Shift Pointers
- Subject: Sudden no-move condition
- Unit: AX4N; 45RFE
- Vehicle Application: 2003 Ford Taurus; 1999-up Dodge
- Essential Reading: Rebuilder, Diagnostician
- Author: Wayne Colonna, ATSG, Transmission Digest Technical Editor
Just recently my uncle backed out of his driveway with his 2003 Ford Taurus wagon (AX4N transmission), put it in drive and had no movement. He then put it in reverse and still had no movement. So there he was stuck in front of his house, going nowhere fast! And I must say that if you are going to experience a sudden no-move condition with your vehicle, there is no better place than in the front of your home. The vehicle was then taken to the good folks at R&J Transmission Service in Waldwick, N.J., where they did a great job taking care of my Uncle’s problem.
I am sure that many of you who are reading this know exactly what happened. The splines for the pump driveshaft inside the torque converter stripped out. This is a fairly common problem, and most torque-converter rebuilding companies install a hardened pump-driveshaft sleeve (Figure 1) into the converter to prevent this from recurring.
A similar problem occurs with Dodge vehicles as early as 1999 with either 3.7L or 4.7L engines. The cause is different from that in the Ford vehicles, but the result is the same: a sudden “going nowhere fast” condition. The cause with Dodge is powdered-metal turbine hubs stripping out. This problem does not occur with the same frequency as the one involving the AX4N’s pump-shaft splines, so the cause is not as quickly identified. In fact, with 45RFE transmissions many times this sudden no-move is blamed on the pump, since it has its own fair share of issues.
The pressed-powder steel turbine hubs are made in such a way that if any engine modifications are made to increase torque the splines will soon strip out. In some instances we see customers who start their vehicles and immediately select drive while idle is high, slamming the engagement. This, too, will eventually take out the hub.
So if a sudden no-move condition should happen to a Dodge vehicle, of course the filter and pump are to be considered, but don’t forget to look inside the converter for stripped turbine splines (figures 2 & 3). Otherwise, once you put the unit back in using the same converter, you too will be going nowhere fast!
