MidnightBlade
Shiftin' Smooth
Will either size fit the stock DMF or are they different?
11" or 12" clutch?
- Thread starter MidnightBlade
- Start date
mrbison
Registered User
You can probably use either a 11 or 12 inch clutch if you are thinking about replacing it. I know this is true because I just got a 12 inch clutch to upgrade the 11 that needed to be replaced. I went with the 12 inch. I read that its a little better for hauling and other heavy duty applications. I do know that now it shifts great!
MidnightBlade
Shiftin' Smooth
Does your truck have the stock DMF or an aftermarket SMF?
mrbison
Registered User
Mine has the stock DMF. You can get a replacement OEM 11" clutch or a 12" upgrade. Both clutches fit the stock DMF. I put on the 12" clutch and it works fine. I don't really have enough power or do anything extreme enough to need a SMF.
While we are on the subject of SMF and DMF's, here's a nice breakdown of the pro's and con's of both. I got it from here: http://www.high-impact.net/transmission_and_gear/DualMassvsSolidFW.htm
SMF vs. DMF
The dual mass systems are designed to transmit less engine vibration to the driveline, and give a better more car like driving experience. They also reduce some of the jarring and stress on the transmission and remainder of the drivetrain. They work fine as long as the engine remains unmodified and the vehicle is not used/abused beyond manufacturers recommendations.
As soon as you start to increase the engine power over stock, or load the vehicle beyond design parameters, you run into problems. Dual mass flywheels are tuned systems and must be matched to the engine torque curve, engine resonant characteristics, vehicle load curves (including axle ratio/tire size calculations). They work by having a set of springs inserted between two rotating masses (thus dual mass). The springs are sized to soak up some of the resonant vibration from the diesel engine under load conditions. A dual mass fly wheel generally also contains an over torque friction release, so if it gets suddenly overloaded, rather than damage the springs, it slips. This works fine as a safety valve, but if it does it much it burns up. In short, overloaded they burn up and the springs get destroyed and they are worse than if it were a single mass FW.
The single mass part WILL tend to transmit more engine pulse (vibration) tot he drivetrain, and will seem a bit rougher. But it is straight forward to design a single mass flywheel and clutch package for pretty much any engine torque curve and vehicle loading combo you can come up with. Drives more like a TRUCK, but has much better reliability at extreme use levels.
While we are on the subject of SMF and DMF's, here's a nice breakdown of the pro's and con's of both. I got it from here: http://www.high-impact.net/transmission_and_gear/DualMassvsSolidFW.htm
SMF vs. DMF
The dual mass systems are designed to transmit less engine vibration to the driveline, and give a better more car like driving experience. They also reduce some of the jarring and stress on the transmission and remainder of the drivetrain. They work fine as long as the engine remains unmodified and the vehicle is not used/abused beyond manufacturers recommendations.
As soon as you start to increase the engine power over stock, or load the vehicle beyond design parameters, you run into problems. Dual mass flywheels are tuned systems and must be matched to the engine torque curve, engine resonant characteristics, vehicle load curves (including axle ratio/tire size calculations). They work by having a set of springs inserted between two rotating masses (thus dual mass). The springs are sized to soak up some of the resonant vibration from the diesel engine under load conditions. A dual mass fly wheel generally also contains an over torque friction release, so if it gets suddenly overloaded, rather than damage the springs, it slips. This works fine as a safety valve, but if it does it much it burns up. In short, overloaded they burn up and the springs get destroyed and they are worse than if it were a single mass FW.
The single mass part WILL tend to transmit more engine pulse (vibration) tot he drivetrain, and will seem a bit rougher. But it is straight forward to design a single mass flywheel and clutch package for pretty much any engine torque curve and vehicle loading combo you can come up with. Drives more like a TRUCK, but has much better reliability at extreme use levels.
