Push vs Pull Clutch

[elohim_imanu]

Unbelievably, I can not seem to find much about this subject on SAU. Maybe my search button is broke. I have have done a fair bit of Googling, but get mixed messages. You would think that since most GTRs have them and Nissan moved to them with the R34GTT, that it would be superior, but I see a lot of people converting, I can only presume because the market seems to be more varied. 

I am getting my hands on a new R34 big box which comes with a pull clutch setup. I am interested in peoples opinions of the pull system and if I should convert it to a push ($300).

The application is street driven R33 ~350HP, which I don't intend to drift or do burn outs.

Seems that the options for pull clutches are limited and they generally are more expensive. Is that just because they are more beefy? Considering an Organic Nismo Sport pull Clutch which will cost me about $800.

Thanks for sharing your thoughts and experience.

[r32-25t]

One isn’t really better then the other, the reason for converting is because most performance clutches are only made in push type and it easier for companies to make a conversion kit rather then making a different clutch 

[WR33KD]

Less moving parts and the pin won’t pop out when your putting the box back in. 

[SteveL]

Push type clutch has been around since forever.   Simple and relatively cheap to produce.    Pull type not so much in terms of design and application, but the pull type has advantages in terms of operating mechanism leverage so can give comparatively lighter pedal loads at increased plate pressure.

The weak points of the Nissan push type clutch mechanism (used in early GTR's, etc) are the clutch throw-out fork and pivot ball.       The design hasn't changed much since at least the 240z and is OK for stock or mildly up-rated applications, but increasing pressure plate ratings to competition levels can and has lead to failure of the clutch fork (fatigue cracking) and/or the pivot ball.     The BRE 240Z's were probably some of the first to identify the problem in competition in the US.

Most people will probably never have a problem.   It really only appears at high pressure plate levels.     I suffered a broken clutch fork in the Z at PI, and later a stripped friction plate on a supposed 'performance' clutch at the same venue....but that's another story.

NISMO make an uprated pivot ball for many Nissan's that use the push type clutch.   Not sure about the fork, but I'm sure that there's something 'billet' out there (and the crowd goes wild over the word 'billet'.....).

[elohim_imanu]

9 minutes ago, SteveL said:

Push type clutch has been around since forever.   Simple and relatively cheap to produce.    Pull type not so much in terms of design and application, but the pull type has advantages in terms of operating mechanism leverage so can give comparatively lighter pedal loads at increased plate pressure.

The weak points of the Nissan push type clutch mechanism (used in early GTR's, etc) are the clutch throw-out fork and pivot ball.       The design hasn't changed much since at least the 240z and is OK for stock or mildly up-rated applications, but increasing pressure plate ratings to competition levels can and has lead to failure of the clutch fork (fatigue cracking) and/or the pivot ball.     The BRE 240Z's were probably some of the first to identify the problem in competition in the US.

Most people will probably never have a problem.   It really only appears at high pressure plate levels.     I suffered a broken clutch fork in the Z at PI, and later a stripped friction plate on a supposed 'performance' clutch at the same venue....but that's another story.

NISMO make an uprated pivot ball for many Nissan's that use the push type clutch.   Not sure about the fork, but I'm sure that there's something 'billet' out there (and the crowd goes wild over the word 'billet'.....).

Great answer, never had that problem on my 260Z though. Must have been lucky. I had wondered why Nismo made that pivot ball. I think I am going to just get the Nismo pull clutch and keep the box standard. 

Anybody know if there is a difference between the R34 and R33 master cylinder. Do I need a R34 type as the slave will be a pull type. Will a R34 fit my R33 or will the stock R33 work anyway? I guess the R33 GTR is pull, but doesn't have some sort of booster?

[SteveL]

According to the parts lists I just looked at they all use the same clutch master (R32, R33, R34 GTR's) regardless of push or pull clutch, and the R33 does have booster.    That makes sense because the clutch master doesn't know or care about push or pull and any differences in travel, etc can be accounted for at the throw-out mechanism.    PN is C0610-05U00, superceded by 31610-05U01

[elohim_imanu]

34 minutes ago, SteveL said:

According to the parts lists I just looked at they all use the same clutch master (R32, R33, R34 GTR's) regardless of push or pull clutch, and the R33 does have booster.    That makes sense because the clutch master doesn't know or care about push or pull and any differences in travel, etc can be accounted for at the throw-out mechanism.    PN is C0610-05U00, superceded by 31610-05U01

Thanks. I was not sure if there was some sort of fluid transfer difference.