The car is a 2002 Civic.

Recently my transmission's been making grinding sounds. After spending quite a few hours and posting in many car forums and receiving all sorts of answers, I think I've finally found out what it is. Input shaft bearing (pilot bearing).

Symptoms: It makes the sound in 1st, 2nd, and 3rd gears. 1st is the worst, 2 is a little bit better, and in 3rd I barely hear it. When the car is still, I hear a little bit of friction noise, but when I press down the clutch pedal, the sound goes away.

My question is this: If it's the input shaft bearing, shouldn't it make the noise in all gears? Why only 1st, 2nd, and 3rd gears? Why is the noise different in neutral than in gear and moving?

I have a good knowledge of car engine and transmission (I worked at a mechanic shop for a year just for fun), so don't hesitate to throw technical terms at me.

 

Pilot bearing and input shaft bearing are 2 different things. Pilot bearing goes in the flywheel, ISB is in the transmission. Actually there's 5 bearings in the transmission that could be making noise. Only making noise in the lower gears is common btw.

 

Have you drained the MTF and inspected it for metal debris? That would be a good indicator if it's an internal issue. I've seen the ISB in these transmissions fail before, and it's not pretty. It'll also leave a fair amount of debris in its wake.


In any case, you're going to have to roll your sleeves up and get your hands dirty if you're going to save yourself some funds. Or consider the option of buying a rebuilt transmission. I've seen them sell for $400 including a 2-year, 20k mile warranty.


Best of luck with it.