Alright so I have searched the great depths of HT and I am a little confused. I want to figure out what's wrong with my trans: Is it the TB or ISB? When my foot is completely off the clutch pedal I hear a rattling noise. When I completely press the clutch pedal the noise goes away. That's not the only thing though. When I'm driving and I downshift, from 3rd gear to say 2nd, I hear a loud whining noise. Could it be both the TB and the ISB? How long can I drive like this?

 

Either way your going to need to replace one or the other or possible both.

So might as well get busy.

 

ISB

 

I don't mean to sound like an *** or disrespect you, but how do you know? Has this happened to you before?

 

 

Like RonJ said, foot off pedal noise = ISB. Foot on pedal noise = TOB. Extremely common problem. Do yourself a favor, if you plan on doing the work yourself, get a factory service manual, and the full rebuild kit (bearings, seals, and synchros) from Syncrotech. You'll be digging deep into the transmission - no reason NOT to replace all of the wear items while you're in there. Your main seal would also be easy to do while you have the transmission off, as would a new clutch disc, and having your flywheel resurfaced.

Of course, that list is just the best idea, best practice list - it isn't all necessary, but I would highly recommend it from personal experience.

 

if it doesn't grind, a synchro kit is completely unnecessary. I would replace all the bearings though, as it could also be a countershaft bearing.

 

input shaft bearing