Stupid Noise from drivetrain!

[Vision Garage]

Okay so I changed out my tranny on my s13 and all was good. However, when i drove it, the car would make this weird humming whirring noise from either the tranny, driveshaft or diff.

I cant figure out what it could be. when i start the car in neutral and gas it, it revs fine. No noise whatsoever. But when i throw it into gear. Mainly 3, 4, and 5, it starts to hum and make noise almost like an alternator going bad.

What do you guys think it is? ill post a video on it later.

Pilot bearing and release bearing are probably not it since it doesnt make any noise in neutral or low rpm.

[Vision Garage]

No one has any idea?

Sounds like this

YouTube - Throwout bearing (http://www.youtube.com/watch?v=EFic7mA4gr4)

or this

http://www.youtube.com/watch?v=7BMxPtAwSw4

[SoguRacing]

well, do you have any bolts flopping around in the bellhousing or something loose? I know i get a humming noise from my diff when I decelerate. I think it wearing out or something. 4 years on it...must be.

are you sure the tranny you swapped out was a good tranny?

[Vision Garage]

well the seller said it was a good tranny. Cant really say how good a 15-20 year old tranny is ya know. Just wanted to see if anyone had this problem before. and what woudl cause it. throwout bearing, pilot bearing, input shaft bearing or what not.

[neilsan]

You put in fresh oil, right? of the correct weight, GL-4 ONLY and the correct amount?

When exactly does the sound occur? only when shifting, or does it make noise while in gear? Does the sound change with vehicle speed, or does it change with engine speed?

Did you replace the clutch or release bearing when you swapped transmissions?

Sogu, how is your diff only 4 years old? If you installed an LSD but didn't have the pumpkin overhauled with a new pinion depth crush sleeve and new shims then for all intents and purposes it's still 15 years old. Every one of my S13's has had a loud diff, especially on decel. Also amplified by subframe collars. My S14 makes it too but it's not as loud because i've got peak urethane collars instead of metal and obviously s14 diffs are mounted to the subframe with bushings too but I still hear it. i'm sure that after 10 years the runout gets out of tolerance but i just consider it a "240 thing" because i haven't had a diff fail on me yet.

[Vision Garage]

No i reused the same ones since they were fine on the other car. Sound does not occur in nuetral and revving. Only when car is in motion at higher speeds. Higher gears 3 4 and 5 make the noise and it gets louder as you gas it more. If i take my foot off the gas to cruise it wont make any noise. Only when i gas it.

[neilsan]

then its not the release bearing or pilot bushing. If it's load dependent and at higher speeds my initial thought is to make sure you're not leaivng a puddle of oil when you park from a possibly bad front or rear seal. Obviously low oil means poor lubrication, and that will be most prevalent at high speeds and high load.

Did you drain and replace the oil that was in it? If not, or if you used anything but a quality 75w90 GL4, then before you do anything else I would recommend first getting some Amsoil (http://www.worldsbestoil.ca/GL4-Synthetic-Manual-Transmission-Lube.php) or Redline (http://www.redlineoil.com/products_gearlubricants.asp?productID=46&subCategoryID=17&categoryID=7) synthetic oil. If you used oil that was rated GL3/4/5 then the sulfur content is incorrect for the gearbox. It needs GL-4 only.
My friend tracked his car with cheapo brand mineral based 75w90 in the gearbox and it started making noise and not shifting properly after a little while. AMSOil fixed that. I personally prefer it to redline but redline is easier to find at a store.



probably not input shaft bearing since it wouldn't matter what gear you're in because the input shaft only spins as fast as the engine.

[DataXUnknown]

Check your driveshaft. Make sure all the rubber (up near the entrance of the transmission) is all in tact and all bolts look fine. Just inspect the basics first.

[joshy240sxxx]

could be bearings you should bleed a little oil and see if there are any colored flakes in it. if its silver could be gears or bearings and if its gold blocking rings. sorry if this is already answered to lazy to read but drive it and then coast in nuetral and if noise goes away that rules out driveshaft and diff .. but if it still does check the alignment of driveshaft. or the angle

[joshy240sxxx]

also if the clutch and everything was fine on the tranny doesnt meen it will be fine with your flywheel they are both worn differently.