Anyone heard of this clutch

[MCummings]

We are running the: NMU70119-04 12 x 1 1/4 Ceramic 5 Speed Dodge

The clutch hub is not strong enough to hold abuse on teh 12. 25 clutch.



Heck, Even I tore the center out of a 13"er.



I have a Dual disk now, and I'm feeling it out. So far I haven't been able to get it mad at me.





Merrick

 

[wawazat]

Question for you Zoom ZVT users. I had one installed yesterday. Shifts nicely but with the truck in neutral and the pedal released it rattles like CRAZY until the revs come up a little. This is unacceptable for me and how I use my truck (customers and others in the truck with me regularly) and I am returning it shortly. Has this been your experience too brayls?



GCroyle-I tried calling you to get the inside scoop but your voice mail message says you are out until 7/31. Truck is out of commission and I cannot wait to hear from you over the phone. I'm hoping you'll see this and give me your thoughts. Your tech service guys and engineers who back them up did not leave me with a warm fuzzy when I called with questions. Summit racing has been very helpful however

 

[MCummings]

Sounds like it's a un-sprung clutch.



My dual-disc is the same way.



Merrick



EDIT: This stage 3 clutch will be very noisy down near idle, and low RPM. Even when idling that clutch will make some big rig rattle. Because it is not sprung, it does not have the ability to dampen the RPM spikes while the engine is running, so it gets "thrown" back and forth on the input shaft splines.

 

[nickleinonen]

Sounds like it's a un-sprung clutch.

the zvt from the pictures has a spring dampened hub...

#ad


might be the 4 weights/levers on the pressure plate making the noise [not enough centrifical force to keep them planted against the pressure plate]



???

 

[GCroyle]

wawazat,



I sent you a PM.



We are using a simple but strong damper design that does not have the Pre Damper or Idle Stage Damper element that is used in the OE designs. We went for durability, strength and simplicity. In 4th for a 5 speed or 5th for a 6 speed, under load, you can hear a bit of gear noise that is created in the transmission, shift up and it's gone. Also at idel without the predamper, you may hear some gear noise because we are not using a pre-damper.

 

[South Bend Clutch]

wawazat,



I sent you a PM.



We are using a simple but strong damper design that does not have the Pre Damper or Idle Stage Damper element that is used in the OE designs. We went for durability, strength and simplicity. In 4th for a 5 speed or 5th for a 6 speed, under load, you can hear a bit of gear noise that is created in the transmission, shift up and it's gone. Also at idel without the predamper, you may hear some gear noise because we are not using a pre-damper.

You are right. When I developed this disc back in 1999 for the Ford Powerstroke, it was a quick cheep easy fix for the premature spring failure they were having. This spicer design disc is used in the semi's, I just had to shrink it down and make a hub to fit the 1 3/8" shaft. This hub was not available then. You can see a picture of this disc that has been on my webpage for 7 years now... .



http://www.southbendclutch.com/6sphdceramic.html



However, one thing different with our disc is it has a free travel design. This means the springs and hub will rotate back and forth within the drive plate of the disc. It is a brute of a disc but we knew that the majority of the people would not tolerate the neutral rollover (noise) and the long term damage that will occur to the sincros of the transmission. We do still offer it but try to only use this design for the extreme heavy haulers. We always inform them of the problem with this design. Some will opt to use it where the majority will ask if there is any other options. A floating hub is critical for the diesel pickups unless the truck is used outside its intended perimeters.



Peter

 

[GCroyle]

ZVT Disc

To All,



Our disc is the free floating design, and the relibality of this type of disc has proven itself in unknown millions of highway commercial service miles.



I have to get on a plane, will submit more information later.

 

[BRayls]

disk is not as quiet as the stock one. quieter than the dual disk though. those running them will tell you of their noise. my truck was to be at tst tuesday 9am. lost the starter ,hope you don't not cheap or close to here 4-5 day wait. it is star restricted have to go through the process ,even paying out of pocket like me. we'll see when it gets here when I can get down there( or the dyno is open I should say). if its here monday I will see if the dyno is still open. I never said anything bad about the sbc, other than pedal pressure, and you all know thats high. dyno will tell us if it is slipping in the lower rpm's. but Gary says the weights have come fully in by 1500 rpm so its pretty low that the clamp is there. in my testing it is doing great and I am at 18,000 miles of hard use.

 

[GCroyle]

Clutch Disc Functions

To All,



A clutch disc has many separate functions and several design systems are commonly used to achieve the desired results. This discussion is focused on torsion dampers. A torsion damper is the series of coil springs, friction washers, wave springs bushings and other components in the center section of a clutch disc. In our Dodges we have had several design variations but the damper has two major functions, "This helps to eliminate torsional vibrations and/or shock loads from being transmitted from the engine to the transmission, or shock loads from being transmitted from the driveline to the engine" (Manual Transmission Clutch Systems SAE publication, AE-17 page 42, Dampened Disc defined). One of the most challenging jobs for the clutch disc is to satisfy the requirements for an application as far as a torsion damper, this is where we need to tip our hats to these talented engineers at the OE suppliers for their work. Now the aftermarket supplies clutch systems to meet the needs of those who demand more, that is one of our jobs. We all seem to want a little bit more from our trucks and our ZVT systems offer high torque capacity, driveability and performance, but with the "basic" torsion damper that we have chosen, we can't have the identical cab enviroment that the OE disc has, so its a trade off or compromise. As far as transmission syncronizer wear, if your system shifts cleanly, and the inertia of the clutch disc is not excessive, syncros only see wear during shifts, as soon as the gear is selected, the syncro has matched gear speeds and is no longer "active" If you would like to hear your gear noise, heat up the truck, pull next to a brick wall, roll the window down, select neutral and slowly engage the clutch, then disengage and repeat. You will hear whatever noise the transmission is making as rollover or gear noise. Remember Ford chose a DMF to get the job done for them and now the G56 has one and it looks a whole lot like the D-Max design, and Ford conversions from their DMF to a solid flywheel design are one of tour most popular sellers.

 

[BRayls]

I too wondered about the synchro thing, as the dual disk is heavy and also causes just as much wear on them. doing my research before doing the clutch in my truck. I was told ,and not from Gary or perfection, that it will make the same wear as the dual disks out there and that might be 1000 miles off 100,000. we'll see. I can say this ,most of us needing either of them really should expect to rebuild them before that .