Hey all, I have a '99 Tacoma 6 cylinder, 3.4L, manual transmission. 284K miles, had a new clutch put in about a year ago.

With the engine running, in neutral through 3rd gear, there is a repetitive, metallic grinding sound, like schuck...schuck...schuck...schuck, about 4 or 5 times per second while in neutral. Its frequency increases as I increase RPMs. It goes away with the clutch disengaged (pedal down). I can't hear it once I get up to 4th-5th gear.

I put new trans oil in about 18 months ago.

Any ideas?

 

My best guess: bad throw out bearing or pilot bearing. Basically a new clutch job to fix it.