I have finally had the time to post pics about the original install of Craig McElfresh's single mass flywheel and dual disc clutch kit. This thread

http://www.dieselplace.com/forum/showthread.php?t=20922

shows some pics of Craigs removal and examination of this kit.

this thread will start with some stock parts pics. the last pic compares the oem clutch with one of the two dual disc plates.

install - posted backwards -sorry :confused:

Craig's flywheel installed - last pic shows crankshaft and flywheel alignment pin

let me know if you got any questions. good luck to any new installs !!!!!!!!!!!!!!!

Deadeye
Just a few questions:
How do you like this new setup?
Does it make a lot of noise?
Did you do the install yourself and how long did it take?
Thanks for the great info.

WOW! Must be a totaly different feel on the pedal.Either engaged or disengaged and not much inbetween.That clutch aint gonna slip.COOL!

Str8 Eight, jon72;

Like every coin you have ever seen, there are two sides. The kit was lots of $$ (~$2300) the install, since it was first time, took me and mostly two buddies 17 hours (with two stops for meals) to complete. The clutch pedal is harder to push than stock but it has never gotten HARD since it does no slipping at all. In idle with the shifter in neutral and the pedal out, their is some noticeable rattle, but not as loud as you would notice on a ford or cummins. The clutch is like gears. They hold tight and are tricky to shift without squeal, esp when starting from a complete stop. Almost always makes a high freq. short squeal and sometimes a couple of jerks when engaging. The clutch plates are made mostly of steal so you can imagine what the squeal and jerkin' is like. Periodically, I have to do a high rpm launch for 3rd gear from a stop and let the pedal out partially to slip the clutch. This smooths out the surface and eliminates the squeal and jerkin' for a while. . . depends on how much stop and go drivin'.

I did a recent dyno day with HJAT at lvl 5, Quad 110 stacked, NOS and propane and the clutch did not slip at all. I really like the strength of the clutch. It should last forever unless I do a lot of drag launches or sled pullin'. Then some shims will need to be removed to prevent slippin'. Drivin' in stop and go traffic is not fun with this clutch.

Now you can see both sides of this coin. I would still do it over again, knowin' what I know now. My truck transfers more torque to the wheels than an identical one with an upgraded Allison. However, shiftin' is not near as quick as the Allison so draggin' against an auto tranny will be hard.

Deadeye are you saying it shifts slower than stock clutch?Or just slower than an Allison.With that kit can you run just one disc?Looks like you could.I dont think the dual disc would bother me much but I gotta do something pretty quick.One thing I aint gonna do is put DMF and stock clutch back in.Thanks for the info!!!

Craig does have the same clutch only single disc with a spacer. The dual disc is a pain in the butt in traffic. It is very tricky when I have a big load on the trailer and start on a hill. The first disc engauges and then releases with the minimal pressure on the disc. As the pressure comes on both disc there is very little if any slip. Your either going or your not. I have a few hooks on the clutch one being extremely hard on it. The squeal is not that big a deal and not all the clutches will do that all the time. If you are not planning on pulling I would go with a single as it is a kevlar disc.... IIRC. One thing for sure is that you are not going to slip this clutch with the power a Dmax can make as of now. When you can put 500hp ish to 3500 RPM and walk the clutch for 50 to 100 ft and still have it hook up... you got a clutch:ro) :ro) . I'm sure this clutch will hold more than the drive shaft wants to. Bottom line is, it is a very heavy duty clutch, but with that comes some driveability issues. It all depends on what you want to do. Not to make you feel bad, but Craig did my install with minimal help from me in 2 hours and 10 min, but he is a trained professional.

jon72;

I agree with Gray Max. hope this answers your concerns. And yes, the shifting is a little stiffer than stock and not as fast as Allison.

Not to make you feel bad, but Craig did my install with minimal help from me in 2 hours and 10 min, but he is a trained professional.
Doesn't make me feel bad in the least!!! LOL, I think it would have gone a little quicker had we actually removed the last bolt holding the tranny to the motor at the very top. And we had to do some minor mods to the flywheel as the locator pin hole was just a little too small, that really put a kink in things!!!

All in all it was fun putting it in, although a 2 hour install would've been nice!!

it has never gotten HARD since it does no slipping at all

Slipping the clutch makes the clutch feel hard?
I'm assuming it's because the heat distorts the pressure plate fingers (or some part within), sorry I have little experience with hand shakers, so I'm just trying to learn.....

I have replaced clutches before in pickups and trying to figure out what would cause the pedal to get hard. Pushing with your foot either operates a mechanical fork on a pivot (in the old days), and a master/slave in a newer hydraulic setup. That would in turn push on the throwout bearing which puts pressure on the "fingers" to release the clutch. Because this is a hydraulic setup I don't think the problem would be in the "linkage" or lack thereof, and it doesn't seem like the fluid is an issue as clutch replacement fixes it, so the only thing that would seem to cause extra pressure or resistance would be the throwout bearing or Pressure plate fingers......or am I way off here?

Can't tell you for sure but I have never had the pedal get hard since Craig's kit was installed. On the other hand, everytime I slipped the stock clutch (rpms jumped and spedo stay the same) the pedal would get hard. I 'stand' on the pedal and it would go down but would then haave to pull it up with my toe. Afther that it worked until it slipped again. I am thinking the slippin caused heat that caused the slave cylinder to get hot and "push back" on the hydro fluid?????