Pinion angle and driveshaft

[69clone]

Hi, I have a couple questions for you all.
First I'm getting a driveshaft built so I am taking measurements on my 69' satellite 440/727 Dana 60.
I also am trying to figure out the pinion angle of the rear and trans. I was told to get the angles correct before measuring so that you can get the proper distance. From what I read you take the measurements using the driveshaft but being I don't have a driveshaft installed how do I go about doing this?
I can tell the rear end angles up slightly in the front while the tail shaft seems parallel with the ground.

Otherwise will the angle really effect the length? I imagine it's minimal if I have to adjust it a degree or two?

 

[Lionized]

Angle will not affect length.
52.07" according to the FSM.
Do you have a FSM?
All length and angles are described in there.

 

[furryfrog]

http://www.racingjunk.com/news/2014/11/18/pinion-angle-and-traction/

 

[69clone]

Well from the seal on the tailshaft to the rear was a hair under 54". I just wanted to check. thanks for the link.

 

[68GTX4SPEED]

Angle will not affect length.
52.07" according to the FSM.
Do you have a FSM?
All length and angles are described in there.

52.07" that's for a Dodge B-body 1968-70 with 727-833 8 3/4" a Plymouth 68-70 727-833 with Dana should be 50.39"

 

[Lionized]

52.07" that's for a Dodge B-body 1968-70 with 727-833 8 3/4" a Plymouth 68-70 727-833 with Dana should be 50.39"

You're right. My mistake.

 

[69clone]

52.07" that's for a Dodge B-body 1968-70 with 727-833 8 3/4" a Plymouth 68-70 727-833 with Dana should be 50.39"

Now that's from the edge of the tailshaft?

 

[68GTX4SPEED]

Now that's from the edge of the tailshaft?

C/C u-joints.

 

[moper]

First, pinion angle can be set without a driveshaft. Pinion angle is the difference in degrees between the output shaft of the transmission, and the centerline of the pinion gear. The idea is to have the pinion "down" because as the car gets under power, the front of the rear axle rises as the leaf springs work. You need to know the angles of both parts. To be "perfect" you need to do it with 1/2 tank of fuel and the driver or their weight in the seat, and the weight on the tires. Borrow a slip yoke and use an angle finder on flat of the ujoint cap bore of the yoke. Then use the same angle finder on the same spot (flat "side" of the Ujoint saddle) on the rear. If the pinion is "up", determine how many degrees you need to add to point it "down" (meaning past even with the output shaft angle) by 3-4 degrees. Buy those shims, put them under the spring perches, and remeasure.
When that's done, using the same slip yolk, slide it into the transmission till it bottoms, then pull it out 1.5" from bottomed. Then measure from the U joint bore rear edge to the to the base of the Ujoint saddle on the rear. That's the shaft length you need. It should be close to the length they noted above but if you've added SS leaf springs or changed the mounts it might be a plus-or-minus situation.

 

[69clone]

Okay I am still confused. I used both an app on my phone as well as an angle finding device. They were marginally different.
I came up with the ground sloped .4 degrees down front to rear. Measuring off the yoke on the rear it point up +5.5 degrees and the trans slopes down -2.0 degrees. Which gives me a positive angle of +3.5 which is far from what I want right? Ideally I want somewhere around -5 to -3 degrees?
I really don't want to cut and reweld the perches unless shims are out of the question since its already powdered coated and assembled.

 

[moper]

Don't use your phone. Ignore the ground. You're looking at the relationship to the pinion centerline and the transmission output shaft centerline. To get to "zero" in your case the pinion would have to go to +2° or a 3.5° swing. The car could be standing on a 30% incline and it wouldn't matter. You measure the two centerlines, then point the pinion angle "down" 3-4 degrees. You won't disturb the powdercoating. You loosen the Ubolts and slip sims under the spring perches and the angle is adjusted. Easy peasy. This should have been done prior to any big detailing but if it wasn't, it can't be helped now. The wrong angle leads to vibrations and/or worn or broken parts.
If the trans is -2°, and the pinion is up +5.5°, you need to go to around -2° on the pinion, or a 7-8° swing. Get some shims and make the change.

 

[69clone]

Don't use your phone. Ignore the ground. You're looking at the relationship to the pinion centerline and the transmission output shaft centerline. To get to "zero" in your case the pinion would have to go to +2° or a 3.5° swing. The car could be standing on a 30% incline and it wouldn't matter. You measure the two centerlines, then point the pinion angle "down" 3-4 degrees. You won't disturb the powdercoating. You loosen the Ubolts and slip sims under the spring perches and the angle is adjusted. Easy peasy. This should have been done prior to any big detailing but if it wasn't, it can't be helped now. The wrong angle leads to vibrations and/or worn or broken parts.
If the trans is -2°, and the pinion is up +5.5°, you need to go to around -2° on the pinion, or a 7-8° swing. Get some shims and make the change.

Thank you, I agree my phone wasn't quite right I just used it to double check I had the angles correct. The degrees I provided were with my angle finder. I agree it would have been ideal to do all this before but I purchased the rear already built which makes me wonder if they could have welded the perches at the wrong angle but I have heard this is typical with SS springs some guys have angle of 9 degree positive. My comment about the powder coating was referring to if thats too much to try to shim and I need to grind them off and re weld them.
Broken and worn parts is what I'm trying to avoid with this car.