Jump to content
SAU Community

Recommended Posts

Bump.

Mates having the exact same problem with his pull clutch. Looking for internet help before I have to pull the box out myself :P 

It will grind all gears, but will eventually go into gear.
Engagement is all the way to the floor.
Brand new single plate clutch with flywheel.
Master and slave were never separated.
Made a 4mm spacer for the slave to get full travel and it still won't fully disengage.

This seems to be a pretty common problem, with no resolve.

So I went from an RB25DET Neo bottom end to a RB30E bottom end. Gearbox/clutch/slave/master were all the same components.

Turns out that the crank in RB30's must be lost than RB25 as what was happening was the sleeve over the input shaft (the thing the throw out bearing sits on) was pushing on the centre of the clutch disk and pushing it into the Flywheel, providing drive even when the clutch was disengage.

So the clutch fork was moving fine, the pressure plate was being released no problems, but because the clutch disk was bent pressed against the Flywheel it was like it wasn't working.

So I got a small Dremel and cut about 5mm off the end of that shaft, put the box in and never had any more issues.

Thanks for the reply. Interesting and funny it was just enough not to work, but bolt on fine.

I think there may be a problem with the throwout bearing on this one. As there is a clip collar (circlip) that the fork bearing slips into and it is meant to hold them together? I haven't seen a gtr one before.

 

My theory is, if the circlip is damaged the fork bearing will grab a little and then pull through.

  • 1 month later...
On 27/08/2017 at 9:13 AM, iruvyouskyrine said:

So I went from an RB25DET Neo bottom end to a RB30E bottom end. Gearbox/clutch/slave/master were all the same components.

Turns out that the crank in RB30's must be lost than RB25 as what was happening was the sleeve over the input shaft (the thing the throw out bearing sits on) was pushing on the centre of the clutch disk and pushing it into the Flywheel, providing drive even when the clutch was disengage.

So the clutch fork was moving fine, the pressure plate was being released no problems, but because the clutch disk was bent pressed against the Flywheel it was like it wasn't working.

So I got a small Dremel and cut about 5mm off the end of that shaft, put the box in and never had any more issues.
 

Sorry to re bump

 V

but i think im having the exact same problem. Did a crankshaft swap in my motor. Bolted it all in and together but cant select gears when its running. 

Had the box back out, rechecked clutch, fork, bearing etc and all were good. Put back in and no good.

When you say 'cut 5mm off the end of that shaft' what shaft are you referring to? The crankshaft? Input shaft?

If you could describe it a bit more that would be great. 

You need to measure from the block to the throw out bearing face , and on the gearbox side from the belhousimg block mating surface to the throw out bearing and figure out what is going on.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...