Upgraded Clutch Slave Cylinder Fails Again!

Davey · 09-18-2015, 06:40 PM

Thanks for updating!

Spooler · 09-18-2015, 09:16 PM

UGG, beat that was ugly. Been there, done that.

Joe@ZSpeed · 09-21-2015, 02:48 PM

Not sure how you could have welded the clutch, A clutch just doesn't weld to the flywheel for no reason.

A clutch welding to a flywheel, esp a organic clutch is nearly impossible, It had to have been uber hot to do this and is only caused be driver error or mis-adjusment of the master cylinder which could cause excessive slipping esp in a racing enviroment.

Like I said in our phone conversation, Send me some pics of it and we can go from there.

Much like your post blaming our slave for failing before you even knew what was going on it seems you are possibly jumping the gun here on the real issue, If the trans has not even been removed how do we know exactly what has happened?

I will be more than happy to help in any way possible but I need info to help.

pbs370z · 09-21-2015, 03:29 PM

Quote:

Originally Posted by Joe@ZSpeed

Not sure how you could have welded the clutch, A clutch just doesn't weld to the flywheel for no reason.

A clutch welding to a flywheel, esp a organic clutch is nearly impossible, It had to have been uber hot to do this and is only caused be driver error or mis-adjusment of the master cylinder which could cause excessive slipping esp in a racing enviroment.

Like I said in our phone conversation, Send me some pics of it and we can go from there.

Much like your post blaming our slave for failing before you even knew what was going on it seems you are possibly jumping the gun here on the real issue, If the trans has not even been removed how do we know exactly what has happened?

I will be more than happy to help in any way possible but I need info to help.

I'm going by what the shop told me. Will let you and all others know for sure when the tranny is pulled. I believe I would have noticed if the clutch was slipping. Also, the pedal had some free play - not at the top.

I did wrongly assume the CSC failed, and I did retract that error. I apologize to anyone I misled.

pbs370z · 09-22-2015, 06:20 PM

9/22/15: Clutch removed today.

Pic1: Press Plate
Pic2: Disk Flywheel side
Pic3: Disk Press Plate side
Pic4: Disk n Press Plate

OK Joe, and any other clutch experts. Whatcha think?

Note: Zspeed HD CSC appears to be good.

Spooler · 09-22-2015, 07:54 PM

What did Southbend say? They are a good company. Can't remember the guys name (Peter???), they are real popular in the Diesel world. Did you contact them?

Boss_302 · 09-23-2015, 09:57 AM

You can see that the disc overheated by the discoloration.
Either excessive abuse, bad pressure plate, in improper adjustment on the throw out bearing - in this case the CSC, or you like riding the clutch.

Spooler · 09-23-2015, 10:04 AM

One question. Were you relying on SRM completely during downshifting/braking zones? If so, you can't because you will do engine braking all the time which is not good for the clutch.

JARblue · 09-23-2015, 10:08 AM

Quote:

Originally Posted by Spooler

One question. Were you relying on SRM completely during downshifting/braking zones? If so, you can't because you will do engine braking all the time which is not good for the clutch.

Are you asking if he was only engine braking through turns on a track and not using the brakes? That would be ridiculous

Spooler · 09-23-2015, 10:11 AM

No, I was asking if he was totally relying on the SRM to REV match for him in the braking zone. You must apply some throttle to limit the amount of engine braking. I noticed an issue at the Dragon when only relying on SRM to rev match.

JARblue · 09-23-2015, 10:17 AM

Quote:

Originally Posted by Spooler

No, I was asking if he was totally relying on the SRM to REV match for him in the braking zone. You must apply some throttle to limit the amount of engine braking. I noticed an issue at the Dragon when only relying on SRM to rev match.

Gotcha!

Makes perfect sense. And yet another reason to practice my spirited driving with SRM off. Although I still have trouble heel-toe in this car with the gas pedal pivot at the floor, and I wind up fat-footing it a lot. Maybe I'll practice some downshifting with SRM on and additional throttle input to minimize the engine braking. Thanks for the tip

Spooler · 09-23-2015, 10:29 AM

You can heel-toe with SRM on. SRM will not be affected. With the Z, you will want to use half your foot on the brake pedal and pivot your other half on the go pedal. It's not really heal-toe so to speak.

Spooler · 09-23-2015, 10:33 AM

Watch Chris Harris with the Porsche Cayman GT4. They have a shot of his foot work in the video. This would be an example.

Joe@ZSpeed · 09-23-2015, 11:04 AM

The clutch was not broke in yet, Not even close.
If you look at the full disk side you can see the dark spots are, This is where the disk was touching the mating surfaces, The lighter areas are where the disk would be touching after it is broke in fully. You are relying on those small areas to hold the disk to the backing.

A facing coming off like that, esp on a steel backed disk where they are riveted and adhered to the steel backing can only happen if not broken in fully, Overheated and over stressed during break in. This is not all that common but can happen with any clutch if not broken in before hard driving conditions.

Since this was just installed, Then tracked shortly after it's a combination of things that can cause disk failure on a "street kit"

We can send it in to South Bend for repair, I'm sure they will take care of it regardless of it not being broke in correctly before raced on.

I would also recommend sending me the CSC so I can take a look at it, When a facing comes off like that the fingers on the pressure plate can be uneven and cause damage internally in the slave.

pbs370z · 09-23-2015, 11:43 AM

I'm no expert but that's what it looks like to me too Joe. I got some bad advice and only broke in the clutch for about 250 miles before tracking and they were not all city miles - combination of highway and city. Not nearly enough break-in apparently. So it does look like it did get too hot in small areas which caused it to fail. Pressure plate plate looks good to me with all fingers evenly matched. Thanks for your diagnosis on these pictures. I'll get back with you. Phil

sent from nowhere significant

09-21-2015, 02:48 PM	#33 (permalink)
Joe@ZSpeed The370Z.com Sponsor Join Date: Mar 2011 Location: Ohio Posts: 1,304 Drives: Nissan Rep Power: 342999	Not sure how you could have welded the clutch, A clutch just doesn't weld to the flywheel for no reason. A clutch welding to a flywheel, esp a organic clutch is nearly impossible, It had to have been uber hot to do this and is only caused be driver error or mis-adjusment of the master cylinder which could cause excessive slipping esp in a racing enviroment. Like I said in our phone conversation, Send me some pics of it and we can go from there. Much like your post blaming our slave for failing before you even knew what was going on it seems you are possibly jumping the gun here on the real issue, If the trans has not even been removed how do we know exactly what has happened? I will be more than happy to help in any way possible but I need info to help. __________________ Phone *937-506-7224* E-Mail Sales@Zspeed.com www.ZSPEED.com

09-23-2015, 10:11 AM	#40 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	No, I was asking if he was totally relying on the SRM to REV match for him in the braking zone. You must apply some throttle to limit the amount of engine braking. I noticed an issue at the Dragon when only relying on SRM to rev match. JARblue likes this.

09-23-2015, 11:04 AM	#44 (permalink)
Joe@ZSpeed The370Z.com Sponsor Join Date: Mar 2011 Location: Ohio Posts: 1,304 Drives: Nissan Rep Power: 342999	The clutch was not broke in yet, Not even close. If you look at the full disk side you can see the dark spots are, This is where the disk was touching the mating surfaces, The lighter areas are where the disk would be touching after it is broke in fully. You are relying on those small areas to hold the disk to the backing. A facing coming off like that, esp on a steel backed disk where they are riveted and adhered to the steel backing can only happen if not broken in fully, Overheated and over stressed during break in. This is not all that common but can happen with any clutch if not broken in before hard driving conditions. Since this was just installed, Then tracked shortly after it's a combination of things that can cause disk failure on a "street kit" We can send it in to South Bend for repair, I'm sure they will take care of it regardless of it not being broke in correctly before raced on. I would also recommend sending me the CSC so I can take a look at it, When a facing comes off like that the fingers on the pressure plate can be uneven and cause damage internally in the slave. Zbrah likes this. __________________ Phone *937-506-7224* E-Mail Sales@Zspeed.com www.ZSPEED.com

09-23-2015, 11:43 AM	#45 (permalink)
pbs370z Base Member Join Date: Jul 2010 Location: Near Portland, OR Posts: 92 Drives: '10 370Z, Sport Pkg Rep Power: 3369	I'm no expert but that's what it looks like to me too Joe. I got some bad advice and only broke in the clutch for about 250 miles before tracking and they were not all city miles - combination of highway and city. Not nearly enough break-in apparently. So it does look like it did get too hot in small areas which caused it to fail. Pressure plate plate looks good to me with all fingers evenly matched. Thanks for your diagnosis on these pictures. I'll get back with you. Phil sent from nowhere significant __________________ '10 Z, Sport Pkg 6 MT, Stillen Brake Cooler, Z1 Oil Cooler w/Setrab 25 row/Mocal T-stat, Southbend Clutch w/light wt Flywheel. Last edited by pbs370z; 09-23-2015 at 11:47 AM.

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09-18-2015, 06:40 PM	#31 (permalink)
Davey A True Z Fanatic Join Date: Apr 2011 Location: Indiana Posts: 3,766 Drives: '15 NISMO 6MT Rep Power: 117171	Thanks for updating!

09-18-2015, 09:16 PM	#32 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	UGG, beat that was ugly. Been there, done that.

09-22-2015, 07:54 PM	#36 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	What did Southbend say? They are a good company. Can't remember the guys name (Peter???), they are real popular in the Diesel world. Did you contact them?

09-23-2015, 09:57 AM	#37 (permalink)
Boss_302 Base Member Join Date: Feb 2013 Location: NY NY Posts: 150 Drives: 11 Nissan 370z S Mt Rep Power: 12	You can see that the disc overheated by the discoloration. Either excessive abuse, bad pressure plate, in improper adjustment on the throw out bearing - in this case the CSC, or you like riding the clutch.

09-23-2015, 10:04 AM	#38 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	One question. Were you relying on SRM completely during downshifting/braking zones? If so, you can't because you will do engine braking all the time which is not good for the clutch.

09-23-2015, 10:29 AM	#42 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	You can heel-toe with SRM on. SRM will not be affected. With the Z, you will want to use half your foot on the brake pedal and pivot your other half on the go pedal. It's not really heal-toe so to speak.

09-23-2015, 10:33 AM	#43 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,509 Drives: 2013 Nismo 370z Rep Power: 2684391	Watch Chris Harris with the Porsche Cayman GT4. They have a shot of his foot work in the video. This would be an example.