Different Clutch Engagement After Tire Change
 

I own a 2012 370z sports package model that I drive daily. I have owned the car since 06/15/12, and have put slightly over 18,xxx miles on the odometer in a little over 8 months. :driving: My Z is on the road a lot. On Tuesday, 02/19/2013, I installed my BC BR coilovers by myself with no problems whatsoever after work (BTW, I made a how-to video on the coilover install coming soon to the DIY thread). Drove the car the rest of the week with no problems. Then I had my original Potenza tires replaced on Saturday, 02/23/13, with Nitto Invo's. Went up one size to a 255/35/19 front and a 285/30/19 rear. Now, I noticed after the tire change that my clutch feels completely different. My Z of course is losing traction under moderate acceleration with my VDC engaging due to the mold release agent on new tires. I know that is completely normal. But the engagement of the clutch feels completely different. The clutch is engaging much lower than before and during some shifts it feels as if it wants to catch halfway up, so when I release the clutch fully it pops up to the disengagement top position. I really am confused. :confused: I have previously owned a 2003 350z and a 2008 350z both of which were 6 MT's driven daily with no clutch issues at all. Could the coilover install affect my clutch engagement? Car is only lowered 1" all the way around. I was going to wait another two weeks before having the car realigned to allow the new suspension time to fully settle. Could the change in tire size cause a complete difference in clutch engagement? Any feedback would be greatly appreciated!

Did you watch them as they installed your tires? Wondering if they took your car on a joy ride and burnt the clutch.

I feel the coilover or tire change has nothing to do with it. Just a coincidence most likely. If you do in fact have clutch engagement difference I'm going to say the CSC or MC is starting to act up. Especially with the mileage. Which seems to be common.

But start with bleeding the clutch then go from there. You still under warrenty so no worries.

I agree with spohn, coils have nothing to do with it. make sure you're topped off on fluid and look for leaks around your master and slave cylinder, and/or bleed the system.


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Unfortunately, Porterfield Tire in Athens, GA is big tire shop, and they were slammed on Saturday morning when I got there. So I had a friend of mine pick me up while they swapped my tires. Customers are not allowed to go into the install bays, and they are not clearly visible from the waiting area. I would not have been able to watch even if I would have been there. But, I did have the same idea initially too............

Thanks Spohn, that is fantastic news! This is exactly what I was thinking too. Would the increased tire size or lowered suspension void my factory warranty though? I bought the car from Sutherlin Nissan near the Mall of GA, and everyone there is crooked in my opinion. Any trustworthy Nissan dealerships that you would recommend since you are in Ga too?

Thanks Huck, I will be giving this is a try in just a bit. I appreciate your help as well!

No that shouldn't effect anything. But I've been told Gwinnett Nissan is great.

Dealership
 

I have one experience with them, and it indeed was a great one. Good call, I will give them a try again. I will keep you guys updated. Thanks again for your valued input.

Like Spohn said :tup:

I have the exact same tire set up ... no issues. I love these tires for the price :tup:

Nissan warrantees the clutch parts? Never heard of any manufacturer that does that.

I have always used Capital Nissan and not had any problems, if you call or go ask for Doug.

Yes they will warranty CSC and MC. They make the clutch work. They are not actually the clutch parts. Those two item have been common failures on our car.

What I see most often is the tech rev the engine and slip the clutch to get it on the lift "cautiously". Many of them don't drive a stick well and will not admit that fact in the "shop"

It's less likely that they took it for a joyride.

Clutch Issue
 

Just to let everyone know the clutch actually feels normal after warming the car up and driving it after about 10 minutes. It just feels "spongy" at first. That really is the best way to describe it. I have called Gwinnett Nissan, and they too say it sounds like the CSC. I have an appointment to bleed the clutch. Sounds like quite the PITA, and I do not want to void my warranty by messing something up. So I am just going to let them do it. Thanks again for everyone's input!!!!

Yeah, the tires are awesome! Really enjoying them.

Thanks for the heads up. I will keep them in mind too.

Of course I automatically assume the worse when I noticed the problem. I have dealt with this tire shop on a number of occasions, so I don't think they would do anything to my car, and I totally agree. Most techs are horrible at driving manuals. Lol!

Is not the clutch.
 

Look at the clutch pedal. There is a spring/piston assembly on top of the pedal. What it does is helps when engaging the clutch by helping (it's like giving a boost) you pushing on the pedal. It only works for the first (20% to 30%) of the clutch level travel. If you press it by hand you can see, it only helps you with the initial push of the cluth pedal, after that is just leg power. When releasing the clutch is has an effect thus giving you an "inconsistent feel". I removed mine, the pedal feels now a bit harder but is always consistent.
I could be wrong, but that help my "inconsistent clutch engagement".