Clutch Slipping????

[AH64ID]

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/

No confusion, The G56 trucks never saw much of a power bump from 05 thru 18. The HO’s on the other hand made it up to 385/930 before the G56 was discontinued.

That chart does have an error thou, 930 lb/Ft was only available in 2018. 16/17 had 900 lb/Ft on the HO’s.

The extreme power delta is why I bought an auto over the manual with my 18.

 

[sag2]

The stock DMF clutch is self adjusting and does not like to be lugged. For some reason lugging it from a stop (perhaps it shakes) causes the self adjuster to adjust when it doesn't need to. Unfortunately the clutch has to be removed to reset the self adjuster. The procedure has been in the service manual for as long as I can recall DMF's.
#ad

 

[GCroyle]

sag2,

That shot shows the SAC spring and its position in pic is NEW disc thickness, thin disc thickness the slider and spring are near the end of the finger. New disc thickness and SAC showing worn position are not a match = problem.

Good image to illustrate with. Resetting can be done, but a bit of finesse and skill required.

Gary

 

[Ozymandias]

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

Still waiting for an answer to this question.

 

[MGreer]

Reply #11

 

[petersonj]

Still waiting for an answer to this question.

Reply #11 definitely confirms that the clutch is slipping.

- John

 

[Ozymandias]

Thanks, sorry, I over read this answer. Definitely slipping then.

 

[GCroyle]

Any update?

 

[Regcabguy]

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.

It's simply for sound dampening and does a great job. The aluminum case warranted it or no one would have bought one. I have an SBC single disk clutch and Amsoil MTG 75-90 fluid. It shifts very well and the fluid does a decent job of quieting down the trans. The trans does tell you immediately at low speeds that you are lugging it. I change out the fluid every 30K and it's like new. The magnet on the drain plug has a very light coating of fine metal. I've used it for 80K now.

 

[RandyW]

Okay, it's been some time and I still don't have an answer for my truck's clutch slipping. It's been okay for a while, even pulling my 16K# RV up a steep hill at 60mph, but then just the other day it started slipping pulling an empty 12 ft aluminum trailer for just a few miles and then has been doing okay again. Been to two dealerships and nothing. Contacted RAM and they were absolutely zero help. Seriously considering trading it for a Ford, but, before I go that route, I would like everyone's opinion on a couple of RAM options.
First, it's my understanding that they don't offer a manual shift truck anymore so IF I trade my truck for a new one which engine/transmission should I go for?
8 Speed, 6 speed or the Aisin transmission? Hemi, Turbo or the HO Turbo? Thanks for your advice!!!

 

[AH64ID]

Why don’t you just put a better clutch in it?

 

[RandyW]

Why don’t you just put a better clutch in it?

I attempted that also, I talked with a well know transmission shop in Fort Worth. He explained it will be harder to depress the clutch pedal and would have a "roar" at idle speeds. I asked about a time frame he could get to it, and he said he would contact me later in the week with a date to bring it in. I waited until the following week and no call back so I called them, and the guy was rude and said, "I told you I would give you a call when I can get to it" and with that, I haven't heard from him in over a month now.

 

[AH64ID]

I attempted that also, I talked with a well know transmission shop in Fort Worth. He explained it will be harder to depress the clutch pedal and would have a "roar" at idle speeds. I asked about a time frame he could get to it, and he said he would contact me later in the week with a date to bring it in. I waited until the following week and no call back so I called them, and the guy was rude and said, "I told you I would give you a call when I can get to it" and with that, I haven't heard from him in over a month now.

Surly there is another shop around?? SBC lists 6 distributors in the Ft. Worth area.

https://www.southbendclutch.com/dealers/

The aftermarket clutches do generally have more pedal feel, but if you stick to something like the OHD from Southbend it’s not bad and very driveable. The OHD we put in my dads 06 with a G56 was one of the nicest clutches I’ve driven in a HD truck. I preferred that pedal feel to then stock G56 clutch feel.

 

[petersonj]

I second what @AH64ID says regarding an OHD Southbend clutch with a single mass flywheel. It will be good for at least 200,000 miles.

If you stay with the OEM dual mass flywheel and the OEM self-adjusting clutch, you will likely have a problem with one or the other, or both before you reach 100,000 miles.

- John

 

[BigPapa]

Is there any chance you’re slipping the tires instead of the clutch slipping?

 

[RandyW]

Is there any chance you’re slipping the tires instead of the clutch slipping?

No, after owning muscle cars for many years and heavy duty trucks the last several years, I know the difference between a clutch slipping and the tires slipping. LOL

 

[AH64ID]

Is there any chance you’re slipping the tires instead of the clutch slipping?

Very doubtful, it’s not easy to spin the tires on the 3rd and 4th Gen suspensions… and that’s without the OEM torque management.

The modern trucks certainly have the power for a good burnout, but they also have several things that put that power to the ground without the ability to easily spin tires.

 

[BigPapa]

Just a thought. My ‘98 could break the tires loose under hard acceleration when I’d lock the torque converter or towing heavy without a lot of tongue weight.

 

[AH64ID]

Just a thought. My ‘98 could break the tires loose under hard acceleration when I’d lock the torque converter or towing heavy without a lot of tongue weight.

2nd gens seem much more prone to breaking the tires loose with lower power than the 3rd and 4th gens are.

 

[GCroyle]

RandyW

If I needed a dually and was nearby I buy that truck at your loss (it does have a wacky clutch) and grin all the way home and fix whatever clutch problem it has.

OK smart head comment over.

Pretty sure 2018 was the LAST year for the G56 handshaker, its a keeper. That trans needs to come out and see what's going on. And pics of the clutch in particular the springs in the Self Adjusting feature. sag2 posted a clip from the FSM of it in post 22 and that's where I'd focus. As far as a new system how it feels depends a lot on what system is chosen. You can go to a non aggressive non SAC system and the pedal feel will be like an NV5600. You can install a SAC system and have a light pedal feel and enjoy the clutch. Now this is about as close to an ad as I think I've ever come but the company I USED to work for built their own series of SAC's and for the G56 they packed in more clamp load and beefed its adjustment system. I installed one for a friend in his 6.7L dually 2008? and he's ran that truck respectfully hard towing a 34' Airstream for YEARS and no issues.

Until the trans comes off, or in the unlikely event that the hydro's are doing something completely wacky well we just don't have the hard evidence.

Gary