can i check angle by checking back end and front end before bearing caps on drive shaft with out pulling drive shaft now reading 0 degree on each end ............
That could work. We can kind of guess what you mean by what you're saying, but a sketch of it would make it more clear.
Put your angle finder on your drive shaft, record that number, put it on the flat spot behind your rear end yoke, or with the yoke turned so its flat, you can put it there, and record that number, the total should be 5⁰-10⁰ no more than 10⁰, I believe 7⁰is optimal
With your car sitting normally on the floor, check the angle of the driveshaft. Then remove your driveshaft and check the yoke on the rearend and the rear of the transmission. Pulling the driveshaft ain't that hard if you want to do it right.
Measure the driveshaft angle at the transmission end, then measure the transmission or engine oil pan flange, or use a u-joint cap. You are looking for 3 degrees +/- of working angle. That's the difference between trans angle and driveshaft angle. Then do the same at the pinion, rotate the u-joint so the caps on the pinion side are vertical, you can measure off them. If there are no u-joints to use, you might need to to pull the driveshaft to get to a flat surface on the pinion. Again, you are looking for the working angles, 3 degrees difference between the two.
If you’re having trouble visualizing what’s been said, spicers website has drawings explaining things.
You can ball park pinion angle when you build the car but to get it exactly you are going to have to have the full weight of the complete car sitting on the tires or on the axles sitting on stands. True there most likely are chassis builders who have built the same chassis setup times over who can get it right when they assemble the chassis without a body on it but that is from experience. Us guys who only do one every five years or once in a lifetime have to do it the hard way after ballparking it. When all is said and done pinon angle has to be on the same plane as the output shaft angle. Don't listen to those damned 60's Ricky Racers who claim you have to have the pinion angled down to compensate for "torque" they are still around offering advice that was bad then and is still bad. I'd attribute a number of U joints that got blown on the line to that concept.
The 0* angle is cool however, if the transmission is 6inches higher than the rear, then we gotta talk. . .
This topic comes up often. There seems to be a variety of opinions and some people swear by their method. Even the people in the driveshaft, universal joint, rear end assembly industry disagree. Sometimes they agree but their method of explanation is so different that they seem to disagree. I have my own method that works for me. Recently I built an off topic vehicle that because of the rules for competition,(I could not cut the floor or the firewall) I had to install the engine and transmission at angles that I thought would never work. However, it does not vibrate, it has many passes on the drag strip, and several thousand miles on the highway. I do not know who is right, but I do know that if something works for you, stick with it.
Exactly. I've always been told that 10 preachers would give you 10 different interpretations of the Bible, and it's true about everything. I was taught that with coil Leaf springs you wanted your pinion pointing down a couple of degrees, so that under torque it would come up level. Another fella taught me to check the driveshaft and pinion, add them together. I always do it that way. I guess you need the angle to cause rotation in your u-joint caps for lubrication purposes. And zero angle means that doesn't occur.
The Jalopy Journal
