I hope I'm putting this in the correct area.

So I have a 2006 1500 Big Horn Edition 5.7L 2 wheel drive with 18,000 miles. After owning the truck for a few days we started noticing a shudder when letting off the gas at 37mph. Took it to the dealer and 3 weeks later they have decided to tell me that the MDS kicks in at 37mph and that this is causing the shudder and that Dodge is working on a upgrade for the system because many people have been complaining of this.

Does anyone else know of this issue? Or are they feeding me a line of BS? To me it feels as if it's a bad U-joint but they swear they U-joints are fine. And also when I bought the truck I was told MDS did not come on the Rams until 2007, and that my truck did not have it. But now all of a sudden I have this option?

 

Your truck has it, ALL 1500 series Hemi's except Megacabs built from '06 on have it.
I can't speak from experience, because my '04 does not, but I've not heard of it, plus there is no certain mph that it kicks in or out. It does it based on the PCM determining when the engine does not need the full 8 cyls. to maintain a constant speed.
So in my opinion, you're getting a line of BS from the dealer.
Could be anything from a U-joint, ball joint, tire balance, tire defect or drive shaft out of balance to name just a few possible causes... Now if you were to say you felt it at any speed when you let up on the gas, I'd be more inclined to think MDS...

 

Thats funny you mention that because when I'm going about that speed I get a very noticable vibration when the MDS kicks on. I'm used to it but when it gets old I just click the shifter in tow/haul mode. But ya thats funny that it only does it at that speed, I'm guessing it's because of the really low RPMs (1000-1500rpms)when the MDS kicks on at that speed.

 

Yep, it can come on at any time under a light load.

 

Well I'm glad to hear someone else has the same issue. Hopefully if and when Dodge makes this upgrade and flashes the system it will take care of this. It can be quite annoying lol.

Thanks for the help everyone!

 

Anytime!

 

Total BS from your dealer. MDS is totally transparent when switching (it only takes 40 milliseconds, fer Pete's sake!). Easy fix, though -- don't let off the gas at 37, do it at 36 or 38 (sorry, couldn't resist). Could this be a transmission shift? Every now and then I can feel my tranny downshift.

 

They ruled out any "trans issues". They replaced the torque converter and some other crap and it's still there. I've also noticed that it's doing this not only at 37mph anymore, it's rangeing from 35-40mph now. So whatever crap they fed to me, it better fix this because I didn't buy a $22,000 truck to be having these issues already. I may be a girl but I know when someone is blowing smoke. I straight up told the dealer this better fix it or they can have it back and I'll go buy a Chevy LOL