i am probably the enemy on here, as i am on most car forums but here goes anyway: i am a ford technician at a dealership. we got a 99 5.4 F150 with the 4r70w in on trade. some guy buys it and complains of a harsh shift. well, a very inexperienced mechanic looked at it first (don't know why) and he first replaced the EPC solenoid, then the whole valve body trying to fix it. well needless to say it didn't work. then they gave it to me. well the first thing i noticed, being a mustang fanatic, was that it had a b&m shift improver switch. well i unhooked it from the PCM wires and completely removed it from the truck. tried it again, still shifted hard. then i noticed a strange code in the PCM which prompted me to see if it had a "chip" in it. well, i was right and it did have a diablosport chip in it. i removed it and drove it again, thinking i surely had it fixed now. well guess what, it still shifts hard. now for my question: do you guys know if there are any other devices they install, possibly with the b&m shiftplus switch, to firm up the shifts? it feels like the epc pressure is jacked to the max at all times. it almost chirps the tires when you come to a stop it downshifts so hard. plus it bangs into gear when shifting out of park. any ideas? i would be very grateful for any insight. additionally, does anyone wanna buy a diablo chip and b&m shiftplus kit?

 

Try resetting the computer, then taking it for a ride.

 

I'd love to have that over the sloppy, hesitating, shift charecterisics that Ford designed into this tranny. I do now with a new PA Valvle Body and Superchips Microtuner.

Seriously, if you put in a new VB, that would discount any idea of a shift kit, such as a Transgo. If you've taken out the chip do try and reset the PCM. If that doesn't work try and do a reflash of the PCM as well.

If you took out the Chip without disconnecting the battery first, you performed a big NO NO.

John

 

yes there ia whats called a "boost valve" that is designed to increase line pressure, which I'm sure you already know would cause exactly what you described to happen. Here is a link to one for a 4L60E, but you can also get them for a 4R70W.
http://www.kdsperformance.com/boosval5004l.html

 

i already reflashed the pcm before, i forgot to mention that. also unhooked battery. i'm not familiar with the "boost valve" though.... where might i check for that? has anyone here put one in a 4r70w? btw thanks for the info so far.

 

If you scroll down and read about the boost valve in this link you will see its function is to increase line pressure to match torque. It is my opinion that maybe this valve could possibly be sticking and causing high line pressure. Maybe you could run a line pressure check on the customer's car and see if it is a little high.
http://www.baumannengineering.com/aodcat.htm

 

Didn't he say he replaced the valve body? If so then the valve should've been in the old one, correct?

John

 

thank you all for the help, i figured it out today. the driver in the pcm for the epc solenoid has burnt out, and when there is a problem epc pressure defaults to full pressure. so it's gonna need a new pcm. looks like it was probably caused by the b&m shiftplus switch. thanks again.

 

kwester Just so you know your not considered the enemy. There are actually several techs here. You should feel free to check this site out to verify information and to pass some on. You work on all the Fords, right? Well we are mostly into the F150's so many of us know them pretty well.

I think it's a good thing to have techs on this site. Maybe more will show up and we won't ever have to bring our trucks in for diagnostics again!

Absolutely feel free to pass on some info on what you Mustang folks are up to these days. There are many of us that look at whats going on with the Mustangs to see what we can come up with for our trucks.

Have fun!

 

Kwester, I agree with what Wittom says. Hang around!

 

I for one appreciate your honesty and feedback on the problem. I'm always soaking up input and look forward to hearing from Ford techs on the forums.

Pete

 

You are definetely *NOT* the enemy. It's great to have you and hope you stick around. Any insight in how I can keep my truck up and running in tip top shape will be greatly appreciated by myself and others.

Welcome!

 

kwester look around the dealership and find the dark blue binder that says AODE (if you havent already) It is a great source of info such as oil diagrams and valve descriptions and functions