bwanye

In May I bought a 2004.5 600 with a 48RE tranmission. This is the first diesel I've owned. The question I have for anybody that may care is: The transmission shifts much different from any automatic I've owned (although they have all been gas). It seems to search for gears when slowly accellerating and at slow speeds around town. Is this normal for the 48RE or should I take it to the dealer for a check-up?

Hannibal

My 47RE is the same way. It's totally different from the 47RE I had in my '01.5. If I take off from a stop with moderate throttle and have to let up a little just as it shifts to second, it acts like it gets confused about which gear to go to. It feels like it shifts to second, back to 1st and then back to second only to be in third when it's done. If I disconnect the batteries for a few minutes and reconnect, it's good for a while. I think it has to do with it being a "learning" transmission "TCM". I don't like it at all. I'd much rather have the stupid program my '01.5 had. Or an empty and tow haul mode. There's too many variables that can't possibly be programmed into a "learning" tranny. But... a co-worker's Volvo S70 turbo (his wife is in real estate) does the same thing. It really takes away from the enjoyment of it.

Dodgezilla

Mine does it too. Especially when I'm in traffic. It has gotten a little better with the DTT valve body and hopefully it will get even better with the DTT converter installed this weekend.
It shifts fine under light throttle or heavy throttle. It's just the middle range where the erratic shifting happens. You can try taking it to the dealer but mine told me it's normal.....

N.Johnson

I also have the 48Re and it will act the same way if i let it. Empty and no trailer the tranny doesn,t know how to shift properly. Under load (weight) with steady go pedal pressure it is the best work auto tranny I've ever driven. Empty is another story, the computer sensors get feedback on load, throttle position and torque so the pedal position is critical for smooth shifting. Remember these are computer controlled drive by wire machines. I've found that learning the the rpm shift points and metering the accelerator (ease off) accordingly unloaded takes a little practice. Remember it is a 3/4 ton heavy duty pick-up with a medium duty cummins engine. These vehicles do not shift like dad's olds......LOAD IT UP.... or buy a SUV.

natstayl

Take it to the dealer, you may have a faulty/misadjusted TPS (throttle pos sensor) particulary if when you first took delivery you drove it like your old gasser. Because the shift points are at lower RPM's, driving it like your gasser with the accelerator close to the floor during upshifts or moving the shifter manually causing the engine to bump the rev limiter, the engine control computer may be misreading the TPS.
Nat

MikeyB

A quick way to check is to have the computer re-learn the TPS range. Just disconnect the batteries for about 15 minutes and reconnect the terminals. Turn the ignition switch to ON, DO NOT start the truck, slowly press the throttle all the way to the floor and slowing bring it back up. Turn the ignition switch OFF. Now start the truck. This allows the computer to remap the TPS sensor.

MikeyB

falcondan9570

The tranny is "programed" to get into HIGH gear as soon as possible..If you give more pedal, then it will shift higher in the rpm ranges....

bwanye

Thanks for the input everybody. I called the dealer and they said it's normal. I did notice while heavy hauling/towing it doesn't do it.

Regarding the comment to "load it up... or buy an SUV" from Johnson. Why would anybody load up a pickup for no reason? I operate my own construction business and on occasion I've towed over 16,000 pounds with my Dodge. There is no reason to load up a pickup unless you have to. Even the 600 was squealing like a pig to move a 16,000 pound trailer up hills. Kind of wish I would have got the 6 speed.

Hannibal

I have to agree with N.Johnson, While towing our 10,400 lbs 5th wheel, even the 47RE works like a champ with the current program. It even keeps the TC locked in O/D or 3rd down to about 15mph. Shifts are firm and it holds 3rd until I let off a little while accelerating. It doesn't downshift from O/D in the hills even at full throttle above 55mph. So for towing the program is great. But running empty it's often confused.