Any one have a simple pinion angle for a 55-57 using coils and ladder bars I think I need to double check mine might be time for a change
It has to be based on what the output angle is on the transmission. That's the only thing that controls it. SPark
ALL depends on how YOU put the rest of the car together. Engine/trans. angle vs. current pinion angle..! May have to adjust one or the other to get good angles out of all three items. Mike
Actually not. If the driveline is centered but the pinion isn't, the vertical driveshaft angles can be zero and the horizontal driveshaft angle would be the 0-1.5* . You're thinking single plane, not both planes.
Driveshaft to pinion angle should be more then 1 degree and less then 3 degrees for the u-joints to work right, a little more or less probably won't kill it unless the front is way different then the rear. They can be vertical or horizontal, just as long as front and back are close to the same angle. Driveshaft to transmission tail shaft is how you measure the front angle, pinion to driveshaft is how you measure the rear, the rest of the car, driveway, or road make no difference. All that really matters, is that the car is ready to drive and all the weight including driver is onboard. Drag race cars are slightly different as they need a slight down angle at the pinion for to compensate for torque wrap of the axle. Under full power the axle is twisted to the correct angle in high traction situations. Street tires don't bite hard enough to need the preload in the driveline.
a lot of 'close but no cigar' info here. The key factor is parallel. The center line of the engine/trans shaft must be parallel with the center line of the pinion. The center lines can be above or to the side or both, as long as they parallel. Measure those first and correct as necessary. They must be measured with the vehicle at ride height with normal loading. Whether the vehicle is level, parked on a hill or raked does not matter. What you are measuring is the relative angles of the engine/trans center line compared to the pinion center line. The operating angles of the driveshaft u-joints are a consideration in that they should be within the recommended degrees of operating range. Up to five degrees should be acceptable in most street driven vehicles. On shorter wheelbase vehicles, especially, a short driveshaft length can result in more severe u-joint angles if the parallel lines are too far apart, such as might occur in a 'lifted' vehicle. Many people advocate running the pinion a degree or three downward from parallel on a drag car, as stated in an above post. It seems to me the advisability of that depends on the suspension type and geometry changes when in motion. For example, leaf springs were notorious for 'wrapping up' upon hard acceleration resulting in rotation of the axle housing and concurrent changes in pinion angle. A ladder bar or other type suspension controls may behave much differently.
"generally" speaking I use the 3 up 3 down method. I try to get the trans at 3 degree's up and then set the pinion at 3 degrees down. With a true drag suspension and stiff coilers, you can use less pinion angle, say 1-2 degree's..