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Discussion Starter #1 (Edited)
The Gen1 Cruze clutch has been reported as feeling numb. Furthermore, the car suffers from shift grinding, inconsistent shifting, and notchy/hard shifting, especially during spirited driving and rapid shifting. This thread will address these symptoms with solutions for addressing the root cause.

The Manual Transmission Fluid
As noted in the Cruze Manual Transmission (M32) Issues thread, the manual transmission fluid on these cars is too thin, which causes shifting issues when the transmission gets hot. The two AMSOIL fluids greatly improve shifting quality. Links for those products are available in that thread. However, the fluid is only part of the problem.


The Nanny Clutch
I've affectionately named this the nanny clutch, because it tries to save you from your silly self. In other words, GM designed this to prevent drivetrain shock in the event that a newbie slipped his foot off the clutch and shocked drivetrain components, in order to reduce warranty claims. The flipside to this is that everyone HATES how this clutch feels and how the car shifts. Fortunately, we have finally come up with a solution. I've partnered with BadNewsRacing.net to develop a solution. However, I'd like to explain how the stock system works.

There are two components to the stock clutch line to discuss; the clutch delay valve (more accurately a restrictor orifice), and the accumulator. The delay valve is really just a restrictor that restricts the amount of flow going out of, but also into the clutch. In other words, no matter how hard you press on the clutch, only so much fluid will flow through it. Naturally, you can guess how this ends up working out for you. If you let off the clutch quickly, the clutch will only allow fluid to come back at a certain rate, which means that as you're trying to power shift into the next gear, your clutch isn't fully disengaged from the flywheel, and you hear that oh so familiar GRIND into the next gear. This is worst with the 1-2 shift gear change. There's a tutorial on how to remove this. You simply disconnect the clutch line, remove the clutch delay valve, and push the line back into the transmission and clip it without it. GM made this easy for us by making the clutch delay valve essentially a male and female replica of the clutch line itself. Here's the tutorial:

https://www.cruzetalk.com/forum/129-gen1-engine-transmission-tutorials/185322-how-remove-clutch-delay-valve-cdv.html

The second component is the accumulator. Now, if GM had only left the clutch delay valve in place, your clutch would feel unnaturally spongy and soggy, so in order to improve clutch feel, they added an accumulator to absorb excess clutch pressure while the clutch line waits for clutch fluid to flow through the clutch delay valve. This means that any time you mash the clutch pedal to make a quick shift, much of that clutch fluid is actually being absorbed in the clutch fluid accumulator instead of going to the clutch slave cylinder to disconnect the clutch from the flywheel! The second part of fixing this nanny clutch is to bypass that system entirely. My brother and I designed a bypass mod, and I've partnered with BadNewsRacing to distribute this to the community. You can purchase the mod here:

2011-2016 Cruze Limited Clutch Accumulator Bypass

The tutorial to install this is located here:

https://www.cruzetalk.com/forum/129-gen1-engine-transmission-tutorials/236179-how-install-clutch-accumulator-bypass-mod.html#post3189899


The End Result
Once you've bypassed the clutch delay valve and installed the clutch accumulator mod, the stock clutch accumulator no longer absorbs clutch pressure, resulting in fluid being pushed directly into the clutch slave the moment your foot hits the pedal, at any speed. This results in faster clutch disengagement for butter smooth shifts during spirited driving and a greatly alleviated (if not totally cured) 1-2 shift grind, except for those moments when you don't press the clutch fast enough of course. Since the clutch line no longer has any accumulator or restriction, these mods also greatly improve clutch pedal feel. It is no longer as numb and lifeless, and allows for better clutch control, more comfortable driving, and more accurate shifting.

These upgrades make such a big difference on the Cruze that I strongly recommend everyone with a manual transmission perform these upgrades.


Disclaimer
Naturally, these nanny mods to an otherwise fine clutch system are there to save you from yourself. Neither myself, nor CruzeTalk, nor BadNewsRacing hold any liability for any damage caused to your engine by the installation of any of these upgrades. If you slip your foot off the clutch at a max RPM shift and grind a gear, break an axle, or who knows what else, that is all on you. Make sure you are comfortable driving a manual transmission before performing these upgrades.


Happy Shifting!
 
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