My truck has been a wonderful performer, if a little thirsty. ODO is 95K now. In the last few weeks, the transmission has had issues with upshifting. Whether warm or cold, the tranny wants to wait until it is above 2500 RPM before it will allow an upshift.

Right before this started happening, I noticed a period of three days where I would experience major power loss at 1700 RPM+ in any gear. Whenever I had to "get on" the thottle (such as making left hand turns at busy intersections) The truck would accelerate as expected until it hit 1700 RPM, then it would stop accelerating. Instead of shooting through a gap in traffic that I and the oncomming vehicle would suspect I had plenty of room to make, I would instead seem to pause and present a handy target. I would pray that I could let off the gas and upshift to get into the low power band of the next gear to make it around a corner before my passenger side got a Ford grill makeover.

The only part I had to replace, thusfar, was a pair of underwear. The dying power has only happed once or twice since the upshift problem took-over.

At first I was thinking of TC slippage, but now I'm wondering if it might not be something else. Any Ideas?

 

Good luck on the problem. I am having so much trouble with mine its made me sick. I have your problem and slipping problems bad fuel miliage you name it. Mine has less than 7k miles. I wish I had never traded my 6 speed for this thing.

 

You have the 48RE tranny, which we use in my company's fleet. I'm not sure, but I think I have the 47RE. I'm not sure if they made the switch during the '03's with the HO's or waiting until the '04's came out. I know with the 48RE's the shifter **** doesn't tend to lock into a particular slot as well, which can cause the tranny to do weird things. Sometimes I have to bump it into neutral and back to drive or even bumping it towards 2nd without lifting up on the shifter to knock it where it needs to be. Some of my employees have reported the same situation with their trucks. Our fleet ranges between '05 and '07 model years.

 

hi , mine started doing the same the last couple months , shifting a taround 2500 all the time seem to need to give more thottle , not sure why i think sign of trans going out .

 

I experienced the same thing in my 06 48RE auto but it was with the tow/haul mode on with ~11K in tow. Seemed that once I hit ~65mph it would finally shift otherwise I had to let off to get it to happen.

 

watch you rpms when it shifts from first to second and second to third if the drop in rpms is only like 100 or 200 rpms and when it goes into overdrive and lockup it drops like 600 or 700 then it is the TC going up. the TC going out can cause wierd shifting requiring more rpms to shift and loss of fuel milage. i would suggest a TC and VB replacement you don't need to spend a whole lot for a top of the line triple disc tc and race vb just something a little better. my buddy john did a tci tc and bd vb along with a second gear band, billet band stuts and billet accumilator and front servo for about $1500 and we did the install.

 

I'll keep an eye on it on the way home tonight. If it is the TC... well, I always wanted an excuse to learn to work on a trany.

Are these all things I would need to drop the tranny for?

 

the vb you could install with out dropping the tranny. but everything else you would need to drop the tranny for. the 47re tranny's aren't really that hard to work on.

 

hopper if your truck is really a HO then it has the 48RE.

 

You CAN get a 48RE behind a SO motor. I do not understand why sooo many people think it is as easy as that. You could get either trans. It was a running change mid- year.

 

Yeah, truck is an HO. I made sure of that when I bought it. I did a little playing around with it on the way home from work. When I pulled out from a stop light, I slowly reved up to 1900 RPM. While maintaining that RPM, the truck continued to accelerate up through 30 MPH. When I continued to slowly accelerate, The engine continued to rev up, but speed remained constant. I had to punch the accelerator to get the vehice to pick up speed before I felt I felt the torque converter lock up past 2200 RPM and then up shift around 2500. As long as I was revving up fast, the truck would continue acceleration. If I reved up slow, tranny response was pretty poor.