Road Test
Prior to performing a road test, verify that the fluid level, fluid condition, and linkage adjustment is correct.
During the road test, the transmission should be operated in each position to check for slipping and any variation in shifting.
If the vehicle operates properly at highway speeds, but has poor acceleration, the converter stator overrunning clutch may be slipping. If acceleration is normal, but high throttle opening is needed to maintain highway speeds, the converter stator clutch may have seized. Both of these stator defects require replacement of the torque converter and thorough transmission cleaning.
Slipping clutches can be isolated by comparing the "Elements in Use" chart with clutch operation encountered on a road test. This chart identifies which clutches are applied at each position of the selector lever.
A slipping clutch may also set a Diagnostic Trouble Code (DTC) and can be determined by operating the transmission in all selector positions.
| 948TE 9 Speed Planetary Automatic Transmission with 6 shift elements and 4 planetary gear sets. | ||||||||
| CLUTCH-A | CLUTCH-B | CLUTCH-C | CLUTCH-D | CLUTCH-E | CLUTCH-F | RATIO | ||
| GEAR | 1st | X | X | X | 4.70:1 | |||
| GEAR | 2nd | X | X | X | 2.84:1 | |||
| GEAR | 3rd | X | X | X | 1.90:1 | |||
| GEAR | 4th | X | X | X | 1.38:1 | |||
| GEAR | 5th | X | X | X | 1.00:1 | |||
| GEAR | 6th | X | X | X | 0.80:1 | |||
| GEAR | 7th | X | X | X | 0.69:1 | |||
| GEAR | 8th | X | X | X | 0.58:1 | |||
| GEAR | 9th | X | X | X | 0.47:1 | |||
| GEAR | N/P | X | X | - | ||||
| GEAR | R | X | X | X | 3.81:1 | |||