Okay, finished all of my welding on the rear, and now that I am looking at the pumpkin, it is level. From one angle, it looks even slightly down. Just clarifying here: the trans shaft and the pinion shaft are to run parallel with one another, correct? In other words, when I did the final welds, I ensured that the trans tail and the pumpkin yoke were both on the same plane (and they are). Someone please clarify. Pork
If you have a Smartphone, get the Tremec Driveline Angle Finder App (it's free!)-it is for checking these angles-it checks three angles in relation to each other (Crank, Output Shaft & Rear Axle Yoke)-it is really easy to use, and you can re-check very easily- http://www.tremec.com/menu.php?m=154
Trans down 2 to 3 degrees will set the carb level, pinion up 2 to 3 degrees will give you equal u-joint working angles at each end of the driveshaft. Pinion and trans do not need to be parallel as long as the u-joint angles are equal. You can have trans down and pinion up or pinion down, just be sure they both are at the same number of degrees. Get one of the cheap-o angle finders, they make it very easy to figure out. Be sure to take into account the weight of the vehicle as the pinion angle will change once loaded. U-joints must have a couple of degrees in them or they wear out extremely fast.
Yeah, the need to be in the same plane, when under load. If it has leaf springs, I like to point the pinion down a little (one degree or so) relative to the trans, so it will be level when it "winds up" under load. If it has a more positive locating type of suspension, like a 4 link, then this is not needed.
...yup, best to set up your rear pinion angle with all the weight of the car on it's wheels & tires...
"3 up, 3 down and nobody gets hurt". Forgot who the batter was that was describing a good night at the plate against Nolan Ryan, but it makes it easy to remember. Comments above about drive height and weight are correct.
Currently they are both 4 degrees (parallel). I will drive the truck like that and see if I get a vibration. If not, she stays as she is. If she shimmies, I made the rear and the trans mounts "shimable." Currently the trans shaft is slightly higher than norm, but I set it up that way. I can't stand the bent in the middle look that a lot of cars at shows have. I know such will "throw the carb out" but I have yet to have idling or running issues during twenty minute test runs. Pork
I run a constant velocity joint (Double Cardin Joint, for those who speak "drive-shaft". What angles should I seek? I understand the rules change.
nice treatise on Constant Velocity U-Joints; https://en.wikipedia.org/wiki/Constant-velocity_joint 2many mentioned the Double Cardan joint. I recall working on a 50's Buick that had that type of joint. There was some kind of ball & socket in the middle of it to "maintain equal angles between the driven and driving shafts for true constant velocity rotation" per Wiki. What I remember most about it was that is was a major PITA to get apart and back together because of that centering element.
CV joints are Not the same as Double Cardan. True CV joints look like this, and are properly known as Rzeppa Joints Double Cardan's look like this These days many folks improperly call Double Cardan's C.V. joints and that isn't correct. They operate differently and need to set up differently. If you have a Double Cardan, the right way to set it up is like this.
Best driveline angle and phasing explanatory video ever. Not my original post, it was mentioned a year or so ago on another thread but I copied it to my desk top for reference. Creds to the OP of this video.
The Jalopy Journal
