Hello,
I've got an '85 4x4 pickup with a 22R and 5 speed. I've been working on fixing some driveline vibrations.
Should there be any slop in the transfercase output flanges, 3rd member flanges, or slip shafts?
Some background: I've got 3 1/2" of suspension lift no thanks to NWOR. It's probably sagged about 1 1/2" by now. Anyway, I've had the lift for about 10 years and the driveline used to be nice and tight, and now it's starting to wear out. The first and most obvious thing I fixed was had the front driveshaft slip shaft replaced. It was the most sloppy (about 1/16 to 1/8" wiggle in it). My rear driveshaft slip shaft also has a bit of side to side wobble in it, but not as bad as the front. The slip shafts wore out becuase the useless driveshaft boots that I also bought from
NWOR (I was young and stupid) trapped in all the water, dirt, and salt rather than keep it out. The U-joints all seem to be nice and tight, including the CV joint on the front shaft. I replaced the crappy two-piece rear drive shaft with a stock single piece from an '88 pickup many years ago because I went through 2 center bearings rather quickly with the lift.
I have very little vibration from the rear when in 2wd with the hubs unlocked. As I mentioned, there's a slight amount of play in the slip shaft. The t-case output flange has about 1/16-1/8" slop and rear 3rd member pinion flange has maybe 1/32". I've already tightened the 32mm nuts and re-whacked the nut.
Most of my vibration is coming from the front driveline. When I lock the hubs, a driveline vibration starts around 40mph and is noticable the rest of the way up and varies in frequency and amount based on vehicle speed. If I shift into 4wd, it's even more noticable. The front driveshaft slip shaft was just replaced, and they replaced the front section of the driveshaft to include a new U joint too. The CV joint is nice and tight. It was balanced and painted and looks like a new driveshaft (I was impressed). There's NO play in the slipshaft. The output flange on the transfer case has about the same amount of slop as the rear output flange on the t-case, and the front 3rd member flange has about 1/16" slop. Like the rear driveshaft, I've already tried tightening the 32mm nuts. I've also tried unbolting the front driveshaft and putting it back on, on a different position on the flange.
Both driveshafts are assembled in phase properly with the zerks pointing the right way. I'm positive it's not tires or some other thing causing vibration (problem goes away for the most part with hubs unlocked and in 2wd). The frequency of the vibration is too high/fast to be shaking 33" MT's.
Should there be any slop at any of the locations? Could any of this have to do with the fact I'm running a stock V6 4.88 3rd in the rear and a 4 cylinder 3rd up front with aftermarket 4.88's? (I just posted another thread about it being stubborn to shift from 4wd back into 2wd now that I've removed the stock 4.10 3rds).
