Simple Clutch Diagnostics with RAM Clutches Team

Clutch Complications? - RAM Clutches gives us valuable insight on performance variations and expectation

D.J. Randall May 13, 2014 0 Comment(s)
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Power Adders

Adding nitrous, a blower, or a turbocharger (or two) to your beast will impose an instant load on the clutch system. Once that stock clutch wears out quickly, make sure to always select an aftermarket clutch system with a higher horsepower rating, than your current power level, or your anticipated level. Selecting a clutch system that is under rated ensures premature wear, and is obviously why your stock clutch won't last.

Larger diameter clutches or clutches with more aggressive friction materials, (higher coefficient of friction) for example, like metallic materials, will address increased loads better. Alternatively, stepping up from a single disc to a dual disc setup will also help to address those increased loads.

If street time is limited and track time becomes the priority, it would be advisable to select a dual-disc clutch at the onset. Dual disc setups will transmit higher torque loads more efficiently, helping to dissipate the heat, and will function properly, for a longer timeframe.

Driving Habits

Not to point fingers, but simple driving habit changes can prolong clutch life, while halting premature wear. Take a look at these three tips on how to avoid clutch troubles at the drag strip, from the professionals at RAM Automotive Company:

First, disable the traction control to eliminate the risk of introducing extreme loads to the clutch system, inadvertently. Some traction control systems apply the brakes, while others use rapid ignition retardation that affects the clutch.

Second, remember to select a low gear. Even professional racers have launched in second and third gears, all stressing the transmission and clutch.

Third, ensure the rear tires are positioned in the water. As you exit the water, depress the clutch pedal before they reach dry track surface. Following this advice avoids transmitting stressful, and severely damaging, loads through the clutch system and drivetrain. Speaking of stressful loads, let's look at signs of wear, in a Q and A between the pros at RAM Clutches, in the pictures below:

10 5 Inch 2/9

Q: This 10.5-inch clutch is pretty hammered, so what went wrong?
A: Possibly, a single disc unit was selected, but more clutch was needed. Driver error could also be to blame. However, there could’ve been installation issues. If the fingers of the clutch are shiny or worn, the release bearing could have been adjusted too close to the fingers, and as the clutch wore in, the bearing unloaded the clutch.

Clutch Fingers 3/9

Q: Do the oblong marks on the clutch fingers, where they made contact with the bearing, appear normal?
A: The wear on the tips is fairly normal, and if there were a lot of flat spotting, it would indicate the bearing is riding the fingers from maladjustment, or from the driver ridding the pedal.

Q: What is the most important precaution, to ensure this misalignment is avoided?
A: Concerning mechanical/cable release vehicles, having the bearing adjusted too close to the fingers initially, when the wear occurs, the bearing will end up ridding the fingers and unload or slip the clutch. On hydraulic setups, too much preload on the bearing may cause it to bottom out rearward and unload the clutch.

Q: Why is there fabric caught between the fingers and the cover body? Presumably, the black dust conveys something ominous?
A: Simply, this is caused by the severe wear that has taken the friction material right down to the fiber and it has gathered around the fingers.

9 5 Inch 4/9

Q: Is this a single 9.5-inch that was subjected to forces better suited for a 10.5-inch? Are there any other symptoms (smell, audible, visual—maybe lots of black dust) that should have alerted the user that things weren’t well in the clutch department?
A: The smell of the unit for sure, the driver may have even been getting some black dust out of the bell housing. The parts tell the same story, and this setup must have been slipping almost non-stop. The driver needed more clutch.

Single Setup Clutch 5/9

Q: So this single setup is very much warn, and here’s the reverse side, but when you said, “The driver needed more clutch,” do you mean he needed a dual-disc or are there other alternatives you have in mind?
A: I was thinking of a dual disc or if the vehicle is more of a racecar, perhaps a proper racing clutch.

Clutch Fingers Closeup Flat 6/9
Clutch Fingers Closeup Flat Spotting 7/9

Q: Do these pictures of the fingers of this clutch suggest an overly close bearing?
A: Notice the flat spotting.  Normally, the finger would be rounded off along the contour of the lever tip.  Potentially, it could be just from a constant riding of the pedal by the driver. Poor adjustment is a common mistake that individuals make when installing a clutch.  If you do not leave bearing clearance, as the disc wears, the fingers move back or get taller, and can ultimately bottom out of the bearing, and cause it to unload the clutch.

Sources

RAM Clutches
Columbia, SC 29203
803-788-6034
www.ramclutches.com

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