well my tranny has been making a weird vibrating/ grinding noise in first gear only. This happens when i slowly let the clutch out, taking off slowly. it makes a horrible noise, like something is grinding against something. It only happens in first gear. And i noticed a little noise when in neutral, but as soon as i push the clutch in it goes away. help guys. I have a couple of idea as to what it is but iam not certain. pilot bearing/input shaft or throw out bearing. please help

 

I had this EXACT same problem in my 90 240sx. I t started out in first gear and you wouldn't hear it in any other gear. I would, and still do, drift that car and I started out doing that by clutch kicking the car before a turn ( dropping 1-2 gears so it's well in the powerband but leaving the cluth in so the rpms drop to idle, then popping it right before a turn, over torqueing the rear) It's probaly the most abusive thing you can do to a tranny and rear and after awhile the sound got louder in first and now you can still hear it in 2nd and 3rd, getting quieter as you go to a higher gears. It also has that sound in nuetral with the clutch out that goes away when you put in the clutch.

I was told it was the throw-out bearing by some people, but when I asked a shop he said it would make noises with the clutch in, not with the clutch out. I asked him if it was something that had to be taken care of right away and he said no since my clutch wasn't slipping. His opinion was to just get a new clutch put in since they replace all the bearings and wear parts anyway and that would fix the problem. I chose not to get it done.

It's been a year and a half and 20k miles since, and I've had no problems yet, but it's still making the noise. I don't clutch-kick it so much anymore but I do abuse it often on the original clutch. It does make less than half the power of an LS1 though.