Reverting from Single Mass Flywheel back to Stock Dual Mass Flywheel write up
 

Project Dual Mass

After two failed single mass flywheel implementations I reverted back to stock. Part of this was a failing clutch after 15k miles, and then after the extra noise, vibrations, and harder shifting that came with the second brand I decided I’d rather deal with the weaker Dual Mass. I also didn’t like suffering a 10-15% fuel efficiency reduction running a single mass flywheel. And finally- after running a single mass for 1 year, my input shaft was loose- and it had been tight prior. After paying for a transmission rebuild, I decided I’d rather stick to what this transmission was designed by its makers to run, and yanked out the single mass aftermarket to return to the dual mass.

Because the vast majority of other Single Mass Flywheel converters appear to be very happy with the aftermarket option, I could find little to no information online regarding reverting back to stock- so this write up is for the minority G56 owner, but hopefully will save someone a lot of the time I spent tracking down parts and trying to figure out exactly what I needed to do.

Here’s what you need:

1. LuK part number 05-182 or 18739-07124037 clutch and flywheel kit.
2. You will also need to revert back to stock hydraulics. I chose the Valeo 5291116 kit.

If your stock stuff was thrown away while installing the single mass aftermarket clutch you will also need the following Mopar parts:
(1) 52104720AE plate
(1) 4798968 plate
(8) 5085962AA bolts (goes through above plates into crankshaft) Spec. M12x1.25x18.00
(8) 6508033AA bolts (goes through above plates into flywheel) Spec. M10x1.5x25.00
(8) 6036096AA bolts (pressure plate to flywheel) Spec. .312-18x0.98

There is lots of info on pulling the transmission so I won’t get too detailed here. The basic order in which I did things was as follows- I recommend you consult your repair manual or find a good walk through with pictures on a model close to yours- I ended up consulting several, and none were spot on to my truck:

1. Put the transmission in neutral
2. Remove console/cup holders
3. Remove the shift tower (4 E12 bolts- you need an E12 socket)
4. Under the truck, remove the backup light switch, and 4x4 selector (mine’s an electrical connection- you may have actual linkage here)
5. Drop the skid plate under the transmission/transfer case on the driver’s side if applicable
6. Drop the front and rear drive shafts
7. Place a transmission jack under the transmission
8. Remove the transmission mount nuts from the bolts
9. Remove the cross member
10. Remove the slave cylinder and set aside
11. CHAIN OR STRAP DOWN THE TRANSMISSION – I was working on a lift, with a lift jack, and was fine with a few ratcheting tied downs (I like them better than chains).
Attachment 51893
12. Remove the bell housing bolts and pull the transmission back
13. Remove the pressure plate and clutch disc
14. Remove the old flywheel.

Now you get to put the dual mass back together. (And now is a great time to check your rear main seal and cam seal for leakage)

The parts go in as follows:

1. The larger of the two adapter plates goes against the crank. One side has a ring that slides over the crank, the other side is smooth. The smaller plate is second, and is pressed against the smooth side of the larger plate. Then use the M12 bolts to attach it to the crank, and torque. The specs I found called for 110 ft/lbs, so that’s what I did. See the image- I use a grease pen after each bolt is torqued to mark that it’s done. I use a star pattern to apply even torque, as most others do. Please note in the picture that I was test fitting the flywheel bolts- I couldn’t get them in time from a dealer so I bought spec bolts and wanted to be sure the heads would not contact the adapter on the block- if you do the same, you need a nut for each bolt so you can put them in the adapter plate and tighten them into place (not torqued though) and turn the motor to make sure everything clears, then remove the nuts and bolts for flywheel installation.

2. Align an adapter plate bolt hole with the window for accessing these bolts, and remove the cover over the window: it is held in place with two 10mm bolts- the bottom one comes out, the top one only needs to be loosened as the cover slips off it. (It’s the window in the orange diamond in the photo).

This is how it should look:

Attachment 51894

3. To make installing the flywheel easier, I used a grease pen to mark the flywheel where the bolt holes are. See the white triangle in the photo below. That enabled me know about where to line up the flywheel while holding it up to adapter plate. This can be a struggle- you’ll need a little patience most likely, and a buddy holding the flywheel that can move that heavy monster in small increments to align the first bolts. Only get the bolts hand tight to start- you have 8 holes that need to line up and that’s much easier if they are a bit loose.

4. Once the flywheel is held on by a few bolts, you can install one of the bell housing bolts about half way to use as a leverage point for turning the whole package in order to go through and snug down all the bolts. The torque spec I found was 55 ft/lbs, but my Snap-On torque wrench wouldn’t fit due to the casting around the window- so I went with the old German spec- gudentite. See the Red Square in the photo below for the bell housing bolt placement- use a flat bladed screwdriver and put the slotted end into the flywheel teeth- use the bolt for leverage and *gently* turn the assembly to line up your grease marks with the window (see the greenish/yellow oval). I know some will say don’t do this- but if a cheap flat bladed screwdriver messes up your flywheel teeth on a Cummins- you got a crappy flywheel- take it back and get a better one, or stop taking steroids. Really though- the key here is go two teeth at a time, patiently and don’t try for too much turn at once and it will go smooth. Also note that in the yellow circle you see the bell-housing bolt hole (yellow arrow on it), I found that to be handy as a visual point to line my grease marks up with to get the bolts in.

Attachment 51895

5. Use a little brake cleaner to clean the friction surface of your flywheel and pressure plate. Friction surfaces do not like dirt, grease or skin oils.

6. Install the clutch disc and pressure plate with the supplied clutch alignment tool and torque your pressure plate bolts – the spec I found was 30 ft/lbs.

7. Now you need to change your throughout bearing because you are in here, and you might as well (it came with the LuK kit). Just pull the clip on the left side pivot ball on the clutch fork and it will all slide off the shaft. It should be reasonable to figure out how to take the bearing off the fork and put the new one on- it’s two clips (and the new bearing comes with the clips).

8. The LuK kit comes with a small tube of grease- or you can use your own, but put a light film of grease on the face of the throughout bearing and the input shaft.

This is what it looks like together:
Attachment 51896

9. It’s time to put everything back- carefully push the transmission back into place, re-aligning the input shaft into the clutch/flywheel assembly and bolt every back up with the exception of the slave cylinder.

10. This is the reverse of the above procedures.

SLAVE CYLINDER INSTALLATION.

Your stock Dual Mass Flywheel doesn’t need the beefier SMF hydraulics. So climb under the pedals and you’ll see the connecting rod attached to your clutch pedal, going through the firewall to the master cylinder. You need to remove that rode from the pedal, pull the red clip and separate the clutch safety switch, and then remove the two nuts from the master cylinder so it can be removed.

On the firewall in the engine compartment you’ll probably see a white fluid reservoir attached to your firewall very close to the driver’s side fender- you need to remove that and then pull the assembly out from the top (be sure nothing is zip tied to anything underneath first).
Move over the safety switch to your new stock master cylinder, and reinstall into the firewall, and then reinstall the slave cylinder into the transmission.

Congratulations- you have now gone back to a stock Dual Mass Flywheel- enjoy the quiet, smooth, and more fuel efficient operation of your Ram.

Great write up!! [guitar]


my only question is how does going to a single mass flywheel drop your mileage by 12% to 15%?? I have never heard this before.

Excellent write up. My mileage remains mediocre and I can't say it's changed any since converting. Back to the silent G-56 we remember?
Thank you.

Two things: shift points, and balance.

With a single mass flywheel you have to run higher RPMs or let your transmission take the torsional vibration abuse the dual mass had dampened. Higher RPMs mean more fuel consumed.

The dampening effect of a dual mass smooths out power, balancing the drive-line, and allowing for more of the power to be used at lower RPMs.

More power at lower RPMs = increased fuel economy.

Most drivers running a SMF have other mods, and are producing far more power than stock. They were slipping the clutch or destroying the dual mass in the factory setup, effectively wasting fuel. They likely already shift above 2,000 rpm and don't use lower RPMs at all. Thus they may actually see an increase from a more powerful clutch setup as it eliminates the wasted fuel from clutch slippage, or they see no difference, or a negligible difference because they only use the higher RPMs to begin with.

That's why nobody in the Ram world has noticed this - it applies to very few Ram owners.

I'm 400 miles in since reverting back and I am LOVING MY TRUCK AGAIN!

The truck is so quiet, so smooth and so nice to drive I am just beside myself. I don't have a full tank of gas through on the dual mass to see what my final fuel mileage will be but the mixed tank (partial single mass operation, partial dual mass) was up just shy of 10%- I went from 17mpg to 18.5mpg. More than anything though, I love having back the silent transmission, easy shifting, and far more smooth operation.

I believe SBC or Valair could clean up producing a dmf a bit stronger than the stocker for the stock/moderate hp+ guys.

Jona Gold,

In another thread, you mention that your 1st aftermarket clutch was a Southbend that failed in 15k miles. Then your 2nd aftermarket clutch was a Valair that you replaced because of the noisy gear rollover it caused.

Do you have more details on these clutches? Were they single or dual discs? What exact clutches were they?

First was the South Bend OFEK, single disc, single mass. Second was a Valair 400hp single disc, single mass kit. The hydraulics from the South Bend had been re-used with the Valair- otherwise everything was swapped.

The South Bend was pulled due to weird pedal vibrations and once out, we could see that one side (pressure plate side) was toast, the other side fine.

The Valair was pulled because of a funny idle vibration that got worse between 1500-1700rpm, then smoothed out, and noise, including a bark-like sound on take off from a stop, and shifting from 3rd to 4th. The bark was intermittent at first, then gradually got worse. The gear noise was terrible and worth the change by itself, but the vibration and bark concerned me the most. I originally replaced my damper with a 6.7L to try to address the funny vibration after the Valair was installed, which helped, but it did not eliminate it.

JG,
Are you running stock power?

No. I was running an AFE intake with pro guard 7, AFE turbo back exhaust, and the Edge Juice w/ Attitude monitor. I ran the edge mostly on 1 for fuel economy- a modest add to power, but I use 2 (the tow setting) for towing. Before all this trouble I'd run stage 3 (drive) if I was in the mood for more power and cared less about fuel efficiency. After installing the first clutch, I also added the FTE resonator to kill cab noises- the drone was awful from the AFE exhaust. Then my AFE intake literally came apart- the rubber is complete crap quality, so I'm back to my factory box with the deep Wix air filter. Now that I'm back to the dual mass, stage 3 will be used sparingly, for passing only.

I did the conversion @ 37K when my rear main was seeping. The installer said the dmf was like new but urged chucking it.
I had run Smarty on #1 or #3,34" tires and 2000# on my back. Stock torque management helped I'm sure.

I only went with the SMF setup because my installer strongly recommended it as well. It cost more than just fixing what was broke- but I was sold on how much "better" and more "reliable" it is. My experience was obviously opposite that. I had to do the conversion "backwards" myself because like most people, the installer's opinion of a dmf was that they are junk.

He drove my truck late last week- about 500 miles into my having the DMF back on couldn't believe how smooth, and quiet my truck is. He has another customer with an identical truck to mine who is running a Valair dual disc setup that the owner hates- so the installer is going to recommend he go back to the DMF setup as well.

Wow, you have a power adder but you still installed the DMF clutch...

Of course the OEM DMF clutch is quieter but it's still unreliable with a short life span.
How often and how much are you towing? Do you have an exhaust brake?
An exhaust brake is hard on the clutch, especially the weak DMF clutch.

It's unusual that you had issues with both the Southbend clutch and the Valair clutches. Both companies make excellent products.

The SB OFE clutch was perhaps a bit too much clutch for how you use your truck. I wonder if the SB single heavy duty organic would have been a better choice.
Then I would have recommended thicker trans fluid to reduce the transmission noise.

Regardless, I wish you well with your truck.

Stealth- I use my truck to haul about 12-15k twice a year, and then occasionally tow a car hauler with a lightweight car. As noted above, my circumstances apply to the minority of Ram owners I think. I also value the refinement over added power. In stock form, my Ram would perform fine for my needs.

I have no exhaust brake- which certainly factors into the longevity of my original DMF. Given the many posts this spring about aftermarket clutches falling short of lasting 100K, I'd say my DMF was just as reliable, in fact more so in my experience with single mass setups- even if I was just horribly unlucky.

Here's what Peter had to say about the recent string of South Bend failures on another post on this site: "Funny thing is we had one of the worst winters in decades and have seen a lot of this this year but everyone keeps insisting nothing happened. Our OFE series clutch has held up well through time but obviously did not do well for you."

Here's a link to the post: https://www.dieseltruckresource.com/...ghlight=clutch

Personally I'm just at the point where I'd rather have the nice quiet smooth engagement and pay $500 for parts rather than $1000 when they break if neither is going to last much longer than the other. But I don't tow heavy often, or use lots of mods to produce more power.

This thread was started for the minority who want to go back to a DMF- not to try to convince anyone else that's what best. I prefer people think for themselves. However, I have made other posts that I do feel the DMF is best, given my experience. I think it's important for people, when making a decision like that, to have both sides. When I made the first swap, I was all in for a single mass- it was the cat's pajamas of clutches. Then after investing thousands, I was not only out a lot of money, but I was no longer as happy with my truck. Since I've started down this road though- I've found I'm not the only one, just one of very few people who have decided stock is better (for my application) to bother posting on internet forums.

I have another thread in the performance section on all the things I did to quiet down my single mass (with no mention of reverting) for those that love their single mass but are hoping to quiet it down. Which by the way- couple all those things with the factory DMF and my cab noise rivals my wife's Cadillac. If I could just find magical suspension for my truck now.....[laugh]

Thanks for the info.

While I have a NV5600 6 speed manual instead of the G56, I do have a aftermarket Southbend clutch (old style double disc 3250) that drives me nuts at times.
Mine is the early style dual disc that rattles when the clutch is pushed to the floor and causes some gear rollover when the trans is hot.

However, I have not had an issue with it for over 4 years. Towing our 10k lbs 5th wheel all over the B.C. mountains.
I tow detuned to about 450RWHP/900RWTQ with a BD exhaust brake.

When my trans and clutch get tiring, I just have to read some threads on automatic transmissions. Then I feel much better!! :)