Sorry in advance for the long post, but I want to be thorough. I have an '03 2500 4x4 with the 5.9 Turbo and a 48RE transmission. Truck has just over 155,000 miles on it. Truck itself is virtually stock, but have recently replaced balljoint, PS pump, water pump, exhaust, several axle/driveshaft seals and U-Joints.

Started having a problem with the transmission shifting over the last 6 months or so. Initially, it would lose 1st gear when starting out from a stop...seemed to be during hot or cold weather. Then the shifting problems started getting more and more pronounced until proper shifting is the rare occurance.

Here are the symptoms:

• Loses 1st and 2nd gear virtually all of the time.
• Truck basically starts out and stays in 3rd gear unless traveling at speed and enters 4th gear (and OD) fine.
• When slowing, truck does not downshift into 2nd or 1st.
• When starting from a stop, truck will not shift into 1st or 2nd. Can use shift lever to put truck into 2nd most of the time, but rarely can get into 1st.
• Sometimes feel the transmission kick when stopped like it is hard shifting into 1st, but does not stay in 1st most of the time.
• If I shift into Neutral, then into Drive, it sometimes stays in 1st or 2nd, but rarely.
• Every once in a while, truck will start shifting fine. I routinely drive the truck for work throughout the day and when it shifts right, it continues to shift right until the truck is shut off for any length of time. No rhyme or reason to when it works.

Just changed out fluid and filter and did not seem to have any affect. When changing fluid/filter, did not see anything in the pan except for filings caked onto the magnet. No other pieces observed in the pan. Exposed internals of the transmission seemed in good condition (nothing apparently broken, cracked or work).

I am getting ready to call a few local transmission shops (hate the pricing of the dealerships) and was hoping to try and get a handle on the problem first. Especially if its something that I can maybe fix myself. Any advice you all can give will be greatly appreciated.

Thanks in advance.

 

If you have the APPS on the drivers side of the block, you can try adjusting the tv cable. You will have three cables leaving the rear of the APPS, one goes through the firewall to the throttle pedal, one goes over to the cruise control servo under the driver's side battery, and the one you want, goes down to the tranny.

As the tv(throttle valve) cable exits the rear of the APPS, it is held secure in a black plastic clamp with a white plastic snap retainer. You will notice the cable sheath is grooved, each groove about an 1/8" apart, mark the first groove behind the clamp with a silver sharpie or something you can clearly see. Grab the white plastic retaining clip and pull it off the clamp towards the inner fender, away from the engine block, this will allow the cable sheath to move freely in the clamp. Pull the sheath towards the firewall one groove and push the retaining clip back over the clamp.

Test drive, see if it helps. You can try moving it a few times, but this is why I had you mark the original spot... it could be your govenor solenoid going south, or something more serious. This is kind of a temporary fix, and by marking the original sheath position, you can return it to that position.

This is a pain to see, under the intake horn. I removed my intake horn to see what I was doing, but after doing it once, I would not have to remove the intake horn again.

If you do not have the APPS on the drivers side of the block, I just wasted keystrokes....

Good Luck, Jess

 

I have the identical problem with my '03 and was wondering what you came up with as a fix. I'm thinking APPS but not sure...

 

Turns out it was the governor sensor and solenoid. Changed them out and problem fixed. Although now transmission now hunts for 2nd or 3rd at low speed. I've done research and this is common, with only fix being to change out sensor/solenoid again. Will probably do that again if/when this gets too bad.

 

Try upgrading to the GM solenoid/transducer the next time you replace it, seems to work and last alot longer then an OEM replacement unit.