1999 ford expedition xlt 1999 4x4 4.6L 4r70w
error code PO782
no "felt" slippage or incorrect shifting
got code cleared and added lucas treatment- plan on replacing all fluid today/tommorrow.
would go on at my will at 2-3 and 3-4 upshift - just put rpm above 2000rpm and instantaneously would come on during shift(I could drive it indefinitly below 2000rpm at 2-3 and 3-4 upshift and never get error code-flashing od light).had much practice at not registering error code since I drive it 30 miles a day and would never activate it-had to drive without kicking in "passing " gear power.
cleared code and hasnt come on since, tranny mechanic took it around block pushing it to 4000rpms and light never came on after he cleared it.drove it home and it never came on.
tranny mechanic said I'd have to drive it "the way you do and see if it comes back" implying I might drive "harder"- when I drive it it rarely ever goes above 3500rpm in a years driving!I baby it always!rarely ever put gas pedal more then halfway down and only "floored it once in the two years I've owned it (back when I first bought it.he says its a crack on drum weld seal.
what other possabilities are possible with PO782- 2-3 shift error?thanks! he also said 99up had good accumulater 2-3 springs and it wouldnt be that? I'm new to this .what are all the possible bad parts. he also said not to bother changing tranny fluid at 65000 since its synthetic from factory? I thought it was every 30000 around?

 

My 1999 4.6 4x4 with 4R70W, had a bad 2-3 accumulator spring, occasionally causing a brief RPM spike during the 2-3 upshift. This triggered the TCM light every once in a while. I replaced the spring ($250 parts, labor, new fluid), the RPM spike stopped, and the light never threw off a code again.

The recommended fluid change is 30k miles.

 

Thanks PaulC where could I purchase that part and other pieces around it -I think theres a valve or piston.... I got a PO782 error that just stated 2-3 shift error, tranny mech just talked about unfelt slippage through pressure loss due to a bad factory weld on drum that holds clutches where seal is welded on. Anybody know if this is bs? did not occur to me it could be a HIGH pressure error. Does anybody know if this code validates a high pressure problem as well as a low pressure problem???????sorry posted twice put under wrong one first time.

 

I had mine repaired at the dealer.

 

Thanks for advice, drove truck 40miles today no dtc's

only change since original dtc (two weeks ago) was i swapped in a quart of lucas. guess my best bet is to do complete fluid/ filter change with sythetic and additives and keep an eye on things--- since I had not done one ever -I bought it at 43000 and its now at 65000 plus who knows if it was done by prior owner at 30000 to begin with- so it might be 65000 miles old!

I'm thinking maybe after extended idling/driving 3-4hours that pressure got low that day because usually gets driven only 2 hours continuosly, but all that week we were doing the dreaded xmas shopping after doing my distribution route in which it drives/idles for 2 1/2 hours...so it was being run for 4+ hours maybe fluid broke down/pressure?

I hate that vague code P0782 2-3 shift error (real precise)
Thanks

 

I would not recommend adding Lucas additive to your transmission. Here is the reason why:

http://www.bobistheoilguy.com/images/lucas/lucas.htm

 

thanks for showing me that pounder90, had never tried Lucas before and it's funny because after I'd added and drove a couple hours I decided to recheck level and noticed 3 large bubbles embedded in oil on stick the other day , and I realized this was a no-no- same reason not to overfill tranny- so this lucas feels it can break all the rules?!

I feel its so heavy bodied... traps the air. now I just now checked it and it has no bubbles at all -maybe it loses some of its thickness after a while. with my fluid change planned I bought aamco syn blend mercon V and a bottle of prolong which is not thick bodied and I have no slip problems or material in old fluid, so I should be safe since its just super slick like duralube.

I dont feel though that products like duralube etc hurt they help with cold starts where a large percentage of engine wear takes place(this is engines though-not trannys). I know from personal experience these help. I've used in my commercial walk behinds years ago and my kawasaki and briggs engines after that always started smooth and like they were already warmed up (walk behind mower engines (12+hp) vibrate roughly when cold-real rough!) used engine additives in my 75 chevy pickup years ago and when that engine finally was rebuilt after wife drove it 20 miles despite hose leak



the rebuilder said it was the cleanest engine he'd ever seen ( this was back when additives were newer)

Same goes for newest vehicle in my garage with garage door closed you can hear the difference with and without a slippery based additive when cold (engine metal to metal noise without).
In the past I've never messed with tranny additives usually with old trannys I had they worked or they blew-- now with these new trannys they seem a little tempermental at only 65000 I do steer clear of using ptfe embedded products because of long term use buildup I've heard about. I use valvoline syn blend and every other change an additive. maybe I'll try ditching the additive now that I'm using syn oil instead of regular valvoline in my engines? hmmmmm...... With syn blends has oil industry negated effects of additives? Any thoughts anyone to combining 6 qts syn blend motor oil with say dura or pro? are syns coefficient of friction equal or better?... I have no idea.

 

pounder 90 that Lucas test is a good test for just initial lucas additions. mine had a few bubbles the 1st day for 2 hours. yesterday and today none present when cold or hot- (drove it 30 miles today and checked 3 times) and has thinned out. factors to consider- my fluid was old, when things are heated they change,blend etc....... and my mix rate was roughly 1 part lucas to 20 old fluid if you divide the ounces....what was his mix ratio?....his test had too many variables that differ from in the tranny conditions and heat plus his were testing were motor and gear oils... Lucas did bring back my fluids redness eliminating the tinge of brown in it and increased thickness- but not thicker then new tranny fluid- now adding it to thick new tranny fluid might take a while for it to thin out before bubbles go away-- I'm not willing to test it out on mine and add in to my new fluid change today thats for sure! hey still no error codes