Thread: Adjusting pinion angle w/4 bar rear end

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When running 4 bars, the pinion should tilt up the same number of degrees that the transmission points down. Most v8 engines are set up so that when the carburetor base is level the tranny tailstock will angle down 3 to 3 1/2 degrees. To keep your wheel centered in the wheelwell,for every full turn that you shorten the bottom 4 bars, then lengthen the top 4 bars the same amount, or vice versa. To have the tranny pointed down and the pinion pointed up is absolutely wrong---that setup is only for drag racing, when wrap up in the springs, 4 bars, and yes, even the frame, will bring the pinion up to level. This is absolutely the only time a pinion should point down---full on drag racing.

Originally Posted by brianrupnow

When running 4 bars, the pinion should tilt up the same number of degrees that the transmission points down.

This is what I've always heard too... I've never heard of aiming both the pinion and the trans downward, unless maybe you're building a drag car thats gonna be launching at 9k or something. Right now it appears my trans points down, and my pinion points up, but I believe the pinion angle is greater than the trans angle, necessitating a slight tilt downward to the pinion. That "angle locator" posted above is actually a protractor similar to the one I am hopefully borrowing this week to determine my exact angles, but as i said, visually right now, I'm gonna say my pinion needs tilted down a bit. I wasn't sure which bars i needed to adjust, but it sounds like if I want my wheels to stay where they are, i need to adjust top AND bottom bars.