whats slipping and what to do?

[GTR 94]

well it all comes down to age, in the beggining its as solid as a rock but over time it becomes dust! so what to do???

well running absolute standard R32 GTR except for HKS EVC boost controler on .85 bar high boost (roughly 10 pound), driving along nice open road, flick to high boost still in 5th and ease to about half throttle moving along and hit 140 and the tacho flyies up to 7 grand "shit whats that REV REV" nothing take foot off throttle and everything back to normal.

Is it clutch, fly wheel? i find that if im in 3rd or 4th and punch it. it doesnt miss a beat just pulls like a rocket but 5th and under load no good.

So do i wait till its totally stuffed or will it begin causing problems else where.

i am triing to save to go to america in June but when i get back im gonna go all out and aim for at least 300+AWKW should i just forget it till then and upgrade clutch and flywheel after trip or does this need to be fixed NOW?

thanks kindly.

[Bazelinez]

Your clutch is knackered dude... WHen your in fifth the gear is too tall to mask the problem so it slips...

Get a decent heavy duty/single plate replacement if you don't wanna spend more then $1.5K

If you nurse it and it doesn't slip you should be okay, keep giving it shit and the flywheel will eventually get scored requiring machining to fix.

[terry.m]

Hmm...I disagree.

If she's pulling like a beast in all other gears I would not suspect the clutch. Test the clutch for slippage by:

- Be stationary in you car (ie. not moving)

- put the car in 5th gear and put the hand break on

- try to take off

If the engine stalls the clutch is fine...if the revs pick up and continue to do so, the clutch needs replacing.

I had a similar problem in my GTS-T but it happend during take off. I did a gearbox oil change and added Shell Synthetic oil with a Nulon gear box additive. Since that, when I tried to engage a quick start, the engine would rev off its nut but I wasn't going anywhere...WTF. As it turned out, it was my synchro's that were slipping. I immediately changed the oil to Castrol VMX80 (NO ADDITIVE) and after aboout 10mins of driving everything was fine. I have now changed the oil again to completely remove all the crap that I added originally.

In summary, it may be a cheaper option to spend $35 and change the oil before resorting to a new clutch...it cant hurt.

[Abo Bob]

That's interesting Terry. I didn't know that could happen.

And 0.85 bar is 12.5 psi.

[Hiroshima Screamer]

good way to see if its the clutch is to take it onto a highway take it up about third in a safe driving manner . The rev and speed should go up about the same pace if one the needles is beating the other its defiantly the clutch i have gone threw 2 clutches now , had to get myself a twin and i wont ever go back

[terry.m]

Yer...I couldn't believe it Abo Bob...I was so P'd. That Nulon rubbish should be banned from being sold.

[GTR 94]

guys thank you so much for the help ill get back on the results as soon as i try it.

[gtst25]

That is not how a gearbox works.

Have you ever pulled one apart?

Synchos don't slip when the box is in gear - the synchros job in each gear is to stop the spinning gears when you change gears allowing the gears to mesh in together without crunching. They are a brake for each gear and don't do anything once the gear is engaged.

This is why a gearbox is called a gearbox, not a synchro box! Gears transfer the power, not synchros.

Changing the gearbox oil won't make an ounce of difference to the slipping you describe.

So my answer to GTR94's problem is the clutch is slipping. The car will need at least a new clutch plate - but if going to the trouble of doing this I'd be putting a whole new clutch kit in, machining the flywheel etc.

I just had the same problem with my r33gtst - the exceddy clutch kit I got works nicely.

The reason it slips in 5th and not other gears is the driveline will be under the greatest load in 5th because of aerodynamic drag.

Hope this helps

Hmm...I disagree.  

If she's pulling like a beast in all other gears I would not suspect the clutch. Test the clutch for slippage by:  

- Be stationary in you car (ie. not moving)

- put the car in 5th gear and put the hand break on

- try to take off

If the engine stalls the clutch is fine...if the revs pick up and continue to do so, the clutch needs replacing.

I had a similar problem in my GTS-T but it happend during take off. I did a gearbox oil change and added Shell Synthetic oil with a Nulon gear box additive. Since that, when I tried to engage a quick start, the engine would rev off its nut but I wasn't going anywhere...WTF. As it turned out, it was my synchro's that were slipping. I immediately changed the oil to Castrol VMX80 (NO ADDITIVE) and after aboout 10mins of driving everything was fine. I have now changed the oil again to completely remove all the crap that I added originally.

In summary, it may be a cheaper option to spend $35 and change the oil before resorting to a new clutch...it cant hurt.