Clutch problems

[Joe]

Background: 1997 240sx, RB25DET engine, RB20DET trans. new clutch: RPS organic, resurfaced flywheel.

problem: on an UPSHIFT there is a fast vibrating noise, not a grind. anything over 1500rpm when the car is warm. it gets worse as the car drives more. it is NOT A GRIND. the sound happens as soon as i go out of one gear then engage the out of neutral into the next. the noise happens for around 1 second and usually stops just after i release the clutch. after i drive for a while when pulling away from a lght the clutch does not slip anymore. it feels like im just launching the car.

ive changed the slave cylinder, adjusted the clutch till my fingers were blue and tried every remedy i can think of. ive pulled the engine for an unrelated issue (emissions..) and have pulled the trans. the clutch appears to be wearing perfect, very minimal grooving on the fingers of the clutch (looks normal to me IMO) and the throwout bearing looks fine. thats all ive had time to sit down and look at since the car is not with me here in phoenix and i had to get home. i think its a problem with the input shaft bearing since the RB25 was origionally an automatic and i put a manual trans on it and did NOT replace the ISB. anyone have any ideas?

just looking for anyone else that has had this problem, i cant find anyone and the RB community is pretty limited with people as you understand.

thanks guys

[Joe]

nobody?

[toptechracing]

replace the ISB

Whats an ISB?

[C1rca]

lol

[SloMoe]

I must be missing something, whats so funny? Anyway, back to actually helping you with your problem. Is it only when the trans is in neutral that it makes the noise, or is it when shifting from neutral to the next gear? If its from neutral to upshift, then synchros maybe? Does it do it when downshifting?

[Joe]

I must be missing something, whats so funny? Anyway, back to actually helping you with your problem. Is it only when the trans is in neutral that it makes the noise, or is it when shifting from neutral to the next gear? If its from neutral to upshift, then synchros maybe? Does it do it when downshifting?

I must be missing something, whats so funny? Anyway, back to actually helping you with your problem. Is it only when the trans is in neutral that it makes the noise, or is it when shifting from neutral to the next gear? If its from neutral to upshift, then synchros maybe? Does it do it when downshifting?

ISB is the input shaft bearingits not the syncros, i will be completley in gear, and off the clutch and the noise is still there for a very short amount of time. why isnt it the syncros? becuase its not possible for a transmission to go from 100% perfect shifting and within 500 miles go to every syncro being bad. the syncros only work for a very short amount of time, this sound happens well after the syncros have done their job. also, i already said it only happens on an upshift. not down.
Modified by Kamin at 3:24 PM 9/14/2004