shlen

Please read “S-Bend, anybody else have this problem?” for the initial problem.

The noise and issues with this clutch were getting absolutely crazy...SO...went into the clutch for the 4th time and pulled it out of the truck. As you can see by the pictures the clutch has a major design problem. The "polyurethane bumpers" just fell out. You can see them sitting there at the bottom of the housing. Only one actually stayed in long enough to get squished and then fall out, the rest look new. I am not an engineer but you can see the gap is about พ of an inch and you can see the holes were the polyurethane bumpers were supposed to be. I guess, think of it like a set of those “time waster” ***** you have on your desk...you know the 5 chrome ***** that you pull up on the right one and it swings back, then it collides with the other four then the left one swings. The larger the gap the more force that is transferred back and forth. Same with this clutch...thus the noise. Why can’t the gap be closed to a 1/16th of an inch or whatever allows for heat expansion and then instead of being square cut the edges at 45 so the plate key seats in the other plate? Less movement, less noise. Let me reiterate I am not an Engineer.

Anyways I just want to let people know what I have been through which is thousands of dollars, 4 clutches, 2 release bearings, my time and I would like to give people a little more education on the subject.

I know some guy is going to post on here about how great he has it and maybe even post his clutch pictures. Well after thousands of dollars, time wasted, 4 clutches, a couple of release bearings I am done with it. YES I had to pay this time, even though it is an obvious design flaw. Time to move on!!


Well now I have a new clutch, no issues, no problems

CoastalDav

My last truck had an NV5600. I replaced the stock clutch with SB Con O FE.
It was defective. Sounded like a train coming down the tracks. The seller made it good and sent another one. It was still loud, but I had a full pedal instead of a half pedal.

I'll never do another SB if I get another Standard Tranny.

I'm running a mush box now with a few additives. Doing OK so far.

johnh

iv'e heard that the dual mass clutches are problematic......the solution is a dual disc clutch



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.

shlen

johnh: The clutch that was problematic for me (in the pictures) was the S-Bend SDD3250, which I believe is a dual disc.

Oliverpuller

[Well now I have a new clutch, no issues, no problems[/QUOTE]

So what clutch did you put in?

dieselfreak21

Yes that is a picture of a DD clutch. Not a dual mass fly wheel. Dual Mass is the factory fly wheel and has the above mentioned problems.

Sucks S_bend didn't stand behind it. I had to have my clutch cover replace have only 60k mile and then find out I did't get the clutch I ordered. They aren't be all end all.

shlen

Oliverpuller: Once this clutch proves itself, I will tell you which one I am running. Then again maybe I won't, until a clutch company sponsors me. Why advertise their stuff for free? haha

SpeedyWS6

Well the old style clutch that ran metal on metal did not have near that gap. But people complained about the noise. I had one and it didn't bother me. But it sure made the truck hard to sell. From the looks of your pics I would want the old style if I were to ever run a dd again. I bet that thing sounded terrible once the pads fell out!

Rod_Montana

Because other forum members might need a clutch (like me) and do not want to go with South Bend.

If I don't get some good ideas in the next couple of months, screw it. Another LuK goes back in there.

Oliverpuller

Exactly... I will be pulling the trigger on a clutch possibly next week. I have been visiting this forum for four years plus seeking advise, recommendations etc. That is what this and all forums are for, to share knowledge. Oh well this post does not shy me away from a SouthBend clutch at all.

Fisherguy

I'm not saying I don't believe this story but I've never heard of anything like this before regarding any SB products. Makes me a little suspicious...
.... also I've never heard of any shop with a $175/hour shop rate.

My OFE has been a great clutch.

Oliverpuller

The OFE is what I am going to go with Fisherguy...

All I have is Intake/Exhaust mods and Smarty JR. occasionally towing 12000#

shlen

The pictures are worth a thousand words, can't make that up. I just wish I would have taken more pictures, especially with the other issues. Like I said, I am here to let people know what I went through. That is what forums are for. Maybe I just caught an exceptional line of just plain bad luck.

As for the shop rate...The bill that I saw...there is no where on it that says $175/hour. Somebody somewhere has exaggerated a bit. I have never heard or seen of $175/hour shop rate either.

Sorry to the other guys about not stating which clutch is now in my truck...just want to see if it proves itself, so I don't eat any words.

shlen

Do you like your LuK?

Reelay

I am having a clutch by South Bend installled the first of next month. They are installing a G56-OK. My current stock clutch has made it a long ways {over 100k} and just now starting to slip bad when pulling the trailer. I pull a 14K fifth wheel sometimes a little heavier. I am not a lead foot and always drive the truck as if it were my last one. I have heard nothing bad about those clutches but there is always one ot two built on a Monday. So will see how my works out.