Background: Gen 2 RB25det into a 1997 240sx. engine was an automatic but was given a manual flywheel(do not know if it is a rb20 or 25), used clutch and RB20 transmission with my clip. resurfaced the flywheel and put a new RPS Max full face clutch on. new throwout bearing. (did not change release bearing first time from the automatic to manual.)
about 3 weeks after finishing the swap i start to hear a noise that can only be described as a deep vibrating noise in higher rpm when shifting. it gets progressivley worse as i drive the car and at a certain point the car becomes undrivable. the clutch does not slip, only workslike a light switch, on or off. adjusting the pedal does not change anything, flushed the transmission, nothing. this was about a year ago, i was forced to park the car to finish school because i had no time to work on it
i moved home about 2 weeks ago because i graduated school, i swapped the KA back in for emissions, passed, had the RB back in a couple days ago. this time i removed the auto pilot bushing and put a real 5 speed one in thinking that could be the problem. after hunting down some wiring problems the car was running beautifuly. no issues. for about 30 minuets. then the noise comes back.
when sitting at idle, pushing the clutch, no noise. if i push the clutch then try to engage a gear i get this noise. low deep vibrating that follows engine speed. it does not affect my shifting. i can go into gear smooth as ever while it makes this noise then release the clutch and it goes away. this has happened in all gears, at almost all times. ive even had the noise while free revving at idle and pressing the clutch at a high rpm.
right now im extremly frustrated, and have no idea what this problem is. the clutch, flywheel, TOB all looked completley normal while i had the RB out from emissions and to install a manual pilot bushing because i thought that was the problem. im at the end of my rope with this problem, im about to just ditch the transmission and get a new clutch and flywheel. the right ones.
Drivetrain problems. (long, serious issues.)
Re: Drivetrain problems. (Kamin)
after driving it a little more today (another 45 minuets of street driving) ive got some more info.
it makes the noise in neutral when revving, sometimes. about 50% of the time, same with pulling away from a stop. not all the time.. almost every upshift under normal driving and "spirited" driving makes a quieter version of the noise. it has NEVER made the noise on a downshift.
it makes the noise in neutral when revving, sometimes. about 50% of the time, same with pulling away from a stop. not all the time.. almost every upshift under normal driving and "spirited" driving makes a quieter version of the noise. it has NEVER made the noise on a downshift.
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goofynick6
- Posts: 1216
- Joined: Thu Feb 05, 2004 9:58 am
- Car: 1995 S14.5 RB20DET
I'd say it sounds just like my car did...
My engine was from a Cefiro, and automatic before, so it had auto pilot bushing. I installed the manual trans, but didn't swap bushings (didn't know better). Could go into gear sometimes, but would grind and make noise.
Took it apart, pounded in the manual bushing, but pounded it too far, and the car didn't shift into gear because at the end of the crank where the bushing goes into, there is a step and it crushed the bushing down and pinched the input shaft.
I pulled it apart a 3rd time and put a new bushing in, tapping it in carefully with a plastic tool, and made sure the clutch alignment tool slid in and out smoothly before bolting the trans up...now it shifts awesome and doesn't make any noise.
HTH,
Nick
My engine was from a Cefiro, and automatic before, so it had auto pilot bushing. I installed the manual trans, but didn't swap bushings (didn't know better). Could go into gear sometimes, but would grind and make noise.
Took it apart, pounded in the manual bushing, but pounded it too far, and the car didn't shift into gear because at the end of the crank where the bushing goes into, there is a step and it crushed the bushing down and pinched the input shaft.
I pulled it apart a 3rd time and put a new bushing in, tapping it in carefully with a plastic tool, and made sure the clutch alignment tool slid in and out smoothly before bolting the trans up...now it shifts awesome and doesn't make any noise.
HTH,
Nick
Re: (goofynick6)
how deep did you pound it in when it was too far?
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Yellow4g63
- Posts: 3718
- Joined: Mon Jan 20, 2003 6:07 pm
- Car: 95 Nissan RB20 240SX RB20
91 Nissan NX2000 VE power
95 Nissan 240SX Stock - Contact:
Re: (Kamin)
[7th grade] LoL pound it too far lol [/7th grade]Kamin wrote:how deep did you pound it in when it was too far?
Re: (Yellow4g63)
haha ok i didnt do that
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Phat_Optimo
- Posts: 183
- Joined: Tue Jun 10, 2003 5:36 am
- Car: 93 S13 SE
Re: (Kamin)
Sounds like its a main shaft bearing problem. Seems to me that you have eliminated any possibility of it being in the bellhousing. Sorry to hear the bad news.
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FAST-DATSUN
- Posts: 1019
- Joined: Tue Oct 22, 2002 9:46 am
- Contact:
Re: (FAST-DATSUN)
I will do that Mack.FAST-DATSUN wrote:call me after 4:00PM to discuss the problem..
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goofynick6
- Posts: 1216
- Joined: Thu Feb 05, 2004 9:58 am
- Car: 1995 S14.5 RB20DET
Re: (goofynick6)
Mack makes good sense hehe, here is what it sounds like the problem is
the input shaft bearing wasnt alinged properly while the auto bushing was in (the auto bushing is a larger diameter) so every time i pressed the clutch the input shaft could essientally move around and sideload the bearing. thats why this problem didnt arise for some time after the origional install. and thats why my auto input shaft bearing has knicks and pit marks all over the middle of it.
the input shaft bearing wasnt alinged properly while the auto bushing was in (the auto bushing is a larger diameter) so every time i pressed the clutch the input shaft could essientally move around and sideload the bearing. thats why this problem didnt arise for some time after the origional install. and thats why my auto input shaft bearing has knicks and pit marks all over the middle of it.
Re: (goofynick6)
Also, even if the pilot bushing isn't put in all the way; upon installation, the actual transmission input shaft will "nudge" the pilot bushing into the correct spot. This was an actual trick on the older Nissan KA pickups. The aftermarket pilot bushings were too small in diameter by about 1/100s of an inch. If you nudged it in too far, as Kamin has, similar problems would arise. So, the trick was to put the pilot bushing in almost to where it had to go, install the transmission, and let the input shaft nudge it in with the transmission "pops" on.