P0740 code help`

specs.
99 xj 4.0 3 spd auto with od

Im throwing code p0740

got a lil bit of a noise from bellhousing area, had it checked and it isnt cracked.
some times when put into R or D it clunks into gear.
drives great, shifts fine.

Driven it this way for 5 months no problems. just light coming on and off every now and then

noticed today in od that it wasnt going into OD but when put into 3rd rpms went down. but it started working normally in a couple miles. ( A/C on )

I know what the Code means but not really sure..

TCC malfuntion or something.
checked fluid and it was still normal looking ( Pinkish ) but smelled not to good.

any suggestions?

My '98 was throwing the same code on and off for a year. The torque converter is not locking up. Your trans is still going into 4th, but does not using the lock up feature. Mine went from doing it occasionally, to all the time. From reading on this forum over the past year, it seams a new torque converter may solve the problem.

In theory, the trans may run a little hotter, since it is not locking up. MPGs may be worse, but I haven't noticed a big enough (or any) drop to make me replace it.

I've been running with the light on for the last 7k miles.

Hope this helps.

did you ever do a trans service, and what fluid did you use?

mine occasionaly throws the 740 and the lock up not happening. i have traced it to the NSS. i still need to replace mine but when im driving and i notice the lock up not happening i shift in to neutral and then back to OD and it works fine