So yesterday I noticed a very weird vibration when driving my D1. It doesn't do it, to my knowledge, when I accelerate. But if I am just cruising at 35-45 in 5th, there is a definite vibration. If I pop it out of gear and coast, there is no vibration, if I let off the gas in gear the vibration goes away and if I give it MORE gas (by pushing the pedal further) the vibration also disappears.

As far as work recently I mounted a push bar, flushed my front diff with Royal Purple, and did right side caliper, pads, rotor, bearings and seals.

I honestly have no idae where to start.

Thanks!

 

Sounds like a u-joint to me.

 

Also, at highway speeds it is not there. I remember the PO telling me he changed the drive shaft to one from a ~98 D1? Would that make sense? I emailed him either way.

 

I would think U joint as well but its a tough one, I would try getting under the truck and rocking it back and forth in gear (I lay on my back and push the car forward with my feet)to see if the ujoints have any slop in them, often you will see a little play when the vehicles weight shifts if they are warn.

 

That's a funny image in me head I'll give it a try.

 

X3 on the U-Joint.
Although, with recent brake work, you might want to bleed them as I have had strange things pop up when I have had air in my lines...