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dave_hl

Clutch confusion ...blown?

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hi all.

last Wednesday night my clutch i think slipped majorly doing a bit of a burn out seeing as the car was moving off very slowly after revving out first and then popping it in 2nd and not much smoke out the back. the clutch and gearbox felt a little bit funny on the remaining 300 meter drive home and then when i went out to drive to uni the next morning the clutch wouldn't disengage.

 

I thought, dam i've blown it, took my dads car to uni and then later that day went to start the car again and to try and confirm it was the clutch before i started trying to pull it to pieces. only this time the clutch disengaged fine and i could reverse the car up the driveway and went into all gears fine. i put some strain on the clutch accelerating fast up and down the driveway and dropping it straight out stalling the car but it still engaged and disengaged perfectly fine.

 

I don't trust it at all to just forget about it and keep using it as my daily driver, does anyone have any theories on what might have been or what might be wrong? Might sound stupid but whenever i accidentally grind the crap out a of a gear doing something stupid and the gearbox doesn't feel 100%, i'll come out the next day and the car seems to have healed itself, haha.

 

I should also add that the clutch pedal felt normal both times, possibly a little bit softer when it wasn't disengaging, though maybe i was imagining that.

 

cheers, dave.

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hay dave you may have done what i did and burned your pressure plate. my advice to you would be to change your clutch other than that adjust it and see how it goes. if you change it use a excedy hd clutch it will be about $200 and feels nearly the same as the regular one but man does it bite well.

 

 

cheers pauly

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well i drove it for about 15k's today and went fine, but i noticed when letting the clutch out from stand stills the car will shudder/vibrate a tiny bit. does this imply something is warped perhaps? I guess whatevers wrong i'll be replacing whats in there with a new clutch kit anyway. Just annoying coz it's booked in at the tuners for this friday...

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Just rang the tuners to cancel my friday booking and he reckons it was just stuck engaged from overheating and should be right. anyone reckon this sounds about right?

 

cheers.

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sounds like it overheated from the attempt of doing the burnoout. u pressure plate has been damaged and probably litle bit warped as u said through the vibrations.

 

it will still drive ok if u drive carefully but any more attempt of going hard will result in more slips and possibly cracking of the pressure plate. if that happens than you will have to change gears without clutch.

 

so is it going to be good as it was?  simple NO. but if u drive carefully u can pull few Km out of it still. but it will only get worse. new clutch and refaced flywheel should fix all the issues you currently have. go for daikin exedy heavy duty clutch.

 

 

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sweet, thanks for thanks for the reply's. Hopefully it will hold up alright on the dyno on friday. Do Bursons sell exedy clutches at reasonable prices? A mate was telling me he could get me a trade discount there.

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your best bet is autobarn or if you have a mate thats a mechanic like i do, should cost you about $130 for a std excedy clutch or $200 for a heavy duty it cost me $160 cause of my mate, like rbz 260 said just dont give it a boot full or it will slip again then it will just fall to peices and youll be stranded or driving very slowly down the highway like i was.

 

 

cheers pauly

 

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rang a couple of places and prices seem to vary by about 60 bucks between the 225mm and the 240mm... is there some way of checking which size i need?

1980 series 1 280zx i think the car may have been converted to manual many years ago so not sure exactly whats in there.

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Cheers ben,

been lookin at a few clutch kits on the net and half which say they are for an '80 280zx are 225mm and half are 240mm...

This is rather confusing.

is Ben correct; am i after a 240mm?

 

sankyou

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Well got myself an exedy sports tuff heavy duty clutch kit, cars putting out a bit under 120rwkw and im not always nice to it so thought i'd get something a bit beefier then what was in there. Pulled it all out today, the disc was so worn; down to metal on both sides, the rivots were nearly falling out and had the tops shaven off them and the springs were all lose. i'm surprised it still worked semi alright.

 

As i half expected the flywheel is a bit burnt and has a slightly uneven surface, does anyone know a decently priced machine shop? im in Mont Albert. I also just read evans post about his clutch troubles and people talked about getting the flywheel/clutch combo balanced when the flywheel gets machined. Is this just lathing the flywheel so its completely even, or is there something else that can need doing.

 

My last question is with a centering tool, ive read just using a socket extension woks fine, or is it advisable to get my hands on an actual proper centering tool.

 

And is it worth looking into a lightweight flywheel, i've read they'll help the engine to spin up faster but not give more HP, but if you go too light the car will stall easily. considering im an unemployed student i think i'll leave it how it is for now.

 

cheeeeers fellas.

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Well got myself an exedy sports tuff heavy duty clutch kit, cars putting out a bit under 120rwkw and im not always nice to it so thought i'd get something a bit beefier then what was in there. Pulled it all out today, the disc was so worn; down to metal on both sides, the rivots were nearly falling out and had the tops shaven off them and the springs were all lose. i'm surprised it still worked semi alright.

 

As i half expected the flywheel is a bit burnt and has a slightly uneven surface, does anyone know a decently priced machine shop? im in Mont Albert. I also just read evans post about his clutch troubles and people talked about getting the flywheel/clutch combo balanced when the flywheel gets machined. Is this just lathing the flywheel so its completely even, or is there something else that can need doing.

 

My last question is with a centering tool, ive read just using a socket extension woks fine, or is it advisable to get my hands on an actual proper centering tool.

 

And is it worth looking into a lightweight flywheel, i've read they'll help the engine to spin up faster but not give more HP, but if you go too light the car will stall easily. considering im an unemployed student i think i'll leave it how it is for now.

 

cheeeeers fellas.

 

You need to get the clutch / flywheel assembly balanced with your harmonic balancer. This prevents your crank bearings from going to crap.

 

Depends how bad your flywheel is, but getting it lightened does help it rev. I quite like it in my 240z, but if it was any lighter I could see how it would easily stall.

 

I guess it depends on your budget, and what you want to do with your money. As a Uni student I'd probably just fix it up and worry about lighter flywheels later, once you finish Uni. Save you money for pints of beer lol.

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You need to get the clutch / flywheel assembly balanced with your harmonic balancer. This prevents your crank bearings from going to crap.

 

harmonic balancer... sounds fancy? or is this the thing you stick in the middle of the clutch disc while you're bolting in the pressure plate to keep it all centered...?

 

and what sort of rough cost is a lighter flywheel?? im guessing a 2nd hand one on my budget. is it the sort of part you need esspecialy for the zed.. or can i steal a 240mm one off some car at the wreckers.

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harmonic balancer... sounds fancy? or is this the thing you stick in the middle of the clutch disc while you're bolting in the pressure plate to keep it all centered...?

 

and what sort of rough cost is a lighter flywheel?? im guessing a 2nd hand one on my budget. is it the sort of part you need esspecialy for the zed.. or can i steal a 240mm one off some car at the wreckers.

 

I got a lightened one for $50 but that was a "Costa Special" inside joke there.

 

The Harmonic Balancer is the "pulley" on the front of the engine. Where all the belts run from. You need to match your clutch flywheel assembly with the harmonic balancer.

 

You will probably want to replace the pilot bushing and the rear main seal while you do the clutch.

 

My rear main seal on my car went and caused oil to splatter onto the clutch causing it to slip. Its like $10 but worth doing while you have the G/box out.

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$50! tell costa to give me a special!

 

My haynes didn't say anything about matching my clutch/fly assembly with the harmonic balancer, or is it just making sure its all centered and even with the centering tool..?

 

I've gotta wait till at least monday to get my fly machined, so i might try going about replacing the pilot bushing and seal tomorrow. cheers for the tip.

 

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It is a good idea to at the very least get the clutch/flywheel balanced as a unit before you install it. When I did mine, I was told lucky I did it because the clutch and flywheel were way out of balance! Would have shortened the life of the crank if I left it alone.. Any good machine shop can lighten your flywheel for next to nothing. usually when they face it you can ask them to take some kg's off! (then balance it)

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this may be a dumb question but how on earth do you balance a clutch/fly assembly together before its in the car?? you wouldn't be able to bolt the flywheel onto the engine if the pressure plate and disc were already attached to it.

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this may be a dumb question but how on earth do you balance a clutch/fly assembly together before its in the car?? you wouldn't be able to bolt the flywheel onto the engine if the pressure plate and disc were already attached to it.

 

You remove the flywheel from the car, and give it to the balancers along with your clutch pressure plate and friction plate.  They will then bolt it together, and balance, then will usually mark both the pressure plate and flywheel (maybe with a dot from a centre punch).  You then make sure it is marked (or mark it yourself), unbolt it, put the flywheel back on the car, and then put the clutch plates on, making sure it goes onto the flywheel the same way it came off.  Due to the dowels on the flywheel, the pressure plate can only go on in one of three positions, one of which your two marks will line up, the other 2 it won't.

 

*EDIT*  500 posts?  I've been around here too long....

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just measured my flywheel and realized its a 225mm, they must have put that in there when it was converted to manual instead of the 240mm. I then weighed it and its spot on 16 pounds, they must have lightened it too!  Probably why the bloke i took it to said he couldn't take much/any more weight of it.

 

Have returned the 240mm clutch and should pick up the new 225 tomorrow.

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If one were to over torque a pressure plate bolt and it snapped, and one then proceeded to drill out the bolt but was too lazy to take the pressure plate and flywheel off to use a drill press and so as a result F*&^'d the hole, would they be the stupidest person alive to leave the pressure plate with just 5 out of the 6 bolts holding it and proceed to install the gearbox, or would everything work a-ok and though not advisable work fine.

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If one were to over torque a pressure plate bolt and it snapped, and one then proceeded to drill out the bolt but was too lazy to take the pressure plate and flywheel off to use a drill press and so as a result F*&^'d the hole, would they be the stupidest person alive to leave the pressure plate with just 5 out of the 6 bolts holding it and proceed to install the gearbox, or would everything work a-ok and though not advisable work fine.

 

RAHAHAHAHA ;D

 

That's sooooo funny !!! Yes there is a good chance the flywheel will come loose with just 5 out of 6 bolts. Especially

if the flywheel does not sit perfectly flush against the back on the crank after drilling it.

Snapping a pressure plate bolt is fairly hard !!! Were you using like a 8 meter breaker bar !?!?!?!!?

 

 

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nah nah i've got all the flywheel bolts in, thats on the crank fine. Just the pressure plate attaching to the flywheel, its sitting flush and i put a big arsed screw driver in there to see how easily its gonna lift up where the bolt snapped and its sitting pretty darn tight. I was using a slightly longer ratchet then normal, but its probably mostly due to my bulging muscles ya know ;D I was turning it pretty hard, but not ridiculously... i suppose the pressure plate bolts aren't super thick.

 

I should probably invest in a torque wrench, or convince my dad to anyway! in fact it wouldn't surprise me if there is one hiding in the tool shed somewhere.

 

so my original question; should i really fix this or will i be right and just proceed to install the gearbox..?

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nah nah i've got all the flywheel bolts in, thats on the crank fine. Just the pressure plate attaching to the flywheel, its sitting flush and i put a big arsed screw driver in there to see how easily its gonna lift up where the bolt snapped and its sitting pretty darn tight. I was using a slightly longer ratchet then normal, but its probably mostly due to my bulging muscles ya know ;D I was turning it pretty hard, but not ridiculously... i suppose the pressure plate bolts aren't super thick.

 

I should probably invest in a torque wrench, or convince my dad to anyway! in fact it wouldn't surprise me if there is one hiding in the tool shed somewhere.

 

so my original question; should i really fix this or will i be right and just proceed to install the gearbox..?

 

 

Ohhh its just the pressure plate bolt......Hahahaha I was thinking the flywheel bolt (i.e the 6 big ones that bolt to the crank)

 

Na the presure plate bolt wont matter too much at all. Tho if it was balanced using them it will be very very slightly unbalanced now. Other then that the one bolt shouldn't matter. :)

 

 

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