Ram 2500 6.4 Shudder NOT MDS

[klrobert]

I've had three different heavy-duty ram trucks and they would all have a shudder when towing and pulling hard. It was definitely in the driveline. I chased this for years on the '08 I had and never found the cause. I think it is just the Ram truck.

[emm-dee]

Originally Posted by Tomt996

Hello all,

I recently purchased a 2017 Ram 2500 6.4 hemi. At about 1200 miles it developed a shudder, almost exactly like it has a miss. It occurs when towing (my trailer is 6500 lbs loaded) & the tow/haul is engaged so the MDS is disengaged. It also occurs when empty as well, MDS disabled by tow/haul or gearshift or not. Usually between 45-70 mph.

Its been in the shop several times already & its not throwing any codes. Dealership has checked tires for balance, all mounts, driveshaft angles, changed the EGR no help. A star case has been opened but nothing yet.

My buddy has a 2016 & says his has done that since new. Again it feels like it has a miss, running on 7 cylinders. MPG & power are fine, just very frustrating & annoying to drive. Doesn't happen all the the time either.

So for you that have the 6.4, does your do that? Has anyone had repairs to address a similar issue? Any suggestions or advice would be greatly appreciated.

Urban legend. MDS is not disengaged by selecting tow/haul mode. The only way to disengage it is to use the manual shift buttons to anything other than the "auto" mode.

[goduc]

Torque management.

[aceinspp]

There is a new flash code fix. The Torque converter and MDS are not in sink. There is a TB service bulletin out on this to fix. If you need the number for the bulletin let me know. Later RJD

[jbhodj]

Originally Posted by aceinspp

There is a new flash code fix. The Torque converter and MDS are not in sink. There is a TB service bulletin out on this to fix. If you need the number for the bulletin let me know. Later RJD

This ^^^^ is probably the issue. My dad had same issue in his Ram 2500 and resynced the MDS and torque converter. Also check Ramforumz.com to see what they say

[RSchleder]

You might try the Ram Forum as there's a lot of experience and knowledge relating to Ram trucks residing there. Good luck!!!!

http://www.ramforumz.com/index.php

[Crusadernoob]

Originally Posted by klrobert

I've had three different heavy-duty ram trucks and they would all have a shudder when towing and pulling hard. It was definitely in the driveline. I chased this for years on the '08 I had and never found the cause. I think it is just the Ram truck.

So after not fixing the first one, you bought 2 more? THAT'S dedication!

[aceinspp]

Originally Posted by RSchleder

You might try the Ram Forum as there's a lot of experience and knowledge relating to Ram trucks residing there. Good luck!!!!

http://www.ramforumz.com/index.php

My info was from direct contact with Head service manager at my Dodge dealer. He has fixed several of the trucks already. He is not just a paper read guy he knows mechanics. He also owns a 2017 Ram 6.4 Later RJD

[sellis1053]

Originally Posted by emm-dee

Urban legend. MDS is not disengaged by selecting tow/haul mode. The only way to disengage it is to use the manual shift buttons to anything other than the "auto" mode.

Mine is disengaged when I select the tow/haul mode.

[emm-dee]

Originally Posted by sellis1053

Mine is disengaged when I select the tow/haul mode.

How do you know it's disabled?

[sellis1053]

Originally Posted by emm-dee

How do you know it's disabled?

If you've driven one for very long, you can tell the difference.

[emm-dee]

Originally Posted by sellis1053

If you've driven one for very long, you can tell the difference.

Got a few hundred thousand miles with them. MDS will rarely come on when towing but if I let off the gas and coast it activates even in tow/haul mode. Not towing I see it come on a lot with the t/h selected. Can hear it and feel it.

[sellis1053]

Originally Posted by emm-dee

Got a few hundred thousand miles with them. MDS will rarely come on when towing but if I let off the gas and coast it activates even in tow/haul mode. Not towing I see it come on a lot with the t/h selected. Can hear it and feel it.

I also found this on another forum:

"The 1500 and 2500 are possibly different in tow/haul-mds programming.

I saw a Ram engineer post in another forum that Tow/haul will disable MDS on the 6.4 2500. Also locking out 6th gear in manual mode will disable the MDS.

Just what I read on one of those "ask the Ram engineer" chats about the then new 2014 6.4 Ram 2500.

I cant speak about the 1500s, I've only searched about the 2500s."

[Marcus80]

I have a 2016 Ram 2500 6.4 Hemi and it does not shudder at all, pulls really smooth and even when I have my trailer and when I don't... Could it have to do with the variable cam timing? And they do have 16 spark plugs, so it could have a miss.

[m2kamp]

23k on my 2016 2500 6.4L. No vibrations at any speed, towing or not.

I think a computer flash update is needed for your truck. Let us know what the fix was.

[Tomt996]

I appreciate everyone's input on this. It appears I'm chasing the same vibration/shudder that hundreds if not thousands of other Ram owners have.

Its not an MDS issue as many have indicated, I can feel when the MDS kicks in & out. I've had the tires roadforced balanced at an independent shop but I only did that to eliminate it, didn't that that was the fix.

Took it to Ram last week, service manager took it for a drive and said "yea, its got a vibration it shouldn't have". Thought it might be a valvebody in the trans, not sure about that & opened a STAR case. No software updates for my truck.

I'm going to a driveline specialty shop today to let them have a look at the driveshaft. If any of you have this, its absolutely in the drivetrain, not sure where what exactly but thats where it is. And RAM knows there is an issue with these trucks.

[Lins]

That's too bad, good luck with getting it fixed. One video in the link I sent shows a dually with the rear wheels on one side wobbling. His theory is his axle shaft is not straight. Other think it's a resonant issue. Hopefully they take care of you