Wanted to mention. If the noise went away with fluid it is not the TB it was a bearing inside your trans. If 5th gear pops out then the trans needs gone through. ATF is what you use in the MTX trans DO NOT USE GEAR LUBE (80/90). Unless you like having no gears in winter and rough shifts even in the summer. The dealer actually recommends the mopar synthetic, but you can use ATF for a substitute. I have also use purple royal syncro max manual trans fluid and it worked well.

One more time. Do not use gear lube in the trans. ATF is fine. Same with dodge transfer cases, no gear lube! ATF all the way.

 

I use 80/90 weight manual tranny gear oil in my manual tranny in California all year long with no problems with shifting. My Neon shifts fast and smooth with no problems and no missed shifts.

Only problem which is fairly common with any small car high mileage manual tranny, is 5th gear pops out after bearing is worn out. According to the top mechanics, the 5th gear bearing wears out faster than the other gears because of engine load at highway speeds, thus causing it to wear out and then causing it to become loose, then the synchro will not hold its indent, and it then pops out of gear. Over time it gets worse. Other causes possibly are engine mounts loose/broken and also shift cable linkages out of adjustment or loose/stretched.

ATF means: automatic transmission fluid, and Dodge never recommends ATF in their manual tranny's. You can put a thinner synthetic oil in there if you want for cold winters, and you can add a little ATF to thin the manual tranny oil but never fill the whole manual tranny with ATF only. I suppose it would work but it does not have the wear properties and or heavy lubricating qualities of manual tranny gear oil.

 

Uhm, I do believe that Dodge fills Neons with ATF +4. I don't know if it's a general thing, but I do know that '02+ Neons are filled from the factory with ATF +4.