LUK Clutch Kit with Cerametallic Disk

Five months ago clutch went out and it was replaced with a LUK clutch set with a cerametallic disc fly wheel. Put about 4500 miles on truck, unloaded with no issues. Recently took two trips with my RV – pin weight 1600 lbs. No issues starting in 1 st gear as long as I was on a level surface. Starting on any incline, however slight, the shudder was so violent you would have thought you were going over speed bumps. Shudder ceased as soon as I could get up to 15 mph and shift into 3 rd gear.

Actions to date: Contacted LUK support, if you can call it that. They said center bearing or possible broken spring during installation.

Center bearing replaced – no change, Drive shaft sent to shop that specializes in rebuild, new u-joints and drive shaft re-balanced – no change. Next week truck goes into dodge to check drive shaft alignment per TSB 03-003-04. If that checks out OK, here is the question.

The clutch set is going to get pulled and inspected – would you stay with the cerametallic disc? Would you stay with LUK?

2003 ram turbo diesel 5.9, 2 WD. single rear wheels, 6 sp with 126 K miles

 

Thanks for the TSB. I use a different clutch and love it, but, have the torque launch shudder in reverse. I had the driveshaft rebuilt as the center bearing rubber was toast. It's since returned and on other HD pickups I have used poly center bearings that are stiffer than rubber. You would have to put a plate under the bearing to support using the GM design on a Dodge as they don't have a specific Dodge part, but, many Dodge owners run the GM part with good results. We have watched the driveshaft hop up and down while doing a brake stand to simulate the problem on a couple Chevy auto 2500's. The Poly bearing stopped it. A Camera mounted under the truck can help narrow the problem down.

The other problem you could have is spring wrap where ladder bars may help.

Regardless when they check the drive line angles make sure your RV is on it. At the end of the day it's all about compromising the angles between loaded and unloaded so another solution may be airbags to level the truck back out when you put the RV on it.

Is your clutch smooth otherwise? IMO it's not your clutch and the best way to prove it is when you take your foot off the clutch pedal: is it still hopping? Yes: it's not the clutch.

BTW a 4 door long bed like mine is too long for a 1 piece driveshaft.

 

LuK has been OE supplier since the NV4500 trans hit the market and all 5.9L and 6.7L clutches have used a fiberglass based friction material, not buttons. WE owners have driven the addition of higher capacity HD etc clutches and the suppliers heard and responded. The first choices have been increased clampload, higher coeffiecent of friction facings (buttons) and really strong torsion dampers. These address the I WANT A STRONGER clutch demand pretty well.

Now we see your truck and conditions.

2WD
Trailer weight ? but pin is 1600# now add the stuff in the bed (assumed) 1600#+++
INCLINE!!!!!!!!!
Button facings.

This is a very tough scenario for a button disc system to respond smoothly to as it wants to hook and go or be released.

Last month this scenario happened to me.

2WD
10,000 trailer with over 1,000 toungue weight, a bed full of stuff including firewood.
7 degree (12% slope) yes, I measured with I phone level, on gravel in a tight turn around access to my site.
Fiberglass facings.

I dreaded this scene as I made my first of 3-4 approaches because I couldn't see the site, it was all covered with leaves just like the rest of the area.

I carefully controlled the friction zone, ran at VERY low engine RPM trying really hard to minimize that slippage time but its unavoidable, the clutch has to take it.

The organic facings did the job without any chatter or even tire slippage on the gravel slope.

I don't know if I could have driven your truck better than you, but I'm doubting it. IMHO this trans should have been built with much lower 1st and REV ratios to make these situations easier.

Suggestions, you always need to launch in 1st at IDLE no matter what, loaded or empty. Buttons DO NOT like to be slipped they are successful in big rigs due to their low low ratios at launch and maneuvering.

Another item on your truck that you really should add to the checklist is the motor and trans mounts, if cracked they are not controlling the powertrain.

And welcome to TDR

Gary

 

JD thanks for the reply, very informative. And yes, with the clutch pedal released the hopping continues until I can get it up to 3 rd gear, abt 15 mph. I am holding off on drive shaft allignment as I have decided to order new shocks from Genos. Will wait for those to be installed. In trying to solve this issue, no one has been able to explain why this shudder only happens on an incline and why the shudder was not present with the stock clutch on an incline.
Again, thanks for the info.

 

I guess my comments didn't count.

Good bye.

 

Gary,
As this person is new to the forum I doubt he has any idea of your experience or background with a major clutch manufacturer. Perhaps they are still trying to apply and think about your comment and will reply later?

Regardless you did make a good point and I will be checking from broken engine mounts regardless if they are newer. My issue is an annoyance where the OP has a real problem. IMO it's the only downside to not having 4x4 low for backing the 5er up. - doesn't apply to the OP's problem.

I enjoy reading your informative posts. Yeah, we take for granted the selection of clutches available today that you pointed out the reasons they are available. - Thank You!

It would be interesting to know if one's foot is off the clutch if (clutch) damper springs problems etc. could still allow this shudder?

 

I had a ceramic disc in my 02. I hated it from day 1. Towing only made things worse. In today's market there are plenty of alternatives to ceramic that provide plenty of holding power without the harsh side effects. Ceramic is cheap, but sometimes cheap isn't worth what you pay for it.

 

I believe the ceramic disk is the problem.

 

I tried the LuK cerametalllic clutch some years ago and found that it wore into the flywheel relatively quickly and even worse, unevenly going around the circle. It also began to shudder considerably afterwards. Peter at South Bend Clutch provided my fix for the problem with his clutch.

 

Have you checked into that? my 04 is a 4door long box with a once piece shaft....

 

Yeah, no transfer case on my 2WD. The length of the transfer case makes the difference in being able to run a 1 piece according to a couple shops that build new driveshafts.

 

My bad didn’t realize it was 2wd.

 

My SBC OKHD has held a EFI 60hp tune under full throttle from a stop. 1800# camper and 35's.
On the freeway I have fun with the 130hp tune. No issues but I don't push it.

 

Update: But first I would like to offer an apology to GCroyle for not acknowledging his input to my original post. Your input was informative, but I did not know how to respond to it. I never heard of “Button Systems” and I was not sure what the friction zone was – I should have asked you to clarify.

I spent most of my free time last week researching clutch systems and now know what a Button System is and I am pretty clear on the Friction Zone, and I did take your suggestion and had the motor mounts and transmission mounts checked. Those plus the rear suspension checked out fine.

The source of the problem may be that the clutch was not properly broken in. I was referred to a specialty shop that works primarily only on diesel pickup trucks.

When we discussed the issue his first question was how many miles did you put on the truck to break in the clutch system? I did not know you needed to break in the system and the shop that installed the new clutch never mentioned a break-in process.

I had less than 300 miles – mostly highway before I hooked up an 11,000 pound trailer for a three day trip. I now know what the proper break-in procedure is as well.

He stated he would never have put this clutch in this truck knowing the load it was going to pull. He has the truck now and a trailer he will use to try and duplicate the problem. He indicated he will not suggest removing the clutch unless he is certain the clutch is the problem.

If that happens he is recommending a VALAIR Clutch # QNV56DDSN-ORG

Apologize for the lengthy post – If the old clutch gets pulled and shows signs of what happens if not broken in properly, I will upload pictures so others may learn from my mistake

Thanks to all for your input

 

That's a dual disc clutch rated for 550 HP. You turned the power of your truck up? If not it may be a bad idea to get too much clutch. Dual Disk has some downsides. My NV 5600 I found additional weight of HD clutch disc made the worn syncros feel notchier on my trans - I had it rebuilt.

I suggest calling South Bend Clutch at 574-256-5064 for advice. I didn't say buy from them, but, they can give you some ideas about clutches and even your problem. I am not knocking your shop, but, it's expensive to swap clutches out esp. when the shop misses a dowel pin and ruins a new clutch...

 

Contacted SB on Thursday and was able to speak with Peter. He has dealt with this issue before. Gave me a good explanation as to what was happening and was pretty sure the shudder I was experiencing was tire bounce. When I told him I wanted to purchase one of his clutches to replace this one he suggested that before I go that route I look at installing traction bars. And he did clarify that the traction bars would not eliminate the problem altogether, but would make driving the truck with a load on an incline eaiser to handle. Peter recommend Longhorn Fab Shop, checked with them and their traction bars for my truck are $972. Checked several places on-line but the quality just does not seem to be up to par with Longhorn. Big decision, tractiion bars - or new SB clutch for about the same price.

 

Glacier Diesle Ladder bars are certainly up to snuff in fit, finish and function and over a buck less then that right now--

https://www.glacierdieselpower.com/i-1170-03-12-bolt-on-double-x-ladder-bars.html

 

Thanks, I will check them out.