So my 2011 AWD Hemi Crew (135,000 km's) has been having the "clunking" sound on acceleration from a dead stop issue for a while now. I had it up on my buddies hoist and checked for bad bushings, loose drivetrain, etc., and it all seems good under there (apart from a rusty looking exhaust). The symptoms have been showing up around 10 - 20 kph and only happens when accelerating from a dead stop. It didn't matter how hard I accelerated either.

Searching online resulted in probable causes from motor mounts, load leveling shocks, to transfer case issues. Some claimed that new T-Case fluid helped but only for a while, others had their T-Case replaced (under warranty) and it fixed the issue. I decided to start there by replacing the fluid. The manual states to use the specific Mopar NV 247/245 T-Case lube. I went to the stealership to buy some (the local auto parts store couldn't get it) and they said that they don't use that type of fluid anymore and they just use ATF. I thought this was a bit strange and so I just ordered some of the NV 247/245 online.




I didn't take and pics of the old fluid that came out of the T-Case but it was definitely ATF. It was a blood red colour and was not clear at all. The NV 247/245 fluid that I replaced it with is more of a clear light honey colour.

The end result is that the "Clunk" is gone!!! The way the Durango accelerates now is a little different too. Seems more solid if that makes any sense?

So I'm wondering, for those more knowledgeable than I, is there a clutch pack or a disc setup inside the AWD T-Case that needs the specific formula in order for things to engage smoothly? Properties that are in the NV 247/245 oil that isn't in the ATF, or does the ATF break down sooner than the NV247/245? Or possibly it's as simple as just freshening up the oil regardless of type?

Either way I'm glad it's fixed!

 

Yes , I had my transfer case fluid changed along with the differential fluid and the clunking stopped. There are two types of transfer cases that use different fluids as shown in your pictures. The one that uses ATF uses more fluid than the one that takes the special Mopar lube.

 

I had the truck to the dealer 3 times for that problem and they couldnt figure it out. Guy said it might be a mount. Since when does a mount clunk half way through first gear.
Stay away from dealers unless its warranty or recall work !!!