Test Six-Transmission In Overdrive Fourth Gear
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
This test checks line pressure at the overdrive clutch in fourth gear range. Use 300 psi Test Gauge C-3293-SP for this test. The test should be performed on the road or on a chassis dyno
- Remove tachometer; it is not needed for this test.
- Move 300 psi Gauge to overdrive clutch pressure test port. Then remove other gauge and reinstall test port plug.
- Lower vehicle.
- Turn OD switch on.
- Secure test gauge so it can be viewed from drivers seat.
- Start engine and shift into D range.
- Increase vehicle speed gradually until 3-4 SHIFT occurs and note gauge pressure.
- Pressure should be 469-496 kPa (68-72 psi) with closed throttle and increase to 620-827 kPa (90-120 psi) at 1/2 to 3/4 throttle. Note that pressure can increase to around 896 kPa (130 psi) at full throttle.
- Return to shop or move vehicle off chassis dyno.
PRESSURE TEST ANALYSIS CHART
| TEST CONDITION | INDICATION |
|---|---|
| Line pressure OK during any one test | Pump and regulator valve OK |
| Line pressure OK in R but low in D, 2, 1 | Leakage in rear clutch area (seal rings, clutch seals) |
| Pressure low in D Fourth Gear Range | Overdrive clutch piston seal, or check ball problem |
| Pressure OK in 1, 2 but low in D3 and R | Leakage in front clutch area |
| Pressure OK in 2 but low in R and 1 | Leakage in rear servo |
| Front servo pressure in 2 | Leakage in servo; broken servo ring or cracked servo piston |
| Pressure low in all positions | Clogged filter, stuck regulator valve, worn or faulty pump, low oil level |
| Governor pressure too high at idle speed | Governor pressure solenoid valve system fault. Refer to diagnostic article. |
| Governor pressure low at all mph figures | Faulty governor pressure solenoid, transmission control module, or governor pressure sensor |
| Lubrication pressure low at all throttle positions | Clogged fluid cooler or lines, seal rings leaking, worn pump bushings, pump, clutch retainer, or clogged filter. |
| Line pressure high | Output shaft plugged, sticky regulator valve |
| Line pressure low | Sticky regulator valve, clogged filter, worn pump |