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Clutch Engagement Issue


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#1 GreenMini17

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Posted 11 May 2014 - 06:46 PM

Quick, simple answer needed please. Is it normal for engine revs to dip by between 300-500rpm when you put your foot on the clutch pedal? Bearing in mind i have a grey-dot diapragm with AP racing clutch, pre-verto set up and 0.1mm of crankshaft end float? Thanks in advance.

#2 Guess-Works.com

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Posted 11 May 2014 - 06:51 PM

oh dear... that sounds like your crank thrusts are worn...

 

Have you check the end float with a DTI ?

 

The grey diaphragm will mean you need a fair amount of force to depress the clutch, may be worth checking the clutch release bearing.. but these usually make a loud squeal when they are falling apart.



#3 GreenMini17

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Posted 11 May 2014 - 06:56 PM

Clutch release bearing is brand new. As for the end float, i checked it with a feeler gauge between the thrusts and the crank web. The thrusts are new also (when i say new they have done about 30mins of engine running at idle).

#4 brad-the-bear

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Posted 11 May 2014 - 07:39 PM

you got a lightened flywheel?



#5 GreenMini17

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Posted 11 May 2014 - 09:05 PM

you got a lightened flywheel?


Yes I do.

#6 Guess-Works.com

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Posted 11 May 2014 - 09:15 PM

Clutch release bearing is brand new. As for the end float, i checked it with a feeler gauge between the thrusts and the crank web. The thrusts are new also (when i say new they have done about 30mins of engine running at idle).

 

Silly question, but did you put the thrusts in the right way round ?



#7 GreenMini17

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Posted 11 May 2014 - 09:59 PM

I didnt put the thrusts in myself but when i checked them, yes, they appeared to be in correctly (as the haynes manual shows them) this was the only reference i had!

#8 brad-the-bear

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Posted 12 May 2014 - 06:08 AM

can you get any gears?



#9 Guess-Works.com

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Posted 12 May 2014 - 06:41 AM

I didnt put the thrusts in myself but when i checked them, yes, they appeared to be in correctly (as the haynes manual shows them) this was the only reference i had!

 

On that note, I'd be pulling the engine out and checking before you scrap the crank and the block.



#10 The Principal

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Posted 12 May 2014 - 07:10 AM

agree with the previous comments plus I would be checking the clutch throw, check the adjustment of the clutch arm. You can wind the stop nuts in towards the clutch cover a touch its trade off between pushing the crank against the thrust washers and getting the clutch to disengage. The grey diaphram wont help because of the force needed to push it so the stop nuts will prevent the clutch pressure forcing the crank against the thrust washers



#11 GreenMini17

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Posted 12 May 2014 - 07:11 AM

can you get any gears?


Yes i can. Clutch engages and disengages fine.

#12 GreenMini17

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Posted 12 May 2014 - 07:14 AM

agree with the previous comments plus I would be checking the clutch throw, check the adjustment of the clutch arm. You can wind the stop nuts in towards the clutch cover a touch its trade off between pushing the crank against the thrust washers and getting the clutch to disengage. The grey diaphram wont help because of the force needed to push it so the stop nuts will prevent the clutch pressure forcing the crank against the thrust washers


If i adjust the clutch up correctly (from the info provided on here) then i cannot get it into gear. You cant even force it into gear. If i wind the over throw nuts right out (towards the end of the thread) the clutch works fine, just that the engine revs dip a bit.

#13 The Principal

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Posted 12 May 2014 - 07:31 AM

If your sure the bottom end has been built correctly I'd be trying to find the sweet spot in the clutch adjustment somewhere between - 'cant get it in gear' and 'stalling the crank'. The alternative could be to strip in down as mentioned above.

 

The grey diaphram is a hefty piece of kit do you need that? the orange diaphram works fine on cars just over 100hp



#14 GreenMini17

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Posted 12 May 2014 - 04:25 PM

If your sure the bottom end has been built correctly I'd be trying to find the sweet spot in the clutch adjustment somewhere between - 'cant get it in gear' and 'stalling the crank'. The alternative could be to strip in down as mentioned above.
 
The grey diaphram is a hefty piece of kit do you need that? the orange diaphram works fine on cars just over 100hp


Im not an engine builder but from what knowledge i do have, the bottom end looked fine. I think it is down to clutch adjustment but i do tend to worry an awful lot!

As for needing a grey diaphragm, yes it is required. Its on a turbo set up running about 150bhp.

#15 Dusky

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Posted 12 May 2014 - 04:35 PM

Any electronics switched with the clutch? 






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