You can definitely feel a difference.....i have been mostly driving around town with OD off....im still waiting on an answer from Al about the 2nd prime thing he was talking about....

 

Trucks with the 545RFE auto box should NEVER go WOT in drive at 50-60 mph. With or without this mod, WOT shifting is a BIG no no with these autoboxes in drive at those speeds.
What happens is, there are 2 second gears in these boxes. One is the 2nd prime passing gear and one is a slighlty lower ratio second.
One is for smooth cruising and the other a more aggressive passing gear on the freeway.
Anyhow, this is another Achilies heel in this box, as the clutch packs/bands to select this 2nd prime gear, are very weak and at WOT it apparantly doesn't take too much to grenade them.
What people must do at these speeds, is either, manually select 2nd with the shifter or push the OD button to off, which makes the box pre-select the more agressive 2nd prime passing gear.
Sorry for the vaigness of this, but it's been a loooong while, since I had to remember this stuff.
Do a search on 2nd Prime and you should come up with something.

shadow11.........it does work for a 4.7.

Here's step by step pics of how to do it plus a discription.

Its the yellow wire with the green strip. I don't know if you have an aftermarket air intake, but I will give you the details for a stock box. There is a nut on top of the airbox that has to come off. There is a rubber bushing in the hole make sure not to lose it. There is also a pin that the airbox sits in down by the wheelwell in front of the air box, that just slips off of it. Now that the air box is up and out of the way, the TCM, is up by the passenger headlight. That is where you remove the wire. Take the cover off of the harness that goes into it. In case you don't know what it is, it looks like a box with cooling fins on it. Then there is a bolt holding the harness in take that out, ( it doesn't come out all the way, just loosen it and pull the plug out) Look for pin number 10, that is your wire. It is on the back side toward the bottom. Now you will need a very small flat blade screwdriver. There is a red clip that holds the wires in, take that off by prying it up on the right side. Then looking down in there make sure you have the right hole and you will see a plastic tab holding the wire in, there are a couple of holes that are empty check them if you don't understand what I mean. Take your flatblade and push up the tab down in the hole and pull the wire backwards out of the hole. It takes a little jiggiling but it will come out. Tape it up with black electrical tape and then put the red connector back in. Just reverse the process from the begining.
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I'm sorry I have a confession to make here but, I have stolen plagiarised, copied pictures & descriptions and various bit's of information from other people and sites, to post this here.
I appologise to everyone for this, but in my defence, it was the ONLY way I could get this info out to everyone with a 4.7on how to do this mod, as I have ea Hemi.
I hope this is OK and people understand that it's in the interests of making every 4.7 FAST and props to everyones pics etc. I take NO credit for this info on the 4.7 at all.
Al.

 

Al
So so the same rules apply when you are stop and go driving (as far as the OD is on or off)

 

Yes.
You MUST NOT wot at highway speeds or stop go at speeds of 45-60 mph whereby any 2nd gear will be selected under WOT conditions.
If you do, 2nd prime is selected as the most aggressive gear of the two second gears. The auto box senses this kickdown as a request to accelerate/pass.
So the upshot is, many experienced and far more knowledgeable guys have said that with the clutch packs/bands being weak on this 2nd prime, damage over time WILL occurr if you hammer the autobox like this.
This is what primarily destroys the 545rfe boxes.
Put OD to the off position or select 2nd gear by using the shifter, then romp on it.
It's apparently much kinder to the autobox doing it that way as max torque/horsepower is not being forced into the autobox and it promotes longevity.
Hope this helps?
Al.

 

I don't know about Diablo or SCT, but Superchips will get 2nd Prime the hell out of the way for WOT operation if you request it. Mine's history...

 

The mod won't cause the failure. Dodge's bad idea will do it on a completely stock truck. It just depends on how you drive it.

This can accelerate the issue if you drive WOT a lot (like I do) but I haven't had an issue in 20k miles with a programmer and let's just say I use WOT a lot.

 

first question does this work with '02's as well?
second, does the '02 4.7 have the 545RFE?

 

still can't do this mod, i don't have any of these boxes. i'm starting to think my truck is mislabeled and is actually an '04.

 

My truck doesn't have that little box up by the passenger side headlight. Would it be some where else?

 

Hey Shadow11, I don't know anything about the 4.7's as I have a Hemi.
I posted up all the infor about the 4.7 I had. I guess you just need to look harder for this Autobox controller.
Can anyone else help him that has a 4.7??
I also just noticed that my truck, before it was imported into the UK came from the Tomball area.
It has a set of tints on the windows from TomballTinters 351-1925.
From the carfax I know it was also from that area.
Small world eh?
Al.