Gtr Gearbox Crunch?

[abu]

Hey

Was giving my GTR a bit of a hard time yesterday and now there seems to be a slight issue with the gearbox/clutch engaging

I put the clutch into the floor and when I attempt to change gears it crunches, much like when the clutch isn't engaged

Clutch doesn't slip, not even on high RPM or launching but its starting to crunch 4th gear now even on low RPM levels

I thought it may be the slave or master cylinder leaking pressure and not providing enough clamping pressure on the pressure plate to clutch, causing it to crunch but my dad checked both and it seems neither is leaking

Fluid looks clean with no leaks, according to service records the fluid has been recently changed

Any other thoughts or ideas on what it could be causing the problem

Thanks

[Julz89]

could have air in the clutch hydraulic system also try changin ur gear box oil u find that it be smoother

[trel]

what was it?

[bozodos]

yeah curious as well, my stagea box is doing the same thing after some spirited driving last night, crunches 4th a lot, really freaked me out, you didnt put some Redline oil or something in it?

[abu]

Okay, well I thought I had it all sorted but it has started happening again

I topped up the fluid as it was a little low, pumped the clutch with the lid off and then tried again and it was fine for a few days, now its started doing it again on the odd occasion

Sometimes its fine then on randomly it will crunch into 4th for no reason

Does anyone know what the fk is up with it??

I'm going to drain the clutch fluid and put new fluid in it next week, then bleed the clutch. Hopefully that does it but some how I don't think its that as the clutch seems to work fine, no slip or anything and grips in every other gear

Thanks

[abu]

No one knows why?

[rhys5169]

im the same when i change gear into 4th when im boosting, was just gonna replace the gbx fluid and give it a try :s

[abu]

hmm pretty sure mine was replaced recently

I'm going to bleed the clutch tonight and see if that makes a difference

[femno]

It wont. If it was the clutch it would crunch all gears. No?

Dude its 4th synchro, theyre dynamite for crunching. Redline doesnt help either. Its not as miraculous as most say...

Might as well start looking for a new box lol, thats what I did! Fixed it real good.

[abu]

Yep

It's the 4th gear synchro

[limpus]

Why would it be the clutch? its a synchro for sure...had it happen on so many of my boxes...shift gently and change the oil and hope for the best...its either that or change it...

[abu]

It's happened in the past and it's been the clutch, in a previous car I had it was doing exactly the same thing but it was the pressure plate failing due to being weak causing the clutch not to engage 100% therefor making it hard to put it into gear

Also on the forums the cheap clutches that SLIDE was selling, EXEDY clutch plate and OEM pressure plate eventually started to do the same thing

Thanks

[candy33]

Yeah its the 4th gear syncro, have the same problem on mine and seems to be very common on the gtr's.

Theres no way of fixing it other than replacing box or the gears.

[limpus]

Wound not hurt to give it an oil change with something decent first and see how it goes...and of course try to shift alittle easier...

[abu]

Its got new redline gear oil in it

As I said, it doesn't crunch all the time just on the odd occasion, most of the time it's avoided

[GTS4WD]

I have a GTS4 with a fairly badly crunching 4th.

Why not just try slowing down the speed of gear change?

Double clutch/heel-and-toe gears down.

5th -> Neutral -> 4th

Blipping throttle helps too

[abu]

I have a GTS4 with a fairly badly crunching 4th.

Why not just try slowing down the speed of gear change?

Double clutch/heel-and-toe gears down.

5th -> Neutral -> 4th

Blipping throttle helps too

Yeah that's what I do to avoid it crunching but I'd rather not do that forever

[bozodos]

I found with mine that double clutching did nothing - I noticed however that clutching, bringing the gearstick back slightly and allowing the revs to drop before putting it into 4th makes it smooth again 99% of the time - does not work for downshifts though so I just go straight to third, I'll try some Redline Shockproof Lightweight until ! can get the money together to try and get another GTR/Stagea box!

[dave32gtr]

Hey I know this is off the topic a little. My car use to crunch first at the lights and if you where a little miss timed with the clutch on the gaer change it would crunch. I got my clutch changed because all of a sudden I had a large vibration. I had cracked my flywheel. After replacing it I never crunched again. I think I am lucky my flywheel didn't let go when it finally decided to go. The only thing holding it together was the ring gear. So now I am alway carful when my car starts to crunch.

[shepo]

Yeah that's what I do to avoid it crunching but I'd rather not do that forever

my 4th gear synchro's have been bad since the day i bought the car. as most are saying, its a very common problem in the GTR's. ive been "double clutching" the whole time. it helps it to the point where its virtually un-noticable. and if you get it right you can change almost as fast as you normally would. you just need to make sure that you match the revs.