Clutch pedal adjustment

Discussion in 'Z32 Technical' started by Cliff, Apr 13, 2019 at 10:17 PM.

  1. Cliff

    Cliff Member

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    I've installed a new clutch from Concept Z (Mcleod Racing Stage 4) and I am trying to adjust my clutch pedal before driving.

    I've read some good detailed posts about what needs to be done
    mostly this one: http://specialtyz.com/blog/?page_id=178
    but I cant quite comprehend what I'm doing here. Specifically, I'm not sure if I need the bolt part to be inside the bracket of pushed outside.

    Sorry this is hard for me to explain.

    I know the idea here is to have the clutch pedal engage where it is just touching the two clutch switches (circled in green) but even when I back the bolt part all the way out (circled in red) it still feels like I get pressure on the pedal while still touching the switches.

    I dont want to damage my new clutch / flywheel but I cant see any way to get more play in the pedal. Am I over thinking this or do I need to make more adjustments somewhere?

    Screenshot_20190413-081420_Gallery.jpg

    Screenshot_20190413-081437_Gallery.jpg
     
  2. rob260

    rob260 Moderator Staff Member

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    Hi mate check out the FSM slide CL-7 on it shows adjustment procedure and specs for free play etc. Very helpful.

    http://www.300zx-twinturbo.com/cgi-bin/manual.cgi

    With an H/D button type clutch you want to adjust it so that the clutch engages quite low.
     
  3. IB

    IB ?????

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    Don't worry about the switches. You want to adjust the clutch pedal so that the engagement point is reasonable close to the floor and the clutch is fully disengaged when the pedal is on the floor.
     
  4. Cliff

    Cliff Member

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    Thanks rob. I've adjusted the pedal to what I think is supposed to be correct. It engages when the pedal is pressed about 60 - 70% to the floor. However, now I think my new throw out bearing is making a whining sound. Hopefully it's breaking in and not just breaking lol.

    The whining sound is only present with the car in neutral and clutch pedal released. I did read more than one post on 300ZXs specifically having the same issue and never caused a problem. I'll give it a week or so to see if it gets worse or stays the same.

    Thanks for the fsm reference. Dont know why I didn't look there first o_O
     
  5. Cliff

    Cliff Member

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    Also, for the adjustment it was easier for me to feel when the clutch found pressure with my foot rather than my hands. Maybe that will help anyone that finds this post in the future :)
     
  6. Martin Williams

    Martin Williams Active Member

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    New bearings don't break in, they are as good as they are ever going to be when initially fitted. If as you say you are getting a whining sound when car is in neutral and clutch is fully released it indicates one of the following.

    1. Your throw out bearing is stuffed and still in contact with clutch.
    2. Your throw out bearing is not fitted squarely.
    3. Your gearbox input shaft bearing is worn, (less support from gear train when in neutral)
    4. Worn/ Damaged or no spigot bearing in flywheel. (you did fit a new one?)
    5. A combination of all of the above
     
  7. Cliff

    Cliff Member

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    Thanks for sharing your thoughts on this Martin.

    My whining noise sounds exactly like this one from a 350Z:



    I know the internet is full of conflicting info but the 350Z forum (where I found this video) seem to be in agreement that this particular noise is normal:

    https://my350z.com/forum/maintenance-and-repair/588349-input-shaft-bearing-noise-is-it-normal.html

    I'm not responding to challenge your thoughts on what may be the cause of my issue, I just thought it would be a better assessment now that I have a similar case to show everyone.

    FWIW I did notice some whining under the same conditions before the clutch change but it was a more subtle noise before. I did use a full clutch kit from COZ which included clutch, pressure plate, throw out bearing, and pilot bushing. Also, I have a Z1 lightweight flywheel that I had resurfaced at my local machine shop.

    Mine is an upgraded clutch which is supposed to be good for about 500 ft/lbs of torque. I've never had an upgraded clutch before so I was wondering if maybe that had something to do with it.

    I'm going to try and put some miles on the car this week and see what effect that has. If the noise seems to be worse I will take the engine and tranny out for a closer inspection. Note, I dont have a tranny lift or tranny jack so pulling it out with the engine is my only option.

    Thanks for the thoughts and suggestions so far! I mostly want to make sure I dont end up with this again:

    Screenshot_20190328-155524_Gallery.jpg

    Screenshot_20190328-155544_Gallery.jpg
     
  8. Martin Williams

    Martin Williams Active Member

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    Let me just say a whining noise in neutral on any car is not normal. Throw out bearing does not stay in contact with the finger springs of clutch when clutch pedal is released if adjusted properly. If the noise doesn't annoy you, it will probably last a long time. My experience comes from having a gearbox input bearing fail completely coming downhill into Hungry corner at Lakeside raceway. It locked up the rear of the car at speed and shattered every cog and the gearbox casing. Anyway good luck with it.
     
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  9. Cliff

    Cliff Member

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    Thanks again Martin. Unfortunately the original cause for me to pull the engine (leaky valve stem seals) still persists. The new clutch was a bonus, while you're in there mod.

    I've no clue how, but the exact same symptoms (smoking under vacuum, smoking at startup, oil leaking on top of cylinder head...) in the first 13 miles of driving since replacing all the valve stem seals with vitton seals. I'm confused and tired so im just going to back away and let the Z sit and think about what's she's done for a while. Whenever I pull the engine again I will give the tranny a close inspection.

    Thanks everyone
     
  10. Polishzx

    Polishzx New Member

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    Hello,

    If the car feels OK to drive in terms of clutch/trans, you may not have to go back in. However, I just wanted to mention that in your first pic it looks like the lock nut on the rod is not fully locked. You definitely want that free play in the clutch pedal that the SZ blog mentions. Did you do any adjustment on the rod at all with pliers? It took me some time to figure that one out when I was installing a new NA clutch master cylinder. Then, be sure to fully lock the rod position with that nut up against the welded bracket.

    Sorry to hear about your engine pull results. Maybe it was just residual oil that still needs to burn off? Best of luck with figuring it out.
     
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  11. Cliff

    Cliff Member

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    Thanks for your reply Polishzx. Yeah the lock nut was loose just because I was in the middle of adjusting it when I took the picture (good eyes). It's such a pain of a job I just wanted some second opinions before tightening everything back up. Everything is sured up now though; well everything clutch alignment related that is.
     
  12. Shane001

    Shane001 Well-Known Member

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    I have exactly the same noise in the race car as in the video above. Mines always been like this as far as I can remember.

    I read somewhere (or did I assume?) that this was due to running a cushion button clutch plate. Can anyone comment on if this is correct?
     

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