Metric pinion angle ?

[Dirt Racer]

Metric pure stock with stock rear suspension mounts. 9 in ford floater rear. What should the pinion angle be, and is that number referenced from the drive shaft or the ground?

[Fox_hunter42]

no more than 7 degrees, from driveshaft

[Moldymulldoon]

Using pinion angle from a stock 4 link doesnt work. You want the drive shaft almost straight under power. More pinion angle, will waste power, create drag and LOTS of heat. More the angle, the more the universal will move.

[ric78]

Everyone has an opinion on pinion angle on a stock metric chassis. Myself we run 5 degrees measured on the face of the rearend housing or the face of the yoke if the gear is installed. I have wanted to go a bit more as stated above but my driver said it is fine where we are unless I would like to see the driveshaft come out down the backstretch.

[mel4x4]

with stock gm 4 link, the pinion angle should only be set to make the u-joint happy. Has zero effect on traction, and these rear ends change pinion angle only a little with suspension movement. Spicer recommends operating angle about 1-3 degrees, measuring between driveshaft angle and pinion angle, and the u-joint at transmission must also be within .5 to 1 degree of the operating angle of the pinion u-joint. In short, the pinion angle should be within about 1 degree of the transmission output shaft to minimize vibration and maximize u-joint life.

[langdonracing48]

We always run 9* on a dry slick track. i'll back down to 6 or 7* if im on a tacky surface.

[ToddSmith16]

Pinion angle on a stock 4 link doesn't matter.

[DirtRacer9x]

with stock gm 4 link, the pinion angle should only be set to make the u-joint happy. Has zero effect on traction, and these rear ends change pinion angle only a little with suspension movement. Spicer recommends operating angle about 1-3 degrees, measuring between driveshaft angle and pinion angle, and the u-joint at transmission must also be within .5 to 1 degree of the operating angle of the pinion u-joint. In short, the pinion angle should be within about 1 degree of the transmission output shaft to minimize vibration and maximize u-joint life.

Correct info right here. Where the u joint will be running under load and through suspension travel most of its time should match the front u joint as often as possible during race conditions.

[nguyenvinh2]

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