Clutch Slipping????

[RandyW]

I have a 2018 3500 Dually 4X4 with a 6 speed manual transmission. It has 24,500 miles and yesterday while accelerating it felt like the clutch was slipping. I ease off the fuel and eased back into it and it seemed to slip again. I was only a mile from my destination, so I slowed down and made it to my destination without any issues. After about an hour I headed back and tried to get it to slip again, and it wouldn't even if I was in a high gear, slow speed and full throttle. It worked okay the rest of the way and then today it happened again. I really don't think it's the clutch, my last Ram had 221,000 with the original clutch so I'm well aware how to drive without unnecessary wear on the clutch. BTW my car is a 6 speed manual with 180,000 miles and no issues with the clutch. My son says his 2018 2500 with automatic does the same thing and he says he shuts the engine off and restarts and the problem goes away. Any ideas of what's going on????

 

[petersonj]

So, if you are in sixth gear and start getting into the throttle, are you saying that engine rpm increases, but road speed does not? If this is happening, then the clutch is slipping.

Assuming you still have the OEM clutch, it won't be slipping because of your driving habits. Your OEM truck is equipped with a dual mass flywheel and a self adjusting clutch. It will likely be slipping because the self adjuster built into the pressure plate is malfunctioning. Not the best design. Most people get rid of the dual mass flywheel and install a single mass flywheel and a NON self adjusting pressure plate. Like the old days - simple and very reliable.

What year was your last Ram? The dual mass flywheel and self adjusting clutch were introduced in the 2005.5 when the G56 transmission came into the picture.

- John

 

[RandyW]

So, if you are in sixth gear and start getting into the throttle, are you saying that engine rpm increases, but road speed does not? If this is happening, then the clutch is slipping.

Assuming you still have the OEM clutch, it won't be slipping because of your driving habits. Your OEM truck is equipped with a dual mass flywheel and a self adjusting clutch. It will likely be slipping because the self adjuster built into the pressure plate is malfunctioning. Not the best design. Most people get rid of the dual mass flywheel and install a single mass flywheel and a NON self adjusting pressure plate. Like the old days - simple and very reliable.

What year was your last Ram? The dual mass flywheel and self adjusting clutch were introduced in the 2005.5 when the G56 transmission came into the picture.

- John

I just can't believe my new truck already has clutch problems. :-( My other truck was a 1994 with the 5 speed. If anyone knows of a very reliable shop that can install a new clutch somewhere around the Dallas/Fort Worth area, please let me know. I live about a hour north of there and don't know of anyone around my area.

 

[petersonj]

I feel your pain. Many people have experienced this unexpected failure at low miles with the dual mass flywheel trucks.

I can't help you with a repair shop recommendation, but I can tell you that South Bend Clutch offers excellent choices for aftermarket single mass flywheels and non adjusting pressure plate clutch kits that will fit your application. I have installed a couple myself.

- John

 

[BigPapa]

Call SBC and tell them where you are. I guarantee they have an installer near you.

 

[GCroyle]

Does the pedal effort and engagement position feel the same as it was pre slipping?

If the clutch comes out a nice clear shot of the self entire length of the self adjusting spring (the smallish coil spring in the cover stamping) and a profile shot of the clutch while still installed on the flywheel might offer some info.

 

[AH64ID]

It sounds like a standard DMF failure, until you state that it mimics a 68RFE. Either something is wrong with both trucks, or something is lost in translation. The feeling of a slipping clutch isn’t something normal for a 68RFE, and certainly can’t be fixed by turning it off and on.

 

[RandyW]

Took my truck to the dealership today and they claimed they took the inspection plate off and there was nothing wrong with the DMF and they test drove it and couldn't get it to slip. They said even if it was going bad it's not covered under the warranty. Charged me $165 to tell me nothing is wrong. Not sure what to do next but I'm afraid to connect to my 41 ft fifth wheel and head out anywhere for fear I'll be stranded somewhere down the road. Any suggestions?

 

[AH64ID]

Tow the trailer around town and see. It likely won’t strand you if it slipping, but you may have to slow down.

If it does feel that way again pay close attention to the rpms vs speedometer, you can easily see a clutch slip with the tach.

 

[petersonj]

@RandyW , that dealer was of no help to you. This is not a dual mass flywheel problem. A failing DMF starts breaking down internally and becomes noisy and out of balance It does not slip. Yours is quiet and your clutch is likely slipping on occasion. The slipping clutch event is highly unlikely to happen during a test drive.

You likely have a self-adjusting clutch / pressure plate problem. The problem can and will probably be random and infrequent at first, then become more frequent and the clutch will start slipping with lesser engine load as time goes on.

You are probably okay to use the truck for awhile. You can prolong the clutch's life by quickly backing of the throttle when you feel a slippage occur. The issue is not likely to leave you stranded. You should have some time to schedule a repair - just don't wait too long.

In one of my earlier posts, I asked the following question to verify a slipping clutch scenario. You really didn't confirm this was or was not the case. If this is not the case, then everything I have posted does not apply:

So, if you are in sixth gear and start getting into the throttle, are you saying that engine rpm increases, but road speed does not? If this is happening, then the clutch is slipping.

- John

 

[RandyW]

John, sorry for not fulling answering your earlier question. Yes, the first time it happened I had just gotten into 6th gear when I noticed the RPMs were higher than normal, so I first thought that I hadn't shifted to 6th gear, so I pulled it out of gear and put it back in to make sure I was in 6th gear. When I gave it some throttle the RPMs would increase but the road speed didn't. I got off the throttle and slowing advanced the throttle just enough to maintain about 50mph for about a mile to my destination. The next time it happened I was taking off from a stop light and about the time I was getting into 3rd gear the RPMs increased but the speed wasn't picking up so I backed off the throttle and slowly got back on the throttle and it seemed okay. It hasn't happened since (maybe 100 more miles on it).

 

[petersonj]

Not sure what to do next

Go to a reputable truck transmission shop that repairs / replaces pickup truck transmission and clutches. Ask this question to the person in charge, "What can you tell me about dual mass flywheels and self-adjusting clutches in the Dodge Ram Cummins powered trucks?" I am sure that you will get an earful. Tell them your symptoms. I will bet they might even test drive your truck at no charge.

- John

 

[GCroyle]

Several good replies above.

The G56 DMF it can rattle and go out of balance at high mileage but it does not have an internal clutch. The 7.3L Ford DMF did have an internal clutch pack and it could slip under certain conditions.

RandyW ask the dealership to show you the inspection plate they removed.

The trans case completely covers the clutch and the eng to trans adaptor covers the entire engine side. The only access is the slave cyl port and the small holes for the barring tool and the DMF to flex plate bolt installation.

You're correct if you are towing, in 6th and accelerate the RPM cannot spike up it must stay sync'd to MPH increasing.

The one oh crap that can happen to the Self Adjusting Clutch (SAC) is if the SAC system does a forward adjust and thinks the disc is thin when it is still full thickness. That's why I asked for a pic of the SAC spring if the trans comes off. This unintentional forward adjust is rare but it also messes up pedal feel, engagement point and likely release.

Do you have a bore or snake camera? I don't remember if this has a chance or not put its real easy to pull the slave cyl off. and see if you can get a SAC spring into view and take a pic. The pic should focus on the spring position vs the finger that the spring and adj ring are located on. I'll look for a pic of same later.

And until this is resolved other factors cannot be ruled out. The hydraulic system can be inspected manually to feel for is it "relaxing and returning" and not maintaining a load on the bearing, and any source of contamination. The basic hyd system manual inspection is remove the slave cyl and by HAND push the pushrod all the way back in to the cyl. You will feel fluid being moved back to the reservoir, compressing the preload spring inside the slave cyl . If you need it I bet I can come up with a stroke distance to compress it fully.

Has anyone "topped off" the clutch master cyl reservoir lately?

Gary

 

[RandyW]

Gray, I'm not taking my truck back to this dealership for any reason. The service writer didn't have a clue what I was talking about, and I didn't have a "warm-fuzzy" feeling about leaving my truck with them. I don't have a snake camera to take a picture of it, but I will get under there tomorrow and see what I can see and then call SBC and ask them if they would recommend someone in my area that knows about this type of DMF.

 

[MConyers]

Been a while; but, seems like typically either you stay with a stock style DMF and clutch replacement or convert to a single mass flywheel and a new clutch and hydraulics. I went with a Scheid install of a Kenny's clutch on my 2011, only downside was the pedal was quite a bit heavier and the kevlar/ceramic combo made it a bit more fun to back up. Traded the '11 for a '16 and about put my foot through the floor, maybe exaggerating a bit, the first time I drove it.

One thing I recall, that I didn't see mentioned... The stock clutch on my '11 when it would start to slip in 6th gear with heavy throttle, the computer would cut power almost immediately. Don't recall having a case where the engine would rev out of sync with vehicle speed. I wasn't towing when the clutch slipped, if that makes a difference.

Edit to add, self adjusting clutch was added at some point ('16? maybe earlier) https://www.turbodieselregister.com/threads/g56-stock-self-adjusting-clutch.257097/

 

[nukegm]

randy w

2018 ram 2500. at 12k my clutch quit working. dealer repaired, after 31 days at dealer. had it a short while after that, all good. then clutch failed at 19k. dealer replaced flywheel and everything else. made it to around 50k, clutch failed again.so i replaced everything with southbend clutch single disc. new hydros. its great now. 73k all i can say is the dealer has inexperienced techs and the factory clutch is garbage. my 02 5.9 had 219k on it when i replaced that clutch. you will get more noise with dumping the junk dual mass flywheel. good luck. cheers!

 

[AH64ID]

randy w

2018 ram 2500. at 12k my clutch quit working. dealer repaired, after 31 days at dealer. had it a short while after that, all good. then clutch failed at 19k. dealer replaced flywheel and everything else. made it to around 50k, clutch failed again.so i replaced everything with southbend clutch single disc. new hydros. its great now. 73k all i can say is the dealer has inexperienced techs and the factory clutch is garbage. my 02 5.9 had 219k on it when i replaced that clutch. you will get more noise with dumping the junk dual mass flywheel. good luck. cheers!

It may not all be dealer techs, or even a junk clutch.. but rather the wrong clutch for the application. The 6.7 with its added displacement, VGT, and tuning is much harder on a clutch than any stock 5.9 and many modified ones. The 6.7 produces so much low rpm torque that the DMF fails.

My dads 06 went around 100K on the DMF with more power than a stock 6.7, but not as much low rpm torque.

 

[Flinty]

My clutch made it 66k. When we took it out the surface of the flywheel was obviously cooked. I experienced the same thing you did - slipping in 4th and 5th under load and the clutch would hook up intermittently. Work fine for a while, then zinggg, it would slip. I don't tow heavy in 6th unless I'm on a flat straight stretch. Replaced it with a SBC g56-ok-hd. New hydraulics and all. I'm at 88k with no problems. I use the DMF to hold down a tarp now. What an ill conceived design. It also made a weird noise from the day I bought it.

 

[NIsaacs]

but rather the wrong clutch for the application.

I think after 12 years of "the wrong clutch for the application" it is safe to call it junk. It has been documented from day one that it is failure prone. Even detuning the engine and derating the GCW, it still fails. Yet, year after year, Dodge/Ram continued to use it.

 

[GCroyle]

Is there a bit of confusion regarding the stock 6.7L torque in a G56 vs auto versions? DTR for 2018 lists 660 lb-ft for G56 and 990 lb-ft for the Aisin auto. The G56 early version G56 was 610 lb-ft for less than a 10% increase in its engine series life.

https://dieselresource.com/diesel-r...cummins-specifications-information-2010-2018/