Jump to content
HybridZ

clutch problems


evildky

Recommended Posts

OK so I replaced my clutch with the CC stage4 and replaced my flywheel with the fidanza aluminum flywheel, and swapped my KA 5 speed in favor of a T-5 and had a custom shaft made,

 

now I can't get the clutch to disengage!

I swapped in the T-5 with the fork and collar that came with it but I just don't seem to be able to get the travel I need! the fork is about 3/4" from reaching the back of it's opening and the piston inside the slave is about 1/2" short of reaching the end of it's stroke with the pedal to the floor!

 

I adjusted the pushrod all the way out and even raised the pedal stop so I could get the rod out a bit more, but for some stupid reason it doesn't seem to make any difference in the travel of the slave, I knw I have to be missing something stupid but everything should be ok, the clutch master and slave are maybe 2 years ols (this is a garage kept race only car so were talking a few thousand miles MAX!) the trans was installed with the colar and fork that came with it but I can not confirm they came from the same donor I got them third party, I did replace the throwout bearing with the one that came with the cc kit but other than that I kept it as a whole

 

I am pulling my hair out and need to be ready to dyno saturday and race sunday, any help before I dig out my eyeballs with a spoon?

Link to comment
Share on other sites

I had the same problem with a 240Z that a late model 280Z 5-speed had been installed into. Replacing the master cylinder fixed it. Seems that the master for the 240Z does not have the internal volume that the 280Z (and later) one does. In my case, the master that worked was differentiated visually by having the hydraulic port about 1" aft of the 240Z part that didn't work. Strange because they have the same bore diameter.

 

Another issue - the slave for the T5 is a different part than the one for the Nissan trannys. I think you have to have that slave for the T5.

Link to comment
Share on other sites

so I thought I had it figured out, it occoured to me that at some point I recall changing the master's pushrod for a shorter one, I dog through my shelves and found one pushrod that was about 1/4 longer, I installed this and can get just barely enough movement to get it to disengage but the piston in the slave is still a good 3/8" from reaching it's furthest point and the pushrod is the longer one and it's adjusted all the way out and I even removed the pad from the pedal stop, I considered turning the pivot out and putting a washer or 2 under it to raise the fulcrum but the problem is that I do not have enough stroke, at rest the TO bearing is resting right up against the tines of the PP, I simply need a larger diameter master or a smaller diameter slave so I can get enough travel with the alotted pedal movement, which makes me ask did the early cars use a different pedal box? perhaps the pedal fulcrum is higher in the later chassis as no-one else seems to haave this problem, any body got a brilliant solution?

Link to comment
Share on other sites

the clutch fork looks identical to the others I have laying around, if anything it looks short but that would decrease the bearing travel and thats the opposite of what I ned so I guess the fork is ok, as for the bearing collar if ti were different it wouldn't help as I am just not getting ewnough travel at the bearing, at rest it touches the tines of the pp and at full extension is is barely disengaging, and the slave that came with the trans was marked 3/4 I believe and was rusted badly, I am using the same slave I ran with my last 2 transmissions which were stock 4 speed and ka 5 speed, the bore looks the same as the one that came off the T-5 but I didn't verify although napa did show the same part number for an 85 ZXT as a 78 280Z

Link to comment
Share on other sites

did you compare the pressure plate to the old one to make sure its not a different depth? and did you bleed the lines?

The pedal returns fine i take it..

 

maybe just maybe the slave is bad, wish i could help

Link to comment
Share on other sites

havn't compared mounted depth of the CC to the CM butthye should be within the same range, I never cracked the lines in the swap but after encountering issues I flushed and bled the system with no change, pedal returns just fine although I did notice in comparison the early pedal box lacks the extra support that later box has

Link to comment
Share on other sites

  • 3 weeks later...

just an update, I finally found time to fight it some more, I replaced the master and slave with new units, no change, I drilled a hole in the clutch fork and installed an early style smaller diameter slave, no change, I pulled the tranny, everything looked ok, the TO collar was the mid sized one, I replaced it with the long one and reinstalled the trans, no change!

 

I guess tomorrow I'll pull the trans againa nd try installing an off the shelf naoa or aurozone clutch and see if I can get them to engage and disengage

Link to comment
Share on other sites

I have issues with my clutch as well that I am chasing. I have the T5 with the collar and fork that came with the trans and it would not disengage (Centerforce stage II clutch for '83 turbo car) I put an 11/16 bore slave from an '89 240sx. 72 and earlier cars came with the smaller bore master, but my auto parts store does not stock it. But the 240sx slave is identical in external size to the 73 and up slave and uses the same style pushrod. This at least allows me to drive the car, but it drags where I cannot shift at higher rpms with any speed.

 

I bought brand new ZX release parts from Motorsport which is my next step. They show a unique part # for the fork. I have a replacement master, but hate to change that again. When my vacuum booster went out the only replacements were for '73 and up. This requires drilling the firewall for the larger bolt patter on the larger booster. Now I have to loosen the booster bolts and pull it away from the firewall in order to remove the clutch master. PITA. My car was broken for so long, I haven't worked up the courage to tear it back down again, but will do soon.

Link to comment
Share on other sites

well, I bought an autozone clutch but didn't install it, I pulled the flywheel and all and put it on a press and got it to disengage with about 1/4" stroke of the to bearing, I measured from the mounting surface on the back of the flywheel to the tines of pressure plate and compated it to a stock unit and it is about 3/16" thicker than the stock set up

 

I have used the medium and long style throw out collars, I have now added a washer under the pivot ball and was going to try the small throwout collar but when taking my clutch apart one of the bolts snapped off in the flywheel so I'll be going back to the machine shop before I try sticking it in again

 

as for the clutch forks I compared the one that came with the T-5 (which I have since drilled a hole in for use with the early 11/16" slave with adjustabel pushrod to no avail) and they all look identical except the early (70-71.5) which has the hole for using the adjustable pushrod and the tab for the external return spring

 

as for the slave cylinders, the 82-83 T-5 slave is a slightly different unit, it's the same 3/4 bore but it had a notch on the back of it that would not allow it to bolt flatly to the 4 speed bellhousing (and I assume the early 5 speeds and N/A 5 speeds as well) you can use the standard 280 slave with the T-5 but the T-5 slave von't sit on the standard 280 trans

Link to comment
Share on other sites

so I have now tried every t/o collar and finally installed the autozone clutch , maxed out the pedal with the new master and it worked! took it all back apart and put the CC clutch back in and it will not disengage! is there something wrong with the the cc unit?

 

with the autozone cluth it disengaged further down the pedal than it should but is is getting full disengage before bottoming out anf the pedal effort falls off a bit towards the bottom, with the CC the pedal effort builds for the firts half o the pedal then remains constant? I actuated the assembled CC on a press so I know it can work!

 

I am really tired of pissig with this thing, I am about the put the autozone clutch back in and scrap the Competition Clutches unit, maybe I should try ACT

Link to comment
Share on other sites

so I called Competition clutches and they said it sounds as if I have a bad pressure plate! they were very nice and polite and didn't infer that I made some boneheaded mistake, they said they would overnite me a new one and to send the offending pp back, excellent customer service! I only wish I had called sooner! with my car on jackstands and running it now takes me only 23 minutes to pull the tranny, would be a lot faster but the forward mounted swap bar really slows down the drive shaft removal, I must have had the trans in and out 20 times in the past month, I am gonna cry is this isn't it

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...