code p0746

[mrduramax]

hey guys just got this truck from my dad( he got it new in 2002) 130 k on it now its a 2002 3500 dually all stock never any mods
sometimes it flairs on up shifts and limps on the down shifts with a p0746 code I put in a new spin on and dropt the pan inner filter is ok and clean and I did a relearn on the tranny up shifts got cleaner but it still limps on the down shift.
HELP if you can thanks

 

[Mike L.]

P0746 indicates that the clutch being controlled by A trim solenoid is coming on too slow or slipping. A bad speed sensor can cause this or a worn out clutch pack. If there is too much play in the transfer case tone wheel; that can cause it also. Bad u joint or too much play in the front drive shaft yoke can vibrate enough to cause this code.
Time to have a Tech 2 hooked up and start some testing.

 

[mrduramax]

Okay you guys are not going to believe this but I still haven't fixed this problem in 4 years lol
I have swapped all speed sensors
I've changed the rear drive shaft
I've actually change the transmission
New spin on filter and pan filter
I just took the whole wiring harness removed all the loom and tested each wire four 12 volt from the TCM the valve body plug cleaned every connector to the ECM TCM in valve body and put Dielectric grease everywhere

I'm at a loss here. And no one around here knows how to use a Tech 2

 

[mrduramax]

Mike this thing has a rebuilt transfer case you think this could be the problem it's the only part that was not changed on this truck,?

 

[Mike L.]

Mike this thing has a rebuilt transfer case you think this could be the problem it's the only part that was not changed on this truck,?

Yes. That's why you need to start with a Tech 2 and watch what the output speed sensor is doing. Take a movie with it and duplicate the limp. Then watch the movie and see what the sensors are doing.

 

[mrduramax]

thanks il report back