Is it my Clutch or transmission??

ONLY for ADVANCED technical discussion about the 240sx!
180fan
Posts: 7799
Joined: Sat Dec 14, 2002 12:16 pm
Car: 89 fastback

Post

benemorius wrote:When the a$$ at autozone tries to sell you GL5 because it meets GL4 standards, TURN AND RUN.
lol well said. well said.


sds14240sx
Posts: 38
Joined: Sat Apr 08, 2006 5:32 am
Car: 240sx

Post

the problem is your syncros ther are messed up the nissand trannys and gearboxes suck. i had the same problem. get a new transmission or rebuild your transmission. also if you are speed shifting your shift forks could be f****D up too. changing the fluid will not do anything. but if you want to try it, pour some friction modifier in first through the shifter.

User avatar
WI_S14_Goldie
Posts: 1027
Joined: Sat Nov 19, 2005 4:51 am
Car: 1995 Nissan 240sx SE, 91 240 fastback LE, 1997 kouki S14, DD = 93 Nissan Maxima
Location: Wisconsin
Contact:

Post

sds14240sx wrote:the problem is your syncros ther are messed up the nissand trannys and gearboxes suck. i had the same problem. get a new transmission or rebuild your transmission. also if you are speed shifting your shift forks could be f****D up too. changing the fluid will not do anything. but if you want to try it, pour some friction modifier in first through the shifter.
What are syncros?? can anybody help me out?

180fan
Posts: 7799
Joined: Sat Dec 14, 2002 12:16 pm
Car: 89 fastback

Post

syncros are the brass parts in your transmission. before coughing up quite a bit, try using a better fluid. Like Benemorious and I were saying from the start, the fluid change might not do a thing, but it could also quiet down the transmission and make it do what it's supposed to for a bit longer.

sds14240sx
Posts: 38
Joined: Sat Apr 08, 2006 5:32 am
Car: 240sx

Post

SYNCROS LINE UP THE GEARS WHEN YOU SHIFT. WHEN THEY ARE WORN YOU GEARS WONT LINE UP PROPERLY AND YOU GEARS WILL GRIND. YOUR SHIFTER CAN ALSO POP OUT OF GEAR, AND YOUR GEARS WILL LOCK OUT.

User avatar
WI_S14_Goldie
Posts: 1027
Joined: Sat Nov 19, 2005 4:51 am
Car: 1995 Nissan 240sx SE, 91 240 fastback LE, 1997 kouki S14, DD = 93 Nissan Maxima
Location: Wisconsin
Contact:

Post

sds14240sx wrote:SYNCROS LINE UP THE GEARS WHEN YOU SHIFT. WHEN THEY ARE WORN YOU GEARS WONT LINE UP PROPERLY AND YOU GEARS WILL GRIND. YOUR SHIFTER CAN ALSO POP OUT OF GEAR, AND YOUR GEARS WILL LOCK OUT.
So basically my transmission's f*cked then right? (if it is my syncros) Is there any way i can fix it other than get a new transmission? And is it just mine or do all KA's have sucky *** gearboxes?

mello151
Posts: 19
Joined: Fri Jan 07, 2005 11:17 am
Car: '91 240sx

Post

My transmission is grinding into Second, but it only does so when the car is cold. After I drive it a couple of minutes or let it warm for a good while I have no problems. What could this be?

User avatar
PantherRacer
Posts: 9408
Joined: Sat Apr 24, 2004 1:32 pm
Car: 1992 Nissan Skyline R32 RB20DET Sedan
Location: The Moorish Throne of Atlantis
Contact:

Post

sds14240sx wrote:SYNCROS LINE UP THE GEARS WHEN YOU SHIFT. WHEN THEY ARE WORN YOU GEARS WONT LINE UP PROPERLY AND YOU GEARS WILL GRIND. YOUR SHIFTER CAN ALSO POP OUT OF GEAR, AND YOUR GEARS WILL LOCK OUT.
Ay Caramba!This happened to my transmission....It was stuck in gear, and the shifter was locked out of the other gears... (5th gear and reverse will not engage at all) I took off the shifter plate and looked in, to me it looked bone dry...and we just put in 2qts when we changed the clutch.

It might be the shift forks aye? how do I get at those? in the bellhousing or what?

I'm gon put up some pics of what I found in tha gearbox now....

So I put in another quart, turn on the car, let it warm up, wiggle the shifter around and after the oil circulated it would go into all the gears. But 5th and reverse still won't engage and there is a grinding sound when the clutch is engaged in neutral.

So, my syncros are gone? or what?

User avatar
PantherRacer
Posts: 9408
Joined: Sat Apr 24, 2004 1:32 pm
Car: 1992 Nissan Skyline R32 RB20DET Sedan
Location: The Moorish Throne of Atlantis
Contact:

Post



nobody knows...how dry it is...

ok, so that red sprocket is SUPPOSED to be sitting there tilted right?

Chukidori
Posts: 828
Joined: Sat Apr 14, 2007 4:19 am

Post

WI_S14_Goldie wrote: So basically my transmission's f*cked then right? (if it is my syncros) Is there any way i can fix it other than get a new transmission? And is it just mine or do all KA's have sucky *** gearboxes?
No your not ****ed. Driving with synchros can be done, it just requires adjusting your driving style.

The main function of synchronizers is to align the dogteeth on the gears to allow them to "mesh" independently of engine speed.

When they go, your gears will grind because the synchros can no longer compensate for your shifting at less than the ideal RPM.

You have to experiment to find the correct shift points, and learn to rev match your downshifts like on a synchroless straight gear transmission.

For revmatching look up Double clutching, and Heel-toe
Modified by Chukidori at 11:09 AM 4/27/2007

User avatar
My RB25
Posts: 722
Joined: Sat Apr 07, 2007 12:57 pm
Car: 1990 Nissan 240SX SE
Contact:

Post

Kinda on/off subject. I've had my 90 for about three weeks now and I've never owned a manual before now, but I've learned from work and I'm pretty damn good. Trying not to sound consieded.

Anway, I always rev match on down shifting and usually hit my upshifts nicely. Does rev matching for daily driving hurt the transmission? I mean I couldn't see how, the shifter gliders perfectly and the car never makes a hesitation.

User avatar
TRBOMOFO
Posts: 834
Joined: Tue Oct 03, 2006 11:13 am
Car: S13.5 built redtop
Location: Denver
Contact:

Post

yeah my schros are off in 1st to 2nd and i just live with the little grind from 1st to 2nd

and i can never go from 2nd to 1st unles im below 10 MPH

User avatar
tiger
Posts: 1250
Joined: Tue May 03, 2005 3:28 pm

Post

dang, seems like some of you guys know a bit about how a transmission works.I just swapped bellhousings on a KA transmission for my SR. when It was on the floor it shifted through gears pretty good .. now that it's in the car... I can only put the shifter in 1st, 2nd and 5th.. 3rd and 4th I can not get in... the car wont go in neutral either... it feels as though the shifter is in neutral but it's not... are my forks screwed up? Could I have damaged them at all ...the transmission has no fluid in it yet and I have not adjusted the clutch yet(it's brand new) the clutch is working fine i guess because I depressed it and a friend was able to turn the motor over by hand but when the clutch wasn't depressed it would start moving forward when the motor was turned over.. stuck in gear I guess... what could be the prob?


Return to “240SX Technical Forum”