 degrees to be parallel. Any thoughts or more knowledge about this would be appreciated.

steve70: I hope that we get to figure this out because I beleive it may be the cause of your vibration as well as mine.

The more I learn the less I know!

Doug



[This message has been edited by GDV350SS (edited 08-15-2002).]
 

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Guys. A couple of points here.

First, Steve70, if your angle does not look like the diagram.....Yes indeed the vibration is coming from mismatched angles. The center line of the crankshaft and transmission output shaft must be parallel to the center line of the pinion shaft as shown in the figure above. There are NO exceptions to this configuration unless you are a serious drag racer.

Camaronotcamaro....wrap up doesn't always happen if corrected for. And, you set the driveline for the most common mode of operation...cruising which the pinion is basically in a static mode. After initial wrap up deflection, the angle starts to decrease proportionately. If you are using the car just for drags then angles should be studied further for optimization and hopefully traction bars in place if you are worried about wrap up. Four bar links do not move at all. So, no need there.

68ssconvertible.....you are wisdomic in your post with one exception. "I think the tranny pointing up is more common, but sometimes it points down" This statement is incorrect. Most,if not ALL engine driveline designs are pointing the tranny down at the rear. There are several reasons for this. One is that it gives gravity a chance to work with the lubricant return mechanisims and cooling passages to natually expel air. All longitudinal mounted engines that I know of drain oil to the pan visa via gravity with oil flowing back and cooling systems (water jackets in the blocks and heads) to expell air with a planned downward plane in back. Also, note that most intake manifolds have built in corrective leveling angles of 3 to 4 degrees to allow the leveling of the carb. Some modern engines have as little as 2 degrees down in back.

GDV350SS....you are absolutely correct. Stock positoning of the Camaro should be found at 4 degrees down in back. Of course modifications that many throw in could alter this, but I have always found 3 to 4 degees down in back. This was the GM specification as well for all V8s longitudinally mounted to date except fuel injection cars which is 3 degrees. Your vibration is coming from mismatched angles for sure, I would bet on it.

Hope this helps!



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STEVE JACK
ConceptOne Pulleys and Brackets
Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
Techical forum/links at www.inccn.net/techforum.htm


[This message has been edited by HOTRODSRJ (edited 08-16-2002).]
 

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Steve, thanks for the explaination.
I'm setting mine up for street/strip, with more concern for streetablity, so i did mine to GM specs.
I'm going to be using leaf springs in there stock mounts. If i find traction to be a problem i will be using Cal-Tracks.
 

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HOTRODSRJ (Steve Jack)

Great post! Thank you very much for taking the time to share your knowledge. I hope now that I can finally eliminate the vibration I picked up when I replaced my 8.2" open rear with the 8.5" posi rear last summer. I also checked out the link to the inccn.net site. Lots of great info there, especially in your "Jack Stands".

Your '57 and '69 look great also.

Thanks again!!

------------------

'69 SS clone 350/M-20
'65 327/275 Corvette Coupe(previously)



[This message has been edited by GDV350SS (edited 08-15-2002).]
 

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so guys, the sensus is have pinion on rear axle 3-4 degrees down??? getting ready to weld my new camaro spring perches on and would like to make sure i get them on right so i have no vibration, now do i level rearend pinion, then make it go 4 degrees downward and then weld my perches on??? please help, thanksalot
Jake
 

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BB...unless you are specifically building a race car for drags, the consensus is to have the pinion pointed UP at the same angle your engine crank centerline is pointed down in back for optimum set up!



------------------
STEVE JACK
ConceptOne Pulleys and Brackets
Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
Techical forum/links at www.inccn.net/techforum.htm
 

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Does anyone know wear I can buy some shims to use in re-adjusting the rear pinion angle. (I don't want to cut off the perches and re-weld) I've heard that they are available-but I don't know where to look for them. I could take the time and machine some I guess, but I'd rather just spend the money and get some ready to put into place.

Thanks
 

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I have noticed a vibration in my drive line or the tail housing of the transmission (Muncie four speed) at speeds of around 80mph+. The noise starts when at a high RPM in third gear and continue on when I shift into fourth all the way up to 5500 RPM. At around 4500 RPM in fourth gear, the vibration smooths out, but doesn't go away. I was going to replace the output shaft bushing this weekend hoping to cure the problem. Could the vibration be due to mismatched pinion/output shaft angles? How do I check the angles?
 
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