2002 dodge ram 4 wheel drive diesel wont shift. there is enough fluid in transfercase and transmission. does anyone have any thought on what could be the problem thanks in advance.

Information is key to just say it doesn't shift is useless. What doesn't shift, the transmission or the transfer case? Is it an automatic or a manual? Does the shifter not move, or move with little or no resistance? Does it have reverse? Is it stuck in second or third? What Trans is in it? Check engine light on? Be specific about what works and what doesn't and how exactly it behaves.

the transmission wont shift, the transmission is automatic,the shifter does move with no resistance, it does have 1 and reverse, not sure which transmission, no check engine light on, truck will not shift even at a higher rpm, hope this helps some thanks.

You are most likely going to need a scan tool to diagnosis this issue. The transmission has an electronically controlled governor. The PCM controls the governor pressure solenoid by using data from several inputs to the PCM. Just because there is no CEL, doesn't mean there isn't a stored fault code in the PCM. If you don't have access to a scanner and just go rogue, My first place to check would be the output speed sensor on the transmission. When it fails the PCM cant determine the transmission output speed and will not command the trans to shift. If you are lucky this will be your problem. They are only around $20 and simple to change. They are mounted externally on the drivers side rear of the trans. No need to drop the pan. There will will be minimal fluid loss but some fluid will come out. Just unplug the connector, unscrew the sensor and remove. Reinstall a new sensor in its place and cross your fingers.

won't shift...

stuck in 3rd? stuck in 1st? stuck in OD? stuck in reverse? torque converter permanently locked, and it stalls when going into gear?


Looks like you have first and reverse gear only? have you tried manually shifting through the gears while driving? or is this only while in "D"?