driveshaft angles

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So what is the pinion centerline deg if the trans centerline is 2 degs down?
 
Okay.
But my factory untouched housing was 5° down, and needed two degrees more down to get it where I want it after a ss spring install. If it WERE 5° up, I would have had a he'll of a time finding 12° shims......
if the spring perch is 5 degs up mounted the pinion would be 5 degs down
 
When you set your pinion at 5 degrees, is that measured relative to the ground? If not what is the 5 degrees relative to?
I've already answered this once. It's relative to the ground. I weld the perches on so the pinion center line is 5 degrees up relative to the ground. That is the ONE TIME when the ground is relevant. After that, it doesn't matter where the ground is, or if the car is flipped upside down, backwards or inside out, because from there you are measuring working angles of the u joints.
 
So with rear end out of the car and the spring pads level to the ground the front of the pinion is angled down 5 degrees relative to the ground?
Yeah, because you set it up with the rear axle upside down so you can get to the perches to weld them on, so you're actually pointing the pinion 5 down. Once flipped right side up and installed, the pinion has a 5 up angle built in.
 
Yeah, because you set it up with the rear axle upside down so you can get to the perches to weld them on, so you're actually pointing the pinion 5 down. Once flipped right side up and installed, the pinion has a 5 up angle built in.
So when you say you always set your rear ends with the front of the pinion pointing down toward the ground at a 5 degree angle relative to the ground this is with the rear end upside down?
 
So when you say you always set your rear ends with the front of the pinion pointing down toward the ground at a 5 degree angle relative to the ground this is with the rear end upside down?
Yes so I can get to the perches to weld them on. Once right side up, the pinion is 5 up.
 
Yes it is! With this Ford 9" I am building to go under Vixen for example. I did the same with it that I do with any other rear axle starting from scratch. When locating the perches, I get the location and width correct and then rotate the housing so the pinion ends up 5 degrees nose down and make my welds. Done many like that and they turn out spot on every time.
I didn't see here where the rear end was upside down when you measured it.
 
I didn't see here where the rear end was upside down when you measured it.
Because I didn't include it. Do it however you want. I know the way I've been setting them up almost 40 years works. One more time. This is all covered in the MP chassis and suspension book. Just like all the engine information is in the engine books. I never have understood why some Mopar guys refuse to get copies of those books. They were the first publications I bought when I got serious into Mopar. It seems like some guys dig their heels in even harder against getting them whenever some of us make the recommendation. I just don't get it.
 
Because I didn't include it. Do it however you want. I know the way I've been setting them up almost 40 years works. One more time. This is all covered in the MP chassis and suspension book. Just like all the engine information is in the engine books. I never have understood why some Mopar guys refuse to get copies of those books. They were the first publications I bought when I got serious into Mopar. It seems like some guys dig their heels in even harder against getting them whenever some of us make the recommendation. I just don't get it.
Sorry if I ruffled your feathers. I know you are trying to help. But you can see where a person could be confused or mislead by your post. I think you would agree the part about the rear end being upside down was key to the information you provided. Nobody is perfect. We all make mistakes. I believe currently I hold top score in that category. xxxooo
 
I think he is referring to the factory setting. Mopar welded the spring pads at a nose-down 5° angle, to account for the angle of the front segment of the leaf springs.
The angle of perch on an a-body is angled down, if you set the perch level it 5 degrees UP, in other words its 5 degrees different,
see picture with the line from front to back spring attachments. That’s the angle the housing perch is welded at so the housing-pinion is parallel to drive shaft at rest. When at rest the spring is not arched but designed to be flat when going down the road

14547D6B-C62F-45EF-B8F5-ABA57FB090F1.png
 
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damn,...look at it this way, each u-joint needs to be equal degrees but opposite pitch from each other!! add a degree or 2 to rear if racing! yall thinking toooo much, need to get outta ya own head a lil bit!! way i do mine is on level ground put cinder block under each tire so every thing at ride height!! set trans output shaft up 3 degrees then set pinion down 3 or so degrees, wield ya rear end perches,..then send the bish!! now if ya working on a big truck that takes a totally different approach!!
 
Sorry if I ruffled your feathers. I know you are trying to help. But you can see where a person could be confused or mislead by your post. I think you would agree the part about the rear end being upside down was key to the information you provided. Nobody is perfect. We all make mistakes. I believe currently I hold top score in that category. xxxooo
No, not at all. I wasn't directing any of that at you at all. Sorry if it came out like that.
 
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