New product review: CSC bearing sleeve for aftermarket clutches

Zat_Zuma

Let me start by educating the minority and explaining how a Concentric Slave Cylinder (CSC) works on a 2007-09 3.5 HR and 2009-10 3.7 VHR. It is a hydraulic cylinder that pushes on the pressure plate fingers to release the pressure on a clutch and allows the driver to shift gears.

It's construction is simple and straight to the point. Hydraulic pressure expands in the cylinder pushing the CSC bearing plate towards the fingers of a pressure plate and releases the pressure on a clutch. What you probably didn't know that it does this within a 15 mm stroke (just slightly over a 1/2" for the metric measurement challenged). I suspect full clutch disengagement is done within 10 mm. 15 mm is probably considered over extending the CSC and eventual failure.




The CSC rides and maintains a slight pressure on the pressure plate fingers at all times and as a result rotates roughly the same RPM's as the engine. The CSC face is made from a hard steel to prevent wear and to withstand the abuse of it's environment. It has a bearing surface width of 7 mm and inside diameter of 48 mm.

The OEM pressure plate has knurled fingers to allow to work properly on a flat bearing surface on the CSC. The pressure plate fingers have a opening of 49 mm and therefore makes excellent contact with the CSC bearing surface.




Now getting to the bearing sleeve for aftermarket clutches. Speed Performance has done some research on the relationship between the CSC's and the latest aftermarket clutches available for our 370Z's. They have developed a bearing sleeve for the CSC to correct the contact pattern on the aftermarket pressure plate fingers and corrected the spacing problem concerned with over extension of the CSC stroke. It is a thing of beauty




stock CSC for comparison




Now for the shocker ...........

I just happened to have a popular clutch/flywheel/ pressure plate combination on hand to compare the differences in CSC fitments. I won't mention the manufacturer but needless to say some members have this installed in their cars right now. I for one, will NOT be installing this into my car. after seeing first hand the CSC fitment and quality compared to a Speed Performance clutch offering. The space between the fingers of the un-named aftermarket pressure plate is 57.5 mm.
Let the pictures speak for themselves.

Aftermarket with stock CSC



As you can see the fitment is horrible and there is next to nothing for contact on the CSC bearing. It's a recipe for failure.


Aftermarket and CSC with bearing sleeve




For the record I did purchase a Speed Performance Stage 4 clutch package, solid steel flywheel, pressure plate and CSC with bearing sleeve with a stainless steel clutch line to eliminate the orifice block in the stock line. I had way too much trouble with the stock CSC and clutch lines on my 2007 3.5 HR with a aftermarket clutch not to replace the stock clutch lines and remove the orifice.



I'm looking forward to the install.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

wheee!

Very cool! Make sure you post it up as a DIY for clutch replacement!

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RCZ

amazing + 1 rep.

What was the cost of everything combined?

Zat_Zuma

The cost was just over a $1000, which is comparable to everyone else. It included the HD billet 1 piece steel flywheel; Stage 4 clutch with Feramic on one side and organic on the other, rated to 600 Torque; HD pressure plate with a really thick clamping plate; CSC and bearing sleeve; and a 1 piece stainless clutch line from the master cylinder to the clutch. Overall, not a bad price considering the quality of everything.

Just had a conversation with Speed Performance yesterday, and apparently a new metal CSC will becoming available within a few weeks to replace the plastic stock CSC. It looks promising.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

Zat_Zuma

Won't be doing that.

This is one job either you know how to do it or you pay someone who does. It's not for the average DIY'er

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

NewYorkJon34

I know others that have the jwt clutch/flywheel without the csc part, so is this part "really" necessary for switching out the stock clutch for the jwt set-up?

kevin.z

^good question. I am lookin forward to the answer as well.

Prosport Gauges

omg south bend clutch FTL. Had one in my suby and the thing was horrible. It was a 6 puck.

Clutch made a rather horrible engagment sound. no it wasnt clutch shudder.

Found out the pressure plate was a defect from them.

Customer service was rather poor

The OEM throw out bearing broke so i had to take everything apart.

I had a nightmare with this company.

Zat_Zuma

I've given you the measurements of the stock CSC and the diaphram on the stock and aftermarket pressure plates without a brand name. It's easy to do the math

Basically, in my opinion, any aftermarket pressure plate with a DE style diaphram with a gap larger than 49 mm will need the bearing cap for proper contact between the CSC and diaphram fingers. The JWT is a DE style pressure plate.

I'm hesitant to point fingers at brand names as vendors in this forum have installed those brand names in cars with stock CSC's and say there ok. I'm not here to point fingers and say they are wrong but just report my findings and say what I've decided to do with my car. It's up to the individual to make there own conclusions and choices with the information they have collected.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

Xan

If you think 2.25mm is enough for contact, while the OEM designed contact is 6.5mm... then you should be good.... I have to agree with the OP... seems like asking for trouble...

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Zat_Zuma

I know I had a JWT flywheel, clutch and pressure plate, dealer installed, in my 2007 3.5 HR and had nothing but grieve and problems with clutch hydraulics. I didn't want a repeat performance with the 370Z.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

NewYorkJon34

It sounds like I'll be needing this part whenever I upgrade my clutch, I'm all about doing things right the first time so there wont be any nasty suprises in the future. Where can we order this part from? And how much is it going to cost?

Zat_Zuma

I got my parts at:
350Z HR High Rev Concentric Slave Cylinder bearing adaptor sleeve

Just tell them I refered you

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

NewYorkJon34

Awesome, I'll def be sure to pick one up when I switch clutches. Which clutch/flywheel brand would you suggest? I plan on having the GTM stg.2 supercharger installed & tuned to about 550whp+. I was thinking either the Southbend or JWT clutch/flywheel package, but if you could suggest something else that would be great.

RCZ

Jon, he recommends the South Bend clutches. Specifically the stage 4 one which costs around $650.... then you have to think about the flywheel which is $500 more and then you have to add the CSC fix...which will be somewhere around $60?

As of right now...thats what I'm doing..