Topic: Message #1145040

[1980firstgen20r]

1980firstgen20r,

What do you think is causing your vibrations?

When do you feel the vibrations?

If the vibrations are caused by out of phase U-joints or driveline angles, it’s usually a fairly straight forward fix.

If the vibrations are caused by bad U-joints, or pinion bearings, they usually can be detected by checking for excessive movement.

Some axle wrap is normal.  Excessive axle wrap may occur  on heavy acceleration, braking, and on the trail while applying lots of throttle torque, like rock crawling.

https://www.drivelinesnw.com/part-trouble-shooting/vibration-analysis/angle-analysis/measuring-and-correcting-angle-problems/

https://www.4wd.com/p/pro-comp-degree-shim-99-200/_/R-DFCW-99-200?utm_source=google&utm_medium=cpc&utm_campaign=shopping&emlprox=out&ppcfon=1&gp=1&scid=scplpEXP99-200&sc_intid=EXP99-200&gclid=EAIaIQobChMInefJv_rO1QIVgYl-Ch18MgRZEAQYBCABEgLnsPD_BwE


Gnarls. 

I believe what's causing the vibration/ gear grinding noise is the drive shaft being out of parallel. The u joints are brand new. Had the guy at the drive shaft shop replace them when I had him shorten down the shaft to accommodate the w56. And the vibration/ noise happens when I'm in 2WD driving on the pavement. In 4WD the noise isn't bad at all.
I also Checked the play on the ring and pinion when the original axle was in the truck and it seemed fucked up to much play. So I installed a 2nd generation axle that I had already taken apart and rebuilt. So I trust the axle/ ring and pinion. What I don't trust is the rear drive shaft angle being out of parallel. I don't know if I need to point my pinion up or down to make it match the T case angle. I have a few other threads in this category with some more info if your interested in reading them. Getting tired of posting the same thing over and over