Yesterday my '88 4Runner (22RE) started making a random metallic chattering sound when I would engine brake. Then it would start doing it when I was accelerating in any gear other than first. Then it started vibrating at 2500+rpms in any gear other than first. It also 'pops' when I start going in 1st or reverse. Noise and vibration stop in neutral or when the clutch is engaged. Today i had to add 3/4 of a quart to top off the tranny, and I greased everything with Green Grease. The noise seems to have stopped but I still have the vibration.

Any ideas?

 

No ideas?

 

Only thing I can think of is maybe the driveshaft or possibly bearing (other than first gear maybe at higher speeds....)

Good luck