Transmission shifting

[Nick_T59]

I just bought a 2002 ram 2500 5.9 Cummins with the 47re trans. I noticed while I was driving it that around 40mph it would try to shift but would go right back to the gear before and it would just keep doing it, idk if it’s a slip problem or if it’s actually trying to shift. If anyone has had this problem or know about it some help would be great, thanks.

 

[Fast69Mopar]

I just bought a 2002 ram 2500 5.9 Cummins with the 47re trans. I noticed while I was driving it that around 40mph it would try to shift but would go right back to the gear before and it would just keep doing it, idk if it’s a slip problem or if it’s actually trying to shift. If anyone has had this problem or know about it some help would be great, thanks.

At 40moh two things could be occuring. Either the trans is attempting to shift into 4th gear or the torque converter clutch is engaging and disengaging.

To determine what is happening, press the O/D button to disable 4th gear and go for a drive and operate the truck under the same conditions.

With the O/D (4th gear) turned off the trans will shift 1-2-3-TCC. If you feel the same thing happening as before then we assume that the torque converter clutch is engaging and disengaging.

If you do not feel the same thing happening then we can assume that the trans is shifting from 3-4-3 and is unable to maintain 4th gear.

If this is the case where the trans is shifting from 3-4-3 there may be a problem with the TCC/OD Solenoid or an issue with the 4th gear clutch.

Before we get ahead of ourselves and condemn the trans let's do the simple diagnostics first and that starts with a transmission fluid check and a test drive.

Next, we get a scan tool connected to see if we have a transmission DTC set.

 

[Nick_T59]

When it was doing it that’s the first thing I did (put o/d on) and it wasn’t slipping or anything so I will check what you said about shifting 3-4-3 and maybe replace some stuff. Thank you.