Yep, as I put more and more power into the 6.0 the tranny was getting really slow to go
into 3rd and 4th. So I just kept increasing the shift firmness at 2-3, 3-4 on my Edge.
Had the 2-3 at 11% and 3-4 at 9% over stock. Firm

Then it started kicking in and out of 3 or 4. Once I lost all drive and the tranny light was flashing.
The classic over pressure valve symptom.

So I dropped the pan, installed a PTP Modified Clutch Valve and a Transgo sensor plug.
Put a big pan on and filled with $160+ of Mercon SP. (man, that price went crazy !!)

Drove it in the parking lot and 2-3 shift was like getting hit by a train.
I now have 2-3 firmness at 4% over and 3-4 at stock and 3-4 could even
go down another 1%. (don't know if the Edge will go neg but will find out tomorrow)

I have been kicking the crap out of it all week and not a hiccup. Towing the boat tomorrow so
fingers crossed.

 

I hate to say it but run it without the Edge unit. Edge has a bad rep with the trans on the 6.0L trucks.

I don't know what pan you are using but you paid too much for no additional benefit.

 

I didn't intend this post to be about tuners or volume of ATF.

There just seems to be allot of posts on this issue and if you google it
you find that there is a ton of bad info. Ford says you have to replace tranny.
It is really a design flaw from Ford. They engineered the tranny with pressure
sensors for each clutch pack and then never implemented them. So if you have
a slipping clutch pack the ECU keeps calling for more pressure until the over
pressure valve opens and dumps all pressure. Bang out of gear, valve closes,
slam back in gear and repeat. In a perfect world Ford would recall all 5R110s
and 6.0s for that matter. But that's yet a different thread.

So what I was trying to say is that this simple fix is working for me.