Rb25Det Clutch Problem

[Bruno P]

Having issues with new clutch, about 500km ago I had a new Exedy Extra Extra Heavy Duty Button for an RB25det, Manufacture Part No: Exedy NSK-7056HHHDB installed, together with an exedy lightened flywheel and a Nismo clutch pivot.

Over the past week the car has these symptons,

Hard to get into 1st and reverse gear when cold, and just as bad when at running temp. With the clutch fully pressed to the floor and the car in 1st gear the cars still moves forward,

Gears grinding, impossible to drive,

Had enought of it and took it to the mechanics.

I sat in car on the hoist as he bleed the master and slave just to make sure there is no air in the system, or a leak. Still no improvement at all.

Mechanic is assuming its a problem with clutch fork, he thinks it may be bent, he wants to purchase a clutch fork before he pulls the gear box out.

Does anyone out there know or have had any similar problems, I'm a bit unsure about buying a new clutch fork before the box is removed just incase its not the problem.

and even If I replace it who's to say that the new clutch fork wont do the same, flex, break, or is there an aftermarket forged one I can buy.

Any suggestions?

Cheers

Edited June 18, 2011 by Bruno P

[GTSBoy]

It's either the clutch fork bent/split/otherwise f**ked, or the ball could be damaged (that happens a lot) or it could be that your clutch master is shagged, internally bypassing, and so only giving you half a pedal. Oh, and the pedal brackets like to split open as well, causing the same sort of crap.

If it were me, with a stupidly stiff clutch just put in, I would get a Nismo pedal bracket (or weld some extra bracing across the top of the original one) and get a new strong-as-possible clutchfork. Just 'coz. You're going to need to beef those up anyway or they'll just shit themselves at some stage. And budget for a master cylinder as well.

[defari]

bruno: you have the same problem i have - i havent been bothered to fix it yet but its either the clutch fork / master cyl or the pedal bracket is broken.. basically what gtsboy said...

i

[SargeRX8]

Your clutch is not being fully disengaged. Symptoms covered above. My car did the same, the spring in the master was broken into 3 pieces. Occasionally it would drive fine then at time it would just not get in or out of gears. I'd do the cheapest and easiest options first. Box out is a pain in the arse. These exedy hhhd clutches like breaking things. I went with something custom and the pedal feel is identical to stock but with massive clamp load and 5 puk clutch.

[Luke Vincent]

I had the same problem, replaced the master/slave and no change, nothing broken...

so one weekend got it up on ramps and removed the box to find out 6 of the 9 bolts holding the pressure plate on where pretty much coming out..

so the plate was on the piss and not being able t o dissengage the clutch...

you can tell if the fork/ball is broken/bent anyways though the inspection hole... generally..

hope this helps narrow it down.

[Bruno P]

eventually sent the clutch back to exedy and the clutch is deemed to be faulty as it wont release, cant believe it. they refunding money though.

BP

bruno: you have the same problem i have - i havent been bothered to fix it yet but its either the clutch fork / master cyl or the pedal bracket is broken.. basically what gtsboy said...

i

[SKY5HW]

Hi Bruno, I’m thinking of buying the same clutch for my r33 gtst Rb25det is this a good choice or not?

[GTSBoy]

You found a 6 year old thread but didn't find any of the millions of recent threads where the best answer is the Nismo twin?

[SKY5HW]

You found a 6 year old thread but didn't find any of the millions of recent threads where the best answer is the Nismo twin?

Is this a cushion button type?

[GTSBoy]

No.  Button clutches are not friendly.  The Nismo twin is a spring centre full face clutch.

Sprung centre = cushion.

Button = harsh

Full face = nicer to use

Twin = plenty of grip

[Robzilla32]

I have just had a Nismo Super Coppermix twin plate C-Spec installed in my GT-R and it is lighter than what I had in my 1987 MR2

[Dose Pipe Sutututu]

if you want a cheaper alternative to the Nismo twin, get a NPC Organic clutch. They utilise a 10" (a brand new modified Exedy clutch to their specs). Sprung centre, organic material, 1.7 ton clamping force.

Pedal  effort is same

[SKY5HW]

What’s the price on one of these?

[iruvyouskyrine]

700 push 800 pull