Working drivability issues on 2011 2500 w/manual trans

[AH64ID]

Good tracking of your mods. Did you dyno with just the Banks intake? Those gains seem high for stock tuning considering the flow of the stock filter.

I have 3 friends that went with dual disc clutches, every time I hear them idle I am glad I went single. They hold great, but as you noted they are surprisingly loud and don't allow any low rpm operation in upper gears with a load.

Do you thing the gear oil was cleaning or wearing the syncro's? The manufacturer recommended fill is not ATF, but a GL4 style fluid (IIRC it is delvac 50).

 

[schmalda]

AH64ID,

I baselined the truck then only changed the intake and realized a 2% increase in hp after averaging 5 runs on the Dyno function of my datalogger. I also recorded an 0.4 psi increase in boost pressure during the same test.

Regarding the trans fluid...I'm tracking the Benz recommended Delvac 50 but went back to Mopar ATF4 because the syncro performance seemed to improve and suspended synco material reduced w/the ATF. I don't know what the syncro cone design looks like on this trans but I reasoned that the GL was providing too much hydrodynamic action and reduced spooling.

David

 

[AH64ID]

Interesting on the data logger, is it calculating hp based on fuel burn or 0-60 runs?

 

[schmalda]

The datalogger uses your vehicle weight (I input my book value + my weight + est fuel weight + my stowed items), a calibration function to determine your actual final drive gear ratio depending on the gear you pick for run and a drag function which measures how fast your vehicle decelerates in neutral to determine your drag coefficient. After these inputs are made you make a rolling start run; I use 4th gear and start around 1000 rpm, you push a start button on the datalogger then when it sees a perscribed speed increase it starts logging. I run the motor up to 3200 rpm and let off, when the logger sees the deceleration it stops logging and provides a hp & torque curve based on your vehicle speed and time history.

 

[AH64ID]

Very interesting, sounds like a complex logger.

The OEM filter is good for 450+ rwhp, which is why I am surprised you saw any gain.

 

[jhenderson]

Nice explaination of your mods, but I disagree with your assessment of trans trouble. I strongly doubt Penn synchromesh damaged your trans. It's the recommended fluid for the NV5600, which uses the same syncro material as the G56. Also realize that Mercedes ( the trans mfg) recommends Mobil Delvac 50 trans fluid, which is even higher in viscosity that the Penn synchromesh. I am sure the slow shifting is caused by the dual disc. That trait, along with the noise has be discussed many times on this site.

 

[schmalda]

Jhenderson,
You may be right. I did a lot of fooling around to try to find the right adjustment for the clutch but it seemed I always ended up with a little drag when clutched in.

Sounds like you know something about this trany…I had a question buried in my update that maybe you know about. When parking if I back down hill in to a parking spot in reverse or pull down into a parking spot in 1st and I leave the transmission in that gear and then the truck is shut off using the engine to hold the truck parked without setting the parking brake I can not get the transmission out of gear unless I start the engine…ever tried or heard of this?

 

[RVTRKN]

I bought and used the MB Mobil delvac 50 and put about a thousand miles on it, and I saw the gold flakes glittering in the sun. I drained the oil and filled it with Pennzoil synchromesh and drove it for a couple of hundred miles just to see if the trans would run cooler with the thinner weight. Then I contacted CKelley1 and confirmed the mix he uses in his fleet of G56's pulling 40K GCVW on a regular basis. And so far I'm happy with it, but I haven't taken a sample of it yet to see if I can see the glitter. I'm not too worried about CKelley1's mix because it has been proven in his fleet, but what I like the most about it is its synthetic and as hot as I've seen the trans get thats a plus. I have an app that I can see torque and HP and can data log as well but there is no calculation as mentioned above, the app is called Dash Command and has a lot more capability then just seeing HP and TQ. Here are a couple of pics of it. I have the ability to see it on my Nav screen, the other abilities allows me to see my sensor modules.

 

[NIsaacs]

Jhenderson,
You may be right. I did a lot of fooling around to try to find the right adjustment for the clutch but it seemed I always ended up with a little drag when clutched in.

Sounds like you know something about this trany…I had a question buried in my update that maybe you know about. When parking if I back down hill in to a parking spot in reverse or pull down into a parking spot in 1st and I leave the transmission in that gear and then the truck is shut off using the engine to hold the truck parked without setting the parking brake I can not get the transmission out of gear unless I start the engine…ever tried or heard of this?

The only thing that can cause this is one or both clutch disks are not releasing. I would guess that under torque parked, the inner disk is still holding, that the center plate under torque is not releasing. That without the engine running to jiggle it loose it stays clamped.

Nick

 

[AH64ID]

It's the recommended fluid for the NV5600, which uses the same syncro material as the G56.

I am not sure I believe that. The MB spec 235.13 is a GL-4 based gear lune which is not compatible with a NV5600's syncro's.

The MB specs are closer to what a NV4500 wants, and we all know that NV4500's and NV5600's must use different fluid, mainly for the syncro materiel.