The torque converter in my '02 Supercrew is locking in 4th gear, or during the 3-4 shift. Is there anything I can do to fix this? Thanks for any help.

 

The TC is supposed to lock in 3rd and 4th - are you saying it's locking up too soon? How do you know it's locking up?

 

I thought it was supposed to lock in second. When I have o/d off, and turn it on, if I'm not accelerating, it will shift once and fall on its face. If I'm accelerating slightly when I push the button, it sounds and feels like it shifts two more times.

 

That sounds normal for a stock tune. Do you have oversize tires and/or any other mods? Why are you manually turning O/D on and off?

 

I have to have it off while driving at speeds of 55 or less or it runs at too low rpm's and will constantly be downshifting at any throttle increase or the slightest uphill road.

I do have slightly larger than stock tires, but have for the past 10 years and it was never an issue until recently. I've tried to video my gauges with my phone and it didn't turn out too well. I'll have to mount my gopro and try again as soon as I get a chance.

 

Here is the vid I made a while back.

 

That's normal.

I'd get a programmer and a set of custom tunes, both to correct the speedo/odo for the larger tires and to give you (the tuner) the ability to modify the trans behavior to more suit you.

By the sound of the exhaust, I think you may have more mods than just larger tires........

 

I've got a Superchips handheld that I used to correct the speedo, which wasn't much. It was only about 2 mph off. I removed the rear cats and have Cherrybomb Extremes. I would like to learn how to tune myself, or at least adjust some of the settings, but that would have to wait until I have another vehicle to fall back on incase this one goes south.

I need to do some data logging to find out when it's shifting vs the tc locking. Like I said, it hasn't always acted like this. I just want to make sure it's working as it should be. Thanks for the help.

 

Oh! A Superchips is DEFINITELY a mod...........as are rear cat deletes and cherrybombs.

Return your tune to stock and see if that makes a difference.

 

I didn't mention those before because they aren't really performance mods. I'm on the stock tune. I only used the handheld to adjust the speedo. Without tuning, the exhaust change didn't do anything for me. I've had 7 different exhaust configurations in the last 12 years, in search of the sound I liked most. I haven't noticed anything in particular change the way the trans or tc felt.

 

How do you keep from throwing a CEL with 420 and 430 codes with no rear cats, or do you just ignore the CEL? If the CEL is on, you should scan it to see if there are any other codes. Has the O/D Off light ever started flashing? If so, there's transmission codes stored too.

 

I thought that removing the cats would throw the light, but after a lot of reading on forums, I found that it wouldn't on the 5.4L.

I haven't ever had the o/d light flash, and I've had a shop run diagnostics on my truck. The Superchips didn't really make any noticeable gains in performance when I got it, but I kept it to read codes when I got them. A few years back I had a cop go bad, but it never gave me a cel. I had to get a shop to put their computer on it so I would know which one it was. They ran a full diagnostics check and didn't find anything else.

The only other issues I've had with my drivetrain is when coming to a stop, just before I came to a complete stop, there was a hard jolt, like someone rear ended me. Once, it happened about 2 or 3 seconds after I was at a complete stop. I have no clue what it was. I've mounted my gopro under my truck watching the rear axle for axle wrap and it didn't seem to move. I've also notices driveline "slack or slop when releasing the brakes from a stand still, but before I touch the throttle. I'm in the process of replacing my u-joints and leaf spring bushings to eliminate those possibilities.

 

The clunk is probably a dry slip yoke in the driveshaft.

 

Thanks. I'll be taking care of that while doing my u-joints. I will have owned my truck for 12 years this month and have no intention of getting rid of it anytime soon. In fact, I plan on buying an '02/03 Harley F150 this year.

 

When was the last time you did a full tranny fluid exchange?