Transmission issues

[h3bubba]

Has anyone experienced their transmission/engine going into and out of MDS with the cruise control on traveling at 60-70mph every two seconds. when i turn on tow haul mode, it goes away. i just bought an used 06 1500 4x4 with 55k on it and i think the transmission is about to go on it.

i also have a concern about the exhaust system that was put on it. whoever had it before me cut the y-pipe off and ran 2 straight pipes to flowmasters and then out under the rear bumper. will this affect the back pressure and cause the issue i talked about above. how does MDS know when to turn on and off.

thanks

 

[Redtruck-VA]

Pete, welcome..
First thing I would recommend is to download the 06 manual and start going through it to learn about the differences and uniqueness of our dodges. I don't know what specifically activates the MDS, but no doubt it has something to do with what the PCM senses as load. The straight pipes without a cross over pipe kills low end torque and 4wd being heavier and possibly with oversize tires and these will make the mDS cut in and out. Several tuners will disable the MDS which would solve some drivability issues. Gears seems to clean up a lot of these type of problem. Need more details and of course everyone wants to see pictures of the truck. Good luck..

 

[03MopaRamman]

Welcome, Good Luck and BTW, Emmisions Freindly, Right!

 

[h3bubba]

Emissions are still friendly since the cats are still there. I think that i will have to change the exhaust back to stock. i have a diablo and will deactivate the MDS and see what that does. i am afraid that it is taking its toll on my transmission and i dont want to have to rebuild that thing.

I have 3.92 gears already since i have the tow package.

Do you think putting the stock exhaust back on would fix it.

 

[Redtruck-VA]

Emissions are still friendly since the cats are still there. I think that i will have to change the exhaust back to stock. i have a diablo and will deactivate the MDS and see what that does. i am afraid that it is taking its toll on my transmission and i dont want to have to rebuild that thing.

i would suggest you set a goal you want your truck to achieve and build to that. There are certainly better performance mufflers than Flowmaster available and it may be easier to just re engineer your setup to get it right. Might be an opportunity to install headers and x-over pipe.

 

[h3bubba]

I'll turn off the MDS tomorrow and take it for a spin and see what happens then, if the issue with the RPMs hunting up and down goes away i an rule out the transmission and focus on the exhaust.

 

[Redtruck-VA]

Have you serviced the transmission? Buying a used truck usually requires bringing the maintenance up to be current. Without more information I'm pulling this from my ass, but you mention rpm's hunting, this could also be a converter not locking correctly and would certainly affect the MDS. Show us some pictures of the exhaust and most likely there will be plenty of suggestions on what can be done to correct it. Again state your goals for the truck. Do you have any codes? Have you rebooted the PCM? This helps to somewhat set a baseline to start diagnosis from and to see if any current codes pop up.. I'm just throwing out ideas.Good luck..

 

[h3bubba]

the transmission was serviced after i spent 900 bucks on a new shift solenoid. the fluid was nice and red when they looked into the tranny. the only issue they saw was that there was a lot of converter material at the bottom.

my desire is to have a reliable truck.

I turned MDS off and the issue went away. so there has to be something causing my truck to go in and out of MDS constantly on the highway. any suggestions?

 

[OlDirtyJohn]

Trannys hunting for gears is a common problem with these trucks. Mine stopped doing it after installing 4.56 gears and some transmission tuning from super chips

 

[Redtruck-VA]

Update?

I hate it when there is no followup. wtf?