2007 dodge CTD with a G56, when i let off the trottle with the exhaust brake on there is a loud grinding noise like a gear sliping coggs and the driveline disengages. i can rev the motor and the grinding gets louder but no acceleration, after i let the truck slow down the grinding stops and all is normal. any ideas of what the problems is clutch? trans? or transfer?

 

I don’t know man, but you better get that thing to the dealer and have them look at it. I assume your still under warranty. Does it matter which gear you are in?

 

This is the first I've heard of something like this. Let's try and diagnose it.

1. Does this grinding sound happen on decel with the EB off?
2. You mention the driveline disengaging. This is all happening with the clutch pedal NOT depressed and on decel?
3. Are there any vibrations though the shifter either at idle or while rowing through the gears?
4. Have you taken a look under the truck to see if there are any fluid leaks from the diff, transfer case, or transmission?
5. Does it only do it in a certain gear or any gear?
6. How many miles on the truck?
7. Do you tow heavy?
8. Any mods to the truck, performance-wise (including DPF/EGR deletes)?

If you can answer these questions, we might be able to figure out at least WHAT component is causing the issue.

 

1. Does this grinding sound happen on decel with the EB off?

No not yet.

2. You mention the driveline disengaging. This is all happening with the clutch pedal NOT depressed and on decel?

the clutch is engaged and foot off the pedal.

3. Are there any vibrations though the shifter either at idle or while rowing through the gears?

Vibration in driveline between 40 and 60 miles per hour like unbalanced rotation.

4. Have you taken a look under the truck to see if there are any fluid leaks from the diff, transfer case, or transmission?

Yes, no leaks.
5. Does it only do it in a certain gear or any gear? 5th and 6th gear only
6. How many miles on the truck? 58000
7. Do you tow heavy? 15,000 max
8. Any mods to the truck, performance-wise (including DPF/EGR deletes)? Only a lift kit and and bigger tires. nothing else.

 

Sounds to me like you've spun a weight off your flywheel. These G56's have a dual mass flywheel that is intended to dampen the transmission noises. The G56 is an excellent transmission but is noisy by nature so Chrysler in their infinite wisdom didn't want to offend the bankers and lawyer's ears with a noisy transmission and put a dual mass flywheel on it. It is the weak link of the entire drivetrain, if you ask me. I would give Dan at ValAir a call and get a price on a replacement clutch with a standard flywheel, unless you want to upgrade to a stiffer single disc or dual disc while you are in there. You will also need the heavy duty hydraulics if you upgrade the clutch, so make sure you get that when you buy the clutch kit.

 

I will give that a try even if its not the problem i will have a good clutch that will handle the power from chips to come.

thanks for your help

 

my tranny started giving me problems at 10k had the ebrake on it they changed the fluid to try and fix it didnt work replaced it 5 months later at 50k. in my opinion after talking to some techs and other people since these run a tranny fluid instead of gear oil, that it wears out faster especially if you tow a lot and run a e brake but thats my opinion . i change my fluid every 4 months or 30k just to be safe

 

gear oil in a G56 will kill it quick!!

 

Not the flywheel or the clutch , change out with dual disk and new flywheel still have the same problem out of the transmission. Next stop dealer i guess.

 

I would think that the lift kit would lead to vibrations in the driveline since you have changed the angle of the driveline causing additional stress on the U-Joints. (Get rid of the lift kit).
Did you ever slip the clutch? Or do you suspect that you might have at one time or another while pulling heavy? Clutch could be glazzed which would give you the "disconnected" feeling.

 

FYI.............Found out what the problem was , it was the index ring on the transfer case. Not sure what it was doing to make the problem but when i took off the index ring off all problems stopped. went with a aftermarkert cv drive shaft for the front works great.

 

Thanks for updating this thread with the solution. So many times people post threads with problems then, once the problem is fixed, they never post what the solution was. I, for one, appreciate you following up.