Is your automatic transmission (auto gearbox) jerking, slipping, shuddering or slow to go into Drive? This checker covers 62 common automatic transmission problems across conventional automatics (AT), CVTs, dual-clutch gearboxes (DCT/DSG) and hybrids. For each one you get the likely cause, the quick check to do first, how urgent it is, and whether KM+ AT Fix-IT can fix it without opening the gearbox.
Most gearbox complaints start the same way: rubber seals in the hydraulic control system harden with age and heat, pressure leaks away, and the clutches slip, shudder or engage late. That is why 37 of the 62 problems are marked as fixable with AT Fix-IT.
Find your transmission symptom
Type what your car is doing, or tap a group to browse. Cards marked ✔ Fix-IT fixes this are problems KM+ AT Fix-IT can usually fix, once the quick check on the card passes.
Slow to engage Drive or Reverse
6 of 8 fixable
Why: Hardened seals let pressure leak back while the car is parked; the gearbox needs time to refill
Check first: Fluid level; does the delay disappear once the car is warm?
What to do: Use KM+ AT Fix-IT. The classic seal-hardening sign and the best match for AT Fix-IT.
Why: Same pressure loss in the reverse circuit
Check first: Fluid level; compare with Drive
What to do: Use KM+ AT Fix-IT. Usually improves together with Drive.
Why: Hot fluid is thinner, so worn seals leak more
Check first: Fluid level and smell when hot
What to do: Use KM+ AT Fix-IT if the fluid is not burnt.
Why: Pressure builds late, then the clutch grabs suddenly
Check first: Engine and gearbox mounts (have someone watch the engine as you select D and R); fluid
What to do: Use KM+ AT Fix-IT once worn mounts are ruled out.
Why: Hardened seals leaking pressure: the classic sign of advanced seal hardening
Check first: Fluid level is correct; no warning lights
What to do: Use KM+ AT Fix-IT. Restores the lost pressure so the car moves off normally again.
Why: The seals in that one clutch circuit have hardened and leak so much the clutch cannot close. Heat softens them, so it works when hot
Check first: Fluid level; no warning lights; it does move once hot
What to do: Use KM+ AT Fix-IT. Restores the seals so the clutch closes when cold again.
Why: Broken drive shaft, failed oil pump, broken internal part or selector fault
Check first: Drive shafts; selector cable; fluid level
What to do: Workshop. Not an additive problem.
Why: Wrong fluid, wrong level or a fitting problem from the service
Check first: Fluid type and level; filter seal
What to do: Return to the workshop that did the service.
Transmission slipping: revs rise but the car does not pull
6 of 10 fixable
Why: Pressure drops during the shift because seals no longer hold it
Check first: Fluid level and smell; scan for codes
What to do: Use KM+ AT Fix-IT. A typical AT Fix-IT case.
Why: Heat thins the fluid and exposes leaking seals
Check first: Fluid smell (burnt?); radiator and cooling fan working
What to do: Use KM+ AT Fix-IT if the fluid is not burnt and there is no temperature warning.
Why: Cold, hard seals that soften as the gearbox warms up
Check first: Fluid level
What to do: Use KM+ AT Fix-IT. A strong match for AT Fix-IT.
Why: Severe pressure loss from hardened seals: the clutches can no longer be pressed hard enough to hold
Check first: Fluid level; no warning lights; no grinding
What to do: Use KM+ AT Fix-IT. Proven even in severe cases: see our Toyota Alphard case below.
Why: Hardened seals in the clutch circuit for that one gear leak pressure
Check first: No warning lights or fault codes
What to do: Use KM+ AT Fix-IT. Restores pressure in that clutch circuit so the gear holds again.
Why: Low pressure from hardened seals lets the clutches slip. Slipping creates heat, which burns and oxidises the fluid quickly
Check first: No metal particles or heavy debris in the fluid; no warning lights
What to do: Use KM+ AT Fix-IT. Restores the pressure so the slipping, and the overheating, stop. Change the burnt fluid soon after, then use KM+ Nano ATF Treatment.
Why: Low fluid, or the oil pump losing pressure when hot
Check first: Fluid level when hot
What to do: If the fluid level is correct, AT Fix-IT can stop the slip. If the whine stays afterwards, have the pump checked.
Why: Low fluid: the oil pick-up sucks air in corners
Check first: Fluid level; look for leaks
What to do: Top up and fix the leak first. Use AT Fix-IT only if it still slips with the level correct.
Why: Long-term slipping from low pressure has worn the clutch packs and shed debris
Check first: Workshop inspection: confirm no broken parts and that the clutches still have lining
What to do: Check first. If nothing is broken, AT Fix-IT can restore pressure and stop the slip. Our own Alphard had wear particles in its fluid before its first treatment. Change fluid and filter afterwards.
Why: Major pressure loss, overheating or a control fault
Check first: Fault codes; fluid
What to do: Workshop. A safety risk in traffic.
At 200,000 km it slipped so badly it could not climb a 5% slope. One bottle of KM+ AT Fix-IT solved it. Two more treatments in 2022 and 2026 kept it going: at 345,000 km it now climbs a 15% slope with ease. Three treatments in seven years, 145,000 km of extra driving.
Rough, jerky or late gear changes (harsh shifting)
12 of 14 fixable
Why: Uneven clutch pressure from aged seals and tired fluid
Check first: Scan for codes; fluid; engine mounts
What to do: Use KM+ AT Fix-IT.
Why: Hard seals and thick cold fluid
Check first: Fluid age
What to do: Use KM+ AT Fix-IT. A strong match.
Why: Hot fluid is thinner, so hardened seals leak more and clutches apply unevenly
Check first: Fluid not burnt; no fault codes
What to do: Use KM+ AT Fix-IT. Restores pressure so shifts stay smooth when hot.
Why: Heat thins the fluid; leaking seals can no longer hold enough pressure to complete the shift
Check first: No fault codes (a heat-sensitive sensor can do the same); fluid level
What to do: Use KM+ AT Fix-IT. Restores the pressure needed to complete the shift when hot.
Why: Clutch pressure is not held evenly at every throttle level because seals leak
Check first: No throttle or sensor codes
What to do: Use KM+ AT Fix-IT. Restores even pressure across all throttle levels.
Why: The lower gear's clutch cannot apply firmly enough, so the gearbox stays in the higher gear
Check first: No sensor codes and not in limp mode
What to do: Use KM+ AT Fix-IT. Restores pressure so the downshift can complete.
Why: Pressure control at low speed is uneven
Check first: Fluid; codes
What to do: Use KM+ AT Fix-IT. Common in city cars, taxis and e-hailing cars.
Why: Pressure builds slowly, so the shift comes late
Check first: Fluid; codes
What to do: Use KM+ AT Fix-IT if there are no fault codes.
Why: Hardened seals in the clutch circuit for that one gear leak pressure, so that clutch applies late and then grabs
Check first: No warning lights or fault codes (a failed solenoid can cause the same symptom)
What to do: Use KM+ AT Fix-IT. Restores pressure in that clutch circuit so the shift is smooth again.
Why: A gear change cannot complete because its clutch slips from lost pressure, so the computer locks the gearbox in a safe gear
Check first: Fault-code scan before clearing anything: confirm it is a ratio, slip or pressure code, not a circuit or sensor code
What to do: Use KM+ AT Fix-IT. Restores the pressure so the shift completes. Clear the code after treatment.
Why: A clutch slipping from lost pressure: the computer sees the slip and keeps searching for another gear
Check first: No sensor or circuit codes (a faulty throttle or speed sensor can cause the same symptom)
What to do: Use KM+ AT Fix-IT. Restores pressure so each gear holds and the hunting stops.
Why: The clutch for D or R applies late and then grabs hard because pressure builds slowly
Check first: Engine and gearbox mounts are OK (watch the engine as someone selects D and R with the brake held)
What to do: Use KM+ AT Fix-IT. Smooths the engagement once worn mounts are ruled out.
Why: An electrical fault in the gearbox control system
Check first: Fault-code scan; battery and connectors
What to do: Workshop. Electrical faults cannot be fixed by an additive.
Why: The gearbox computer lost its learned settings
Check first: Battery connections; relearn procedure
What to do: Ask the workshop to do a gearbox relearn.
Shudder, judder, shaking and vibration
3 of 6 fixable
Why: The torque converter lock-up clutch is grabbing unevenly
Check first: Tap the brake lightly: if the shudder stops instantly, it is the lock-up clutch
What to do: Use KM+ AT Fix-IT. A typical AT Fix-IT case (if the fluid is not burnt).
Why: Uneven clutch apply from lost pressure
Check first: Fluid; codes
What to do: Use KM+ AT Fix-IT.
Why: The take-off clutch or torque converter grabs unevenly because pressure is low
Check first: CV joint rubber boots intact; engine mounts OK
What to do: Use KM+ AT Fix-IT. Restores even clutch pressure for a smooth take-off.
Why: Worn inner CV joint (drive shaft)
Check first: CV joint rubber boots for tears or thrown grease; clicking on full lock
What to do: Workshop: replace the drive shaft or CV joint.
Why: Worn engine mounts or a rough-idling engine
Check first: Mounts; engine idle speed
What to do: Mounts or an engine tune-up. KM+ Decarbonizer may help a carbon-fouled engine.
Why: Engine misfire
Check first: Scan engine codes
What to do: Engine repair first.
CVT gearboxes
4 of 5 fixable
Why: Loss of pressure control and tired CVT fluid
Check first: Correct CVT fluid type; CV joints
What to do: Use KM+ AT Fix-IT.
Why: The belt is not being clamped firmly enough
Check first: Fluid level and type; no whining noise
What to do: Use KM+ AT Fix-IT when mild and quiet.
Why: Low clamping pressure lets the belt slip on the pulleys, so the ratio keeps correcting itself
Check first: No circuit or sensor codes
What to do: Use KM+ AT Fix-IT. Restores clamping pressure so the belt holds steady.
Why: Belt slip from low clamping pressure creates heat inside the CVT
Check first: CVT cooler and radiator fan working; fluid not long overdue
What to do: Use KM+ AT Fix-IT. Stops the slip that creates the heat. Then change to KM+ CVT Fully Synthetic Fluid and use Nano CVT Treatment for care.
Why: Bearing, pump or belt wear
Check first: Fluid level
What to do: Workshop.
Read more: CVT shudder or judder: causes and fixes
Dual clutch (DCT/DSG) and hybrid cars
3 of 5 fixable
Why: Clutch pressure loss
Check first: Confirm it is a wet-clutch gearbox
What to do: Use KM+ AT Fix-IT.
Why: The mechatronic unit shifts gears with its own small hydraulic circuit; aged seals there lose pressure
Check first: Workshop check: rule out a cracked accumulator housing or a failed pump motor
What to do: Use KM+ AT Fix-IT. Workshop-applied: 50 ml of AT Fix-IT added to the mechatronic hydraulic oil (not the gearbox oil).
Why: The engine clutch or gearbox is losing pressure
Check first: Hybrid warning lights (none should be on)
What to do: Use KM+ AT Fix-IT.
Why: Clutches and gear changes are worked by electric motors, not oil pressure
Check first: Ask your workshop which gearbox you have
What to do: AT Fix-IT is not suitable: there is no hydraulic pressure to restore. Use KM+ Nano ATF Treatment for gearbox-oil maintenance.
Why: No clutch packs or gear changes in the usual sense
Check first: Jerking here is usually engine or hybrid-system related
What to do: AT Fix-IT is not needed. Workshop check.
Leaks and fluid condition
2 of 8 fixable
Why: Aged rubber seals that have hardened and shrunk
Check first: Clean the area and find where the wetness starts
What to do: Use KM+ AT Fix-IT. AT Fix-IT restores seal elasticity. It is not a stop-leak.
Why: The gearbox front seal (around the torque converter) has hardened and shrunk
Check first: Confirm it is gearbox fluid (red/brown, sweetish smell), not engine oil; a seep, not a steady drip
What to do: Use KM+ AT Fix-IT. Restores the front seal's elasticity. AT Fix-IT is a seal revitaliser, not a stop-leak.
Why: Cracked cooler line, loose fitting or badly damaged seal
Check first: Trace the leak to its highest wet point
What to do: Workshop repair.
Why: The engine's flywheel oil seal (crankshaft rear seal) has hardened and leaks. This is an engine leak, not the gearbox
Check first: Oil colour and smell; engine oil level
What to do: Use KM+ Engine Fix-IT, our separate engine-leak treatment, added to the engine oil to stop the leak. (AT Fix-IT is for the gearbox only.)
Why: Impact damage, or past severe overheating
Check first: Visual inspection
What to do: Workshop repair. AT Fix-IT cannot seal a crack.
Why: An active leak somewhere
Check first: Find the leak
What to do: Fix the leak, then treat if symptoms remain.
Why: Past overheating or very old fluid
Check first: Cooling system; service history
What to do: Fluid change, then KM+ Nano ATF Treatment for ongoing care.
Why: Overfilled, or coolant mixing into the fluid
Check first: Fluid level; radiator cooler
What to do: Workshop.
Noises, warning lights and other signs
1 of 6 fixable
Why: Hydraulic leaks from hardened seals let the clutches (AT) or belt (CVT) slip, and the slipping generates heat
Check first: Radiator fan, radiator and gearbox cooler lines working; fluid level correct
What to do: Use KM+ AT Fix-IT. Stops the slip that creates the heat. Change the fluid afterwards, as overheated fluid wears out faster.
Why: Low fluid, pump or bearing wear
Check first: Fluid level
What to do: Top up if low; otherwise workshop.
Why: Broken or damaged internal parts (bearings, gears, pump)
Check first: Look for metal in the fluid
What to do: Workshop. An additive cannot repair broken parts.
Why: Cracked flexplate (between engine and gearbox), worn mounts or a loose heat shield
Check first: Listen at the joint between engine and gearbox
What to do: Workshop.
Why: Selector cable, range switch, shift interlock or parking lock
Check first: Selector position vs gear display
What to do: Workshop.
Why: Engine idle problem or a stuck converter clutch
Check first: Idle speed; engine codes
What to do: Engine check. KM+ Decarbonizer or Injector Cleaner may help a carbon-related idle problem.
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General guidance only; it does not replace an inspection by a qualified mechanic.
Cars and gearboxes we see most often
Whether you call it a transmission, a gearbox, an auto gearbox or a kotak gear, the checker covers the automatic types fitted to most cars on Malaysian roads:
- Conventional automatic (AT, with a torque converter): Perodua Axia, Bezza and Myvi (4-speed auto), Proton Saga and Persona, Toyota Camry, Mazda models, VW Polo and many older Japanese and Continental cars.
- CVT: Honda City, Civic and HR-V, Toyota Vios and Corolla Cross, Nissan Almera, Perodua Alza and Ativa, and the newer Myvi and Axia with D-CVT.
- Dual clutch (DCT/DSG): Proton X50 and X70 (7-speed wet dual clutch), VW Golf and Jetta 1.4 TSI (7-speed dry DSG), and VW and Audi 2.0 models with a wet DSG.
- Hybrids: hybrid cars that use a normal automatic, a CVT or a wet dual clutch.
Common complaints we hear include a Myvi or Axia jerking when cold, Honda City or Vios CVT shudder at low speed, Proton X70 dual clutch judder when pulling away, RPM flaring between gears, and vibration at idle in Drive. Type yours into the search box above.
The fix for the blue cards
KM+ AT Fix-IT
Restores lost pressure in the gearbox’s hydraulic control system without opening the gearbox. One 150 ml bottle per 4–6 L of fluid. For AT, CVT, wet-clutch DCT/DSG and hybrids.