• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Busticated LuK Clutch

tazz said:
which brand clutch are we talking about? The S/B that I have dosen't have springs it has dampers and if I remember correctly ther is only three or four of those.
Click to expand...

The luk disc.

Now you have peaked my interest in the SB with talk about (dampers/dampners/dampeners).

I am beating this to death because I feel the 6.5 disc is weak due to the swiss cheese design with all the spring pockets.
 
So just to chime in here...I am on my second luk clutch with great results. The luk clutch is exactally the same as what you would get from the gm dealer. Luk makes theirs as well. I had one glaze over and start to chatter, but that was my mistake of trying to tow too much weight and slipping the clutch. Ive been happy with them and the price.

As for the damper, my truck came from the factory with the dual mass settup which I replaced with the solid flywheel. I have no damper and all seems well. I thought there was a thread somewhere on here that it wasnt necassary as there was an internal damper on some of the nv4500's?
 
Thanks for the input. How many miles/years of service did the clutch give you & why did it need a replacement.
 
SCREAMINXL said:
Thanks for the input. How many miles/years of service did the clutch give you & why did it need a replacement.
Click to expand...

The first luk clutch I put in lasted me 30K miles of heavy towing and mostly around town driving. It started getting hot spots and chattering, which really began to bother me. Being that the truck is a bit underpowered for the weight id been towing (over 10K), I had slipped it a few times trying to start from a dead stop on hills. When I finnaly replaced it last fall, the clutch discs were not that worn, and probably would have lasted alot longer if not for the chattering. Ive only got about 1500 miles on my newest one as I dont use the truck much in the winter
 
In all reality if the next clutch lasts 55k this pickup will be down the road to another owner. It is slowly going from second string to third. Good heavy duty pickup, makes a good backup or something for me to borrow when I need to pull something the Denali isn't cut out for.
 
Well let me chime my two cents worth. I replaced my dual mass setup with a LUK almost 25000 miles ago towed real heavy for 1000 miles, (29000) Yes that is correct, Combined truck and trailer weight. I have been happy with it, I also added the damper that everyone says you don't need. (YOU DO) It absorbs the high frequency pulse that the diesel generates through your drive line. The pulses tend to break mechanical parts over time, stress fatigue, from the high frequency pulses, if you don;t have something to negate their harmonics, think of it as the Crank shaft damper of the drive line. Now I aint going to argue, you can call me crazy but all the 6.2 had them even the 2 wheel drive solid mass clutches, and I don't have the money to fix a broken handshaker because of a 300 dollar part.

Kind of like a shock absorbers on your vehicle, you can drive without them but something is going to break eventually.
 
Last edited:
SCREAMINXL said:
It most differently pertains to this. Why does the 6.2 SMF clutch disc on have 5 pockets with 10 springs total and the 6.5 SMF clutch has 10 pockets with 20 springs?

I know this statement is headed out to left field but............................what would happen to my drive train if I had a 93 6.2 NV4500 and swapped the tired 6.2 for a fresh complete 6.5 turbo and used the 6.2 clutch? Armageddon?
Click to expand...

So I went onto the S/B and LUK sites today and those disks look nothing like what I have in my truck. Mine has, I believe because it has been a couple of years since install, two springs and the rest being isolators (I found the correct terms for what I was calling dampers) three or four. I was led to believe I was getting what was pictured on The S/B site which was not the case, a disk with a lot of springs and believe me I made a bunch of calls to make sure that I had the right stuff for my truck. So maybe they have changed the design since I installed mine. Just a thought.

Dan
 
Tazz do you think the dampeners you have in your disc are elastometric springs??? I have heard bits and pieces about application with them. You get high force transmission with small deflection. Similar to a high K factor in a steel spring. A spring can be a dampener when you consider it dampening a torque pulse. I am not sure about high frequency vibration transmission. I figure the softer the spring the less transmission of high frequency pulses and why a SMF has a lot more and lighter strenght springs than a DMF. I am guessing a elastometric spring might be a better high frequency dampener due to slower decompression time of the elastometric material ???? I glanced at South Bends website and only saw thier Luk like SMF clutch disc / SMF kit. It appeared to have 2 concentric circles of springs.

I am not argueing with anyone just conversing via the web. Let me back up and say I have interchanged vibration, vibes, and torque pulses (compression kickback / combustion torque) way too liberally in my posts. I think most pulse damage is from low rpm lugging. And do agree with slim high frequency vibrations can fatigue shafts and bearings but I don't know how fast or the severity of transmission shaft vibrations. Or if they are generated the same way. Now I am not so sure high frequency vibes are not created in the transmission on its own and not from the engine crank.

And the DMF might also help dampen the transmission generated vibrations as well as soften low rpm torque pulses but a SMF disc is so soft and the SMF doesn't dampen transmission generated vibes so you add the transmission dampener.

I don't think ( just a intuitive guess ) its anywhere as quick of killer not having the transmission dampener as oprating an engine with bad dampener.
 
I'm not sure about that, really I have no clue. If you go ont the S/B site and look athe clutch for the 01-06 6.6 that is what my disk looks like for the springs and isolators.
 
Well this is a documented case of a busticated Luk clutch with a transmission vibration dampener. I called Josh (chevycowboy) and we were talking about he dampener and he said if you look in the back of the trans you cant see anything if there is one installed. I was like......well I cant see anything so he directed me to his thread

http://www.thetruckstop.us/forum/showthread.php?19594-NV4500-rebuild&p=244576&viewfull=1#post244576

Thanks go to SmithvilleD & Josh.

Here is my brothers trans and the vibration dampener.
attachment.php
 
Last edited:
Clutch showed up today, nothing special, not even a painted pressure plate! Looks similar to the the Luk but has MADE IN CHINA on the clutch disc. What the hell!!!
 
Post up some pics, I'm interested in seeing what this clutch looks like.
 
The last "made in china" clutch disc I had, lasted 4 months. The center spline area broke out, causing the clutch not to dissengage. Of course this happened 1200 miles from home, on the west side of the I70, 11,000 ft pass in Grand Junction, Colorado.

I drove the truck, 11 ft slide in camper and 10 ft enclosed trailer home, 1200 miles without a clutch. I replaced it with a LUK clutch kit. I also needed to have the tranny and transfer case rebuilt, as the input shafts were worn on both from the vibration. The pilot bearing was gone too. :(
 
You must log in or register to reply here.
Back
Top