While pulling travel trailor with my 06 2500 ctd with a auto trans, up in the mountians at slow speeds, the trans shifting was horrible, as soon as I would need to let off the throttle, the trans would shift very fast into a higher gear, I would loose all my momentum, and would take a bit before it would downshift, this doesn't seem right, Anybody experience this

 

I hope you are NOT in O.D. Please tell me you are NOT in O.D. towing. All so a trans cooler would be a good idea.

 

A 2500 ctd will have a big *** factory trans cooler installed already.

 

Not in overdrive, but did have the tow/haul engauged, And on the freeway the tow/haul will allow it to go into overdrive ive noticed

 

Do you know if you have the 47 or 48RE transmission or the 545RFE?

 

My down shifts pretty hard. The shifting up when you get off the throttle mine does that. My other truck did to. I think it's normal.

 

I think its the 48re , auto

 

Some other notes, I have a 5" MBRP from turbo back exhaust system, but every other year for calif smog, I take a section out and put in the factory {filter}back in, I guess that's what it is. And it seems to have more back pressure when its in, and seems to tow trailor better with it in, if that makes sense.
And with the 35" tires, im wondering if I need to change my diff gears.

 

You're going to have to give us some more details.... most of the 2500 Cummins powered rams come with 3.73 gears... which aren't "great".

Have you checked your transmission fluid level?

Honestly... if you let off the throttle going uphill the truck will upshift... that is generally how they work... even in Tow/Haul mode. Also, I am betting that your truck does not have an O/D Off feature (if you hit tow/haul button again), so all Tow/Haul is doing for you is preventing frequent shifts while cruising at a steady speed on the highway, and also increasing the RPM point where you upshift... it also "MIGHT" put itself into 3rd gear while slowing down in order to improve braking performance.

Also, that "filter" for your exhaust does add some back pressure, which the engine is likely trying to account for, which will show a different load on the engine, which is likely why you're seeing poor performance. You may need to get a CARB legal tuner to help you increase the performance a bit to account for that missing filter...?

Changing the diff gears to 4.10's will definitely help if you're frequently towing in hilly areas for sure... but if the majority of your driving is on highways you'll see a decrease in your fuel economy.

And 35" tires are definitely not helping you at all while towing... but as long as they are load rated as "E" then you should be okay to tow some pretty heavy loads.

Bottom line is you have to learn how to drive the truck in those situations to prevent an up-shift... that may mean modifying the way you manipulate the throttle when approaching an incline, as well as even manually downshifting the truck into the "2" position in order to keep the truck in a lower gear and limiting your speed.

Hope that helps.

 

The truck does have the O/D Off mode also, it comes on when I hit the tow/haul button twice, and I still have the filter, or cataletic converter, or resonator, not sure what to call it. And its going back in due to the California smog law, and I think im just going to leave it in full time now, its a hassle to keep taking it in and out. But before the law went into effect, doing a bigger exhaust system, and allowing the exhaust to get out quicker, or to let it be cooler, seemed to be the thing to do on the diesels back when I bought the truck in 06.