4-speed automatic thump and slip
Book a workshop soon. You do not need to stop driving today.
If ignored: Left alone, the flare and shudder stay and the next quote is a rebuild.
Affects model years: 2004-2008
Symptoms
- Hard thump when shifting from Park or Reverse into Drive
- Delay before the car moves when you press the accelerator
- Flare in revs between the 1-2 and 2-3 shifts
- Shudder under light throttle at low speed
Cause
The four-speed automatic's fluid and clutches wear with heat and age. A car that has towed, sat in traffic for 200,000 km or missed its fluid changes will show it first as a delayed engagement, then as a flare between gears. Old fluid turns the shifts harsh before the gearbox actually fails.
Solution
Ask a workshop to check the fluid condition and change it with the correct Proton automatic transmission fluid, then drive the car again. A fluid and filter service is the cheap attempt and sometimes restores the shift. If the flare or shudder stays, get a quote for a rebuild before spending on anything else, because a rebuild is a four-figure bill on a car worth less than that.
fitted · as of Oct 26, 2026
The manual Gen-2 avoids this entire problem, and that is the main reason to prefer one if you have the choice. If you need the automatic, drive it cold. A warmed-up gearbox hides a delayed engagement, and the delay is the earliest symptom.
On the test drive, shift from Park to Drive with your foot on the brake and count. Anything more than a moment, or a jolt you feel through the seat, is a car you should price as needing a gearbox service at minimum.
Do not accept “they all do that”. A tired 4AT does that; a healthy one engages cleanly. The difference is a fluid service and, eventually, a rebuild.
Cost band checked 2026-10-26 against Malaysian workshop pricing for a 4AT fluid and filter service; a rebuild quote is a separate four-figure conversation.
Community notes
Lowyat.NET Gen-2 threads describe delayed Drive engagement and harsh shifts on high-mileage autos, and the same 4AT family appears in the Proton Saga of the era.