I have a vibration when driving my truck. It was much worse but have since changed the angle of the driveshaft. What is the correct way to setup the angle, taking into consideration that while accelerating the angle would change and the same when slowing down.

Any input will be much appreciated...

Mike




http://www.f100.1965.8m.com

 

Is there a hanger bearing on a '65 driveshaft? Those will cause bigtime vibrations when they are worn beyond limits.

 

no. straight axel drive shaft. all bearing have also just been replaced, so I dont think thats where the problem could be..

 

Have you tried rotating the shaft one bolthole at a time at the
pumpkin, say? Also, sometimes factory installed balance weight(s) will work themselves loose, installing a hose clamp on the shaft as an adjustable balance weight works as a substitute, rotate as necessary.

After all that, could'na tell you about adjusting the angle on the d/s, but seems to me the angle itself shouldn't affect vibe levels.

 

ladewigm,

The correct drive shaft angle to pinion center line is right around
-2 degrees a degree more or less is usually workable unless you have a radical initial drive shaft angle to begin with. We must consider both ends of shaft when calculating desired pinion angle.
It is the diffrence in degrees between trans output & rear end[pinion] input angles.

The output angle (from trans tail shaft) can be more but over 5 degrees can be problematic depending on several variables.

If you establish an imaginary line at level, along center of drive shaft, and call things heading up from, or above line positive, and things heading down from, or below negative, trans output angle would be -5 degrees, pinion input angle would be + 3 degrees. Adding +3 to -5 gives us -2 which is what we want, ideally speaking.

It works that way even w/ a ridiculous - 45 degree output angle & + 43 degree pinion input angle. Difference still is -45 + 43 = - 2 degree difference. . . . I don't know if I made that clear enough?

Your springs shouldn't "S" warp enough to matter, if they do, I suggest you use traction devices, or a center link to stabilize any pinion angle changes beyond a +/- 1 degree [that=2 deg. total] variation.

Traction bars parallel leaf sping & have pivoting ends act as a 4 link set up. This stops pinion end arc-ing or rotation. It will move up/down in a perpendicular, or square plane, to centerline of links.
It's one of reasons reason why 4 link suspension is so popular. another reason is increased forward bite due to better traction.

FBp