clutch slipping - strange

[dhen]

The clutch was slipping today on when I went for a drive. Can anyone think of any reason it would do this besides a bad clutch? I think I may have had the clutch pedal adjusted wrong - needed more slack. It engaged right away when I pushed it down a little. I adjusted it once and it got better and then it came back. I've adjusted it again, but this is weird.

Never had a problem in first or second gear. Always 3rd-5th and when I shift quickly.

The reason I ask, is it would only do this after I drove a while and was speed shifting after the third shift. The first two were fine. Kind of like the clutch wasn't returning. Do the slave cylinders go bad on these things? Is there any way to know if the clutch plate is too loose without pulling the whole thing?

I'm running 12PSI of boost and have a SPEC stage 2 clutch. Have a Wilwood 3/4 cylinder for the clutch. Only 6500 miles. I can't rule out that it got dirty, but I don't think so.

I just want to check everything before I pull the engine.

[dhen]

I should probably add that this happened after I put in a limited slip differential, so maybe the clutch has been marginal all these years and this pushed it over the edge...

[float_6969]

When a clutch first starts to let go, it will do it in the upper gears first. The torque multipliers are the lowest there (5th is a reverse torque multiplier, so it puts the greatest stress on the clutch).

That being said, it could be a sticky clutch master/slave, or a deteriorated clutch flex line. The clutch master/slave/flex line are WAY cheaper and easier to deal with than the clutch, so I would start there.

[dhen]

Thanks. I know that any S13 slave will work, and RockAuto has them for $13

If I do have to order a new clutch, any recommendations for a brand?

[float_6969]

I like SPEC. The ONLY reason I went with ACT this time around was because I needed a new flywheel too and the cost of a CA flywheel and clutch for the power level I needed was $400 more than getting an SR clutch/flywheel combo.

[dhen]

I have a SPEC 2. It is pretty on/off. Kind of sucks in traffic, but a slipping clutch sucks worse.

Would a stock one be OK with 12 PSI of boost? My car is lighter, but I like to beat on it sometimes.

This one is supposed to be the same as stock:

http://www.ebay.com/itm/161045809304?it ... 23&vxp=mtr

I've heard mixed things about this clutch:

http://www.ebay.com/itm/XTD-STAGE-3-RAC ... e2&vxp=mtr

Thanks

[boost_boy]

I'd say go with the XTD unit. Don't be surprised that you will have to make some small mods to make it fit correctly.

[dhen]

Aren't small mods a little messed up on something spinning at 8,000 RPM? What do you mean?

Thanks

[mdb4879]

I might try adjusting the pedal even further down. Idk if this is how it works, but it's my speculation. If the pedal is up too high then as everything gets warmed up there's some expansion and the pedal gets pressed against the top of it's travel and let's the clutch slip. I've had a couple of my cars do that before when adjusting the pedal.

Doesn't it totally slip, or just doesn't grab as hard as it use to? If it just doesn't have that "kick" it use to have then I would think nothing is wrong. Just the pads aren't as fresh as they use to be and don't clamp as hard. But you'd know a lot better than me how strange your car is feeling.

Personally I'd go with a Spec stage 3 in your situation I've had several strong clutches and they feel normal to me now. They're easy for me to control and very responsive, lol. I can't stand really light clutches now. Anyways, idk if a stock clutch would hold that much power. A brand new KA clutch could probably hold it. Only $80, too.

I had one off a motor, but didn't like how the bolt holes lined up and feared balancing issues so I didn't use it. Then again, I finally got to try my 12lbs flywheel and it didn't have dowel pins. So I got the proper pins for it, but they didn't quite line up with the holes on the pressure plate after I enlarged them, so I slotted them to make it fit. Point being, I thought I'd have balancing issues with the minimal modification required to run a KA clutch, but did much more modification to the CA clutch I used to run a certain flywheel and all seemed fine.

I have an ACT stage 3 clutch with a sprung hub and I think it's an absolute joy to drive. But it's hard to gauge how you'll like something based on someone's opinion online. A stock KA clutch I think would hold the power, but it wouldn't bite like most aftermarket clutches would (something you'll want if you're power shifting or speed shifting).

[dhen]

Well, I adjusted the pedal to engage closer to the floor, took the car for an easy 1-hour drive to make sure it was warm, and then beat the hell out of it a couple of times. The problem seems to be gone - for now. I'll keep an eye on it.

That's the thing about a custom swap, I don't think you could do this with an OEM car. Oh well.

I should probably pull the engine to look at it anyways, I just don't want to. Would a loose pressure plate make noise?

But it's hard to gauge how you'll like something based on someone's opinion online.

Fair enough, but online opinions are all I have right now. This car is a lot of fun to drive and I'm getting it more and more reliable. This is just one setback...

[mdb4879]

What kind of noise are we talking about?

Is it any easier to pull the transmission than to pull the motor?

[dhen]

I was asking if it would make a noise. I'm not hearing one.

My car isn't a Nissan, and with the setup I have I have to pull the whole engine...

Thanks everyone.

[boost_boy]

Aren't small mods a little messed up on something spinning at 8,000 RPM? What do you mean?

Thanks

I was referring to the holes for the pressure plate to flywheel bolts. Sometimes they need more diameter. If dowel pins don't line, then it is ill-fitting and should be returned. If the clutch plate to flywheel bolt holts are not at least 90% accurate, send the clutch set back to the seller. Minor mods are only that and should not alter the physical dynamics nor the intended balance.

[dhen]

Here's an update:

I pulled it off and found this:









I tried cleaning it with brake cleaner, but it didn't come off.



I ordered a clutch kit to replace it already. Do I need to resurface the flywheel, or can I just take some sandpaper to it?

Should I replace this? The clutch kit came with an extra but the one I have seems fine.



What's this part for? It came with the clutch kit.



I'm replacing both the clutch and pressure plate, but it seems like the pressure plate, not the clutch was bad. The clutch had a lot of material left on it.

[Izento]

The last pic of the small metal circular piece is the pilot bearing and you might as well put that new one in since you are down there. Doing a rear main seal wouldn't be a bad idea either.

The second to last picture where you have the yellow circle drawn around it is called the throwout bearing. You should replace that too with the new one.

As far as resurfacing the flywheel, yes, you need to do it. You have a lot of discoloration on your old pressure plate and swirls on your flywheel. It's better to just spend the $20 to get the flywheel resurfaced.

[dhen]

Yeah, I did some more research on that and I think I will. How do you remove it? I really don't want to break something and pull this engine again.

I'm definitely going to resurface it.

[Izento]

There is a metal clip that holds the throwout bearing together. Just take another upclose photograph of it and take it off, slip on the new one and put it back in. It's really not too complicated of a contraption and you can mostly figure it out just by looking at it, but it's always reassuring to take a picture of it so you can look at it for a double check reference.

[dhen]

Thanks. Will do. Sounds pretty straightforward.

[float_6969]

That clutch was either not cleaned properly before it was installed, or the clutch wasn't adjusted properly and it wasn't fully dis-engagine. LOTS of brake clean when you put the new clutch on. Flywheel MUST be resurfaced. Small round thing is the pilot bearing. It goes inside the crankshaft. It takes a special tool to remove the old one. Use the new throwout bearing. Depending on the kit, you may have to remove the old T/O bearing from the bearing holder with a pulley press and press the new bearing on.

MAKE SURE EVERYTHING IS PERFECTLY CLEAN WHEN YOU PUT IT ALL BACK TOGETHER! LOTS OF BRAKE CLEAN!!!

[dhen]

I installed the XTD clutch. The pressure plate didn't fit. I took it with me when I got the flywheel resurfaced and the shop strongly recommended that I not use the pressure plate since that could throw the engine off balance. They gave me a remanufactured one that "had been resurfaced a few times." It was covered in dust and had obviously been there a while, but you can't argue with free.

He said the part number was stamped on the back. I googled it and wasn't able to find it. Does anyone know what kind of stock pressure plate works on a CA?

Here's a picture:



The throwout bearing was also wrong. I was able to get a new one from Rock Auto for less than $10 that was made in Japan...

The clutch seems OK, but I've only put a few miles on it.

[dhen]

An update:

So I think I might have figured this part number thing out.

When I googled D3500, I got nothing. So I looked up the part number for a pressure plate (Nissan calls it a clutch cover) for a Nissan Pulsar. I got:

Part Number: 30210D4100
This part has been Superceded to: C0210D4104

http://parts.nissanusa.com/nissanparts/ ... _2373=2373

Since the part number I have is DXXXX and the last of the old part number of the Pulsar was DXXXX, I figured the the 30210 was probably just the code for "pressure plate" and the model specific one is the number after d.

Sure enough, when I looked up 30210D3500, I got

Part Number: 30210D3500
This part has been Superceded to: 3021056E06

http://parts.nissanusa.com/nissanparts/ ... 30210D3500

So I think that's my mystery pressure plate.

The stock one that the flywheel shop gave me was sturdier than the XTD one, so the next time I need a new clutch, I'll use a Stanza pressure plate. The flywheel shop said that the clutch disk is the important part on a performance system, not the pressure plate. I think this gives us a lot more options to just get a clutch disk. I measured 24 spline, 1 inch wide in the center and 225 mm on the outside.

I know a KA disk will work. Not sure about SR. A quick search showed that the 2.2 Chevy, a Honda, and Subaru are also options, as they are the same size.

http://www.summitracing.com/search/prod ... r-mm/225mm

Hopefully this is useful to someone.

BTW If someone just wants my crappy XTD pressure plate, I'll give it to you if you pay shipping.