Jump to content
SAU Community

Recommended Posts

Hello All,

I'm trying to narrow down what my clutch issue may be, so here's some information about the car and setup.

I have an Aus delivered R31 Ti, its converted to RB25det box and Has either a clutch to suit the rb30 box/fly or rb25det box/fly, I can't recall as it's been in the while but it Is an Exedy 5 puck clutch.
R31
NSK-6797HDB
Heavy Duty Button Clutch Kit
Or
R33
NSK-7056HDB
Heavy Duty Button Clutch Kit
It has had a lot of abuse which is what the car was built for.

I had the car at a drag meet and all of a sudden it ended up becoming hard to select gears, now I'm trying to find the issue.

The master cydiner and slave are both rb30. Box is 25det as mentioned.

Fluid was abit mucky so I replaced and bled it.

The pedal was abit sloppy, a small plastic bush/shim that conect the pedel to the adjustable master cydlinder rod was shot and gave the pedal abit of play as the small pin (6-8mm) that's connects the two goes though a 10mm hole with a shot bush to pick up the slack. I made a new bush and also adjusted the pedal so it had more throw on the master cylinder.
When I release the clutch pedal I am moving the pedal abit before the clutch engages which tells me I'm getting enough travel out of the pedal?

Next was the push rod between the slave and the fork, with some help i had the clutch pedal pushed in I manually moved the fork to see how much more travel it had after the slave was fully engaged and it could move around another 10mm so i made a new push rod about 7mm longer which made the car shift into gear easily but under boost the clutch slipped.

Any other suggestions? Obviously I don't want to pull the box, do I just need a push rod 3.5mm longer than standard? Is it the diaphragm/fingers on the pressure plate?

Probably not important but the car is running a RB30DET with 350rwkw.

Thanks
Adrian

20200121_191853.jpg

Link to comment
https://www.sau.com.au/forums/topic/479596-rb25det-clutch-issues/
Share on other sites

2 hours ago, GTSBoy said:

That would never be the case.

It is either hydraulic (ie, master or slave bypassing), or the clutch has a mechanical problem.

Is there any difference between 25 and 30 slave cylinders?

 

When i first did the conversion the orgnial/factory pushrod didn't suit so I made another one and that has worked for around 7 years. Untill my current issue.

 

I have no fluid leaking from slave or master.

 

As mentioned it still engages the clutch soild without slipping but not great when changing in any gears.

14 minutes ago, the-31 said:

Is there any difference between 25 and 30 slave cylinders?

I don't know. Well, actually, if the RB30 slave is for the NA box, then probably yes, because that box is related to the RB20 boxes and they are definitely different to RB25. The RB30 turbo box is basically the same box as the RB25, and so there is a better chance that the slaves would be same-ish.

15 minutes ago, the-31 said:

I have no fluid leaking from slave or master.

Bypassing is an interval event.

 

15 minutes ago, the-31 said:

 but not great when changing in any gears.

Which tells you that it is not disengaging sufficiently. Which is either lack of hydraulic effect, or something broken at the clutch itself.

 

The reason that it slipped under power when you lengthened the rod was that you were always applying load onto the clutch release, which is a no-no and wears shit out real fast.

4 hours ago, GTSBoy said:

Which tells you that it is not disengaging sufficiently. Which is either lack of hydraulic effect, or something broken at the clutch itself.

Once the hydrulics are at full stroke the fork doesn't move back in on it own as if there is fluid bypassing? 

4 hours ago, GTSBoy said:

The reason that it slipped under power when you lengthened the rod was that you were always applying load onto the clutch release, which is a no-no and wears shit out real fast.

I under stand the slipping. 

 

Just don't understand how it's such a fine line between crunching gears and having traction or shifting smoothing but slipping clutch, with the length of the push rod. 

It could be something in the clutch itself but I hope not.

 

By the sounds of what information you have given the pushrod shouldn't affect it and should never have been changed?

 

46 minutes ago, the-31 said:

Once the hydrulics are at full stroke the fork doesn't move back in on it own as if there is fluid bypassing?

No. Master and slave cylinders are pistons with seals. When the seals are f**ked, the hydraulic fluid is not all pushed along in front of the seal, it slips past the seal, reducing the hydraulic power.

42 minutes ago, the-31 said:

It could be something in the clutch itself but I hope not.

If it is not a hydraulic problem, then it is something mechanically f**ked in the clutch.

  • 2 weeks later...

Well it seems to be stuffed. Pressure plate fingers look to be good, still meat on the clutch but it seems to have worn the pressure plate and the flywheel.

 

Any recommendations for a new clutch? Something cheap, drivable and capable of 350rwkw. IM not looking to push more out of the engine.

 

Thanks

20200204_211856.jpg

20200204_211902.jpg

20200204_211829.jpg

20200204_211937.jpg

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

    • I've heard the Tomei USA head gaskets are decent if you want to o-ring the heads but otherwise not recommended.
    • The 296mm rotors are the R33 turbo brakes. The 310mm rotors are the R34 turbo brakes. The calipers are nearly the same, but not. They're the same caliper but the R34 caliper has longer legs so that it sits out far enough to go over the rotor. The pads are the same for both. When you say, "I bough tsome EBC"....did you just mean pads? Or rotors? 310mm rotors fit under 17" wheels. There may be some wheels without enough clearance though. I can't fit my fingers between the barrel of my wheel and the "corners" of my R34 calipers, but there is plenty of room behind the spokes. This is on Enkei RPF1. You can fit 324mm rotors inside a 17" wheel, but I'd be willing to bet that it would be close to impossible with the Nissan/Sumitomo caliper (using an adapter, of course), because the Sumitomo caliper is fatter than the Brembo caliper that is supposed to go on the 324mm rotors.
    • Hi. Can someone tell me what brakes(and mainly WHERE) can i buy brakes on R34 GTT? I bought some EBC which SHOULD go on my car(i have GT but it has GTT brakes) but it does not fit, Brakes are "too" small(296mm) Are 310mm be good or? I have 17 inch wheel so no "big boys" but for me driving i just need one that fits and i can get here in EU/Czech.
    • Since winter isn't that harsh anymore in Poland, i will definetely drive it 365 days a year 😉. But if the snow hits i will try it for sure and let U know. Only swap i am planning to do is of course R34 GTR front 😍.
    • Hey. Very valuable information about pitwork, I will pay attention when buying any consumable parts 🙏 As for the carpets - I got a handful of information from nengun, from which it appears that indeed the carpets for the driver's side are OEM. They are not able to show me any pictures due to the long chain of different sales entities but after I place the order, as soon as the goods arrive at the nengun warehouse from which they will send the shipment to me they can send me photos and if my purchase differs from OEM I can immediately return it / cancel the purchase. I think I will give it a try 😉. Of course i'll let you know what's what as soon as i get them P.s. I know the topic is not relevant to the thread, but both nengun and amayama have these SICK 😍 trunk room lamps available. Do you know anyone who ordered them? I need to have one in my car
×
×
  • Create New...