almost had enough of this trans (its my 3rd and dont want to change again) lost od then installed sonnax sure cure then diagnose from there found bad solenoid and or harness wasnt messing arround replaced govenor od solenoid transducer and internal harness. trans was never better i mean perfect then 1.5-2 mos later stuck in 3rd gear truck has bean parked since. kinda disgusted havent even pulled codes. any thoughts? and what if the plug is bad to the new harness? clips were broken before i put in sure cure.

 

my trans got stuck in 3rd a few years back, ended up being the output shaft speed sensor. its the big sensor in the tailshaft of the transmission

 

Might also be a governer solenoid/sensor problem. Mine did the 'limp mode' (3rd gear) when those went bad. Easy fix, less than $100

 

update..... contact cleaner and dialectric grease on the harness plug so far so good but only about 5 miles on it. if it stays this way new plug harness or whatever gets me that plug from the dealership

 

If you need it I can tie a hangmans noose.

 

Lol, charlie, I was about to give him directions!

 

now that would be the easy way... god knows i cant do anything easy

 

the saga continues
i may in fact have found the nicest transmition shop there is. they have had my truck for about 3 weeks threw every test they can at it dropped the pan and all kinds of crazy stuff and came up with it must be a wiring problem. and gave the truck back. i argued with them to take something for thier time and fluid and stuff but they totally refused.
now trying to find a part number for the wiring harness.

 

ok here we go some more
my parts guy is on a long cruise vaca so i messed arround a bit
pulled the 3 connectors from the cpu no sign of water bad connection dirt or anything so i put on some diaolectric grease and wouldnt you know trans worked great for 3 days. then droped off to local garage wiring guru 400 dollars later no more check engine light still stuck in third.
i dont want to wait til monday and take time off from work to bring back any thaughts like i said new solonoids transducer and internal harness and now no codes or check eng. light

 

I would amost bet that there is a bad wire hidden under the sheathing somewhere, to be intermittent like that. In order to be a mechanical problem, both bands would have to be not working in order for it to stay in third.

I trust that the valvebody was torqued correctly when it was down, as to not warp the mating surface.