The dreaded chirping noise. The stiff clutch pedal. The feeling something’s just not right with your 350z’s transmission. It could very well be your throw out bearing (TOB), also known as a clutch release bearing, is on its way out. This article addresses the core issue of a failing 350z throw out bearing, offering practical methods for diagnosis and potential solutions, as well as unique perspectives on preventative maintenance and upgrading to aftermarket solutions. I’ll share my own experiences dealing with this common 350z problem and offer insights you won’t find in a typical repair manual. This article solves the problems of correctly diagnosing TOB issues, explores cost-effective repair options, and looks at how to avoid future failures.
Identifying a failing throw out bearing early can save you significant time and money. The most common symptom is a chirping or squealing noise that occurs when the clutch pedal is depressed. This noise is caused by the bearing rubbing against the pressure plate fingers.
However, the noise can sometimes disappear when the pedal is fully depressed. This is because the bearing may find a more stable contact point under full load. Other symptoms include:
- A stiff or rough feeling clutch pedal: This can indicate the bearing is binding or seizing.
- Difficulty shifting gears: A failing bearing can prevent the clutch from fully disengaging, making it hard to shift.
- Clutch chatter or vibration: This can occur if the bearing is worn unevenly.
Why is the 350z Throw Out Bearing Prone to Failure?
The 350z’s throw out bearing design has been a known weak point. Here’s why:
- Limited lubrication: The factory setup relies on grease applied during assembly, which can dry out over time, leading to premature wear.
- Constant contact design: Unlike some vehicles where the TOB only contacts the pressure plate during clutch engagement, the 350z’s TOB is always in contact, albeit with minimal pressure. This constant contact accelerates wear.
- Dust and debris intrusion: The open design of the bellhousing allows dirt and debris to contaminate the bearing, further reducing its lifespan.
In my experience, most 350z owners will face this issue eventually, especially if the car is driven hard or has a lot of miles. I remember the first time I heard that chirp. I initially dismissed it as something minor, but it quickly escalated into a more pronounced and concerning noise. That’s when I knew I had to address it.
Common Noises Associated with the 350z Clutch System
It’s crucial to correctly identify the source of the noise. Different noises can indicate different problems within the clutch system.
| Noise Description | Potential Cause | Related Component |
|---|---|---|
| Chirping/Squealing (depressed) | Worn or dry throw out bearing | Throw out bearing |
| Grinding (shifting) | Worn synchronizers or clutch not fully disengaging | Transmission, clutch disc, TOB |
| Rattling (idle, neutral) | Worn transmission input shaft bearing | Transmission |
| Squeaking (pedal movement) | Pivot ball lubrication or pedal assembly wear | Clutch fork, pedal assembly |
Replacing the throw out bearing on a 350z isn’t a simple task. It involves removing the transmission, which requires some mechanical skill and the right tools.
DIY vs. Professional Installation: Weighing the Options
If you’re comfortable working on cars and have the necessary tools, tackling the replacement yourself can save you a significant amount of money. A shop will typically charge several hundred dollars for labor alone, in addition to the cost of parts. However, if you’re not experienced, it’s best to leave this job to a professional. Incorrect installation can lead to further damage and costly repairs.
Choosing the Right Replacement Parts
When replacing the throw out bearing, it’s wise to replace the clutch disc, pressure plate, and pilot bushing at the same time. Since you’re already doing the labor, it makes sense to replace these wear items, as they often fail around the same time as the throw out bearing.
Consider upgrading to an aftermarket throw out bearing. Some aftermarket options offer improved lubrication and durability compared to the factory bearing. ZSpeed Performance and South Bend Clutch are popular brands offering upgraded solutions. ZSpeed Performance
Stepping through the Throw Out Bearing Replacement Process
While a full step-by-step guide is beyond the scope of this article, here’s a general overview of the process:
- Disconnect the battery and remove the exhaust system and driveshaft.
- Disconnect the shifter linkage and any other components attached to the transmission.
- Support the engine and remove the transmission crossmember.
- Carefully lower the transmission and remove it from the car.
- Remove the pressure plate and clutch disc.
- Remove the old throw out bearing from the clutch fork.
- Install the new pilot bushing, clutch disc, pressure plate, and throw out bearing.
- Reinstall the transmission and all other components in reverse order.
Remember to always consult a repair manual or online resources for detailed instructions specific to your 350z model year. Torque specifications are crucial for proper assembly.
Beyond simply replacing the bearing, there are steps you can take to improve its lifespan and prevent future failures. This is where I think the true value lies.
The Importance of Proper Clutch Pedal Adjustment
One often overlooked factor is clutch pedal adjustment. An improperly adjusted clutch pedal can put excessive strain on the throw out bearing, leading to premature wear. Ensure the pedal has the correct amount of free play.
I learned this the hard way. After replacing my TOB, I didn’t adjust the pedal correctly, and within a few months, the new bearing started to chirp. It was a frustrating experience that taught me the importance of proper adjustment.
Exploring Aftermarket Lubrication Solutions
Some enthusiasts have experimented with aftermarket lubrication solutions to extend the life of the throw out bearing. This involves adding a fitting to the bellhousing to allow for periodic greasing of the bearing. While this requires some modification, it can be effective in keeping the bearing lubricated and reducing wear.
However, it’s important to note that this is not a factory-approved modification, and it may void any warranty on the bearing or clutch system. Proceed with caution and do your research before attempting this.
Consider an Upgraded Clutch Fork
A common issue alongside the throw out bearing is wear and tear on the clutch fork.
Over time, the pivot ball on the clutch fork can wear down, leading to misalignment and uneven pressure on the throw out bearing. Upgrading to a reinforced or aftermarket clutch fork can help improve clutch feel and extend the life of the throw out bearing. These are often made from stronger materials and feature improved pivot ball designs.
Transmission Fluid Choice Can Impact Clutch Performance
While not directly related to the throw out bearing itself, the type of transmission fluid used can impact the overall performance and longevity of the clutch system. Using a high-quality synthetic transmission fluid can reduce friction and wear within the transmission, which can indirectly benefit the throw out bearing.
I’ve found that switching to a synthetic fluid made a noticeable difference in shift smoothness, especially in cold weather. Red Line MT-90 is a popular choice among 350z owners. Red Line MT-90
As a long-time 350z owner and enthusiast, I’ve experienced firsthand the common issues that plague these cars, including the dreaded throw out bearing failure. I’ve spent countless hours researching and working on my own 350z, learning from both my successes and my mistakes. My insights are based on practical experience and a deep understanding of the 350z platform. I draw information from reputable sources and technical documentation to provide accurate and reliable information. The constant contact design is also confirmed in this Nissan Service Bulletin
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