What is "gears not shifting smoothly"?
With a good car, you should be able to shift gears smoothly without feeling any unusual resistance, grinding noises, or jerking.
If you notice:
- Resistance shifting
- Grounding or clunking
- Delay before the gear engages
- Gears slipping when driving
This suggests that there is likely an issue with the transmission system, clutch, or a related component. Failure to treat it can cause the problem to worsen and lead to costly repairs.
Common causes of gears not shifting smoothly
There are several reasons why your car's gears might be stiff or rough.
1. Low or dirty transmission fluid
Transmission fluid allows the gears to move smoothly. When the fluid becomes low, old, or dirty, the gears may stick or fail to shift.
Symptoms:
• Hard or jerky shifting
• Transmission heat
• Burning transmission odour
Repair:
• Inspect transmission fluid level and refill if necessary
• Change old or dirty fluid according to the manufacturer's guide
• Always use the same kind of fluid your car was originally equipped with
2. Worn clutch (for manual vehicles)
Clutch enables smooth engagement and disengagement of gears. A worn clutch plate, pressure plate, or release bearing will make it difficult to shift gears.
Symptoms:
• Gear grinding on shifting
• The car jerks forward when shifting into a gear
• Clutch pedal is stiff or spongy
Fix:
• Check the clutch parts
• Replace damaged clutch plates, release bearing, or pressure plate
• Adjust clutch pedal if necessary
3. Clutch not fully disengaging
If the clutch will not disengage completely, the gears can fight engagement. This is usually due to hydraulic problems, air in the clutch lines, or an improperly adjusted clutch cable.
Symptoms:
• Finding difficulty with the first or reverse gear
• Grinding or dragging when shifting gears
Repair:
• Bleed the clutch system to drain air
• Adjust clutch cable to normal free play
• Diagnose and fix or replace defective hydraulic parts
4. Worn or damaged synchronisers (manual transmission)
Synchronisers assist in bringing gears into synchronisation for easy engagement. When synchronisers are worn, the gear will grind or clash during shifting.
Symptoms:
• Grinding sound during gear changing
• Gears jerk out of position
• Hard shifting at high speeds
Repair:
• Renew or replace worn synchronisers
• Inspect the gearbox for other internal wear
5. Transmission linkage problems
The linkage is the rod that joins the gear lever to the transmission. If it is worn, loose, or out of place, the gear lever will not move smoothly.
Symptoms:
• Gear lever feels loose or stiff
• Cannot engage some gears with ease
• Gear shifts are inaccurate
Repair:
• Check the gear linkage for misalignment or wear
• Replace worn linkage pieces or bushings
• Lubricate the moving parts for smooth shifting
6. Damaged or worn gearbox
Worn-out gears, bearings, or shafts in a gearbox may make shifting hard. This is most often caused by a lack of maintenance, overheating, or long-term use of low-quality transmission fluid.
Symptoms:
• Grinding or knocking noises from the gearbox
• Gear slipping when driving
• Vibration when shifting gears
Solution:
• Have the gearbox checked by a professional
• Replace blown-up gears or bearings
• In extreme cases, a rebuild or replacement of the gearbox might be necessary
7. Incorrect use of gears and driving habits
Using the wrong gear for speed, riding the clutch, or aggressive shifting can lead to temporary trouble shifting gears and eventual wear.
Symptoms:
• Gears become hard to shift after aggressive driving
• Clutch wears out quicker
Solution:
• Use proper gear according to speed and road conditions
• Don't rest your foot on the clutch while driving
• Shift gears smoothly but not forcefully
8. Automatic transmission problems
For automatic cars, jerky or slow gear changes could be due to:
• Low or dirty transmission fluid
• Faulty solenoids
• Worn-out torque converter
• Transmission control module (TCM) faults
Symptoms:
• Jerky gear changes
• Transmission warning light on dashboard
• Unusual noises when accelerating
Fix:
• Check and change transmission fluid
• Check solenoids and torque converter
• Reset or fix TCM if necessary
9. Issues with the engine or sensors
Occasionally, engine or sensor malfunctions, such as throttle position sensor (TPS) or speed sensor faults, may cause trouble shifting gears, particularly in automatic cars.
Symptoms:
• Shabby gear shifts
• Transmission warning light
• Poor acceleration
Solution:
• Check sensor problems with a scan tool
• Replace malfunctioning sensors
• Make the engine run smoothly
10. Cold or dirty oil
In manual and automatic transmissions, old, thick, or dirty transmission oil can cause a loss of smoothness during gear engagement.
Symptoms:
• Sticky or stiff gear lever
• Harsh cold-start shifts
Solution:
• Flush out the transmission fluid
• Replace with new, manufacturer-specified fluid
How to check if the gears are not shifting smoothly
You can do some simple tests before visiting a mechanic:
1. Manual car: Try shifting through all gears with the engine running and the clutch fully depressed. Note any resistance or grinding.
2. Automatic car: Observe the gear changes while driving at normal speeds. Note delays, jerks, or vibrations.
3. Check the fluid: Look at the transmission fluid level and condition.
4. Pedal feel: In a manual car, press the clutch and check if it feels soft, stiff, or spongy.
If you notice unusual resistance, grinding, or slipping, get your car inspected by a professional. No matter what the issue is, whether your gears feel rough or hard to shift, our ACKO Drive service centres can help. We inspect the clutch, gearbox, and transmission fluid for faults. After servicing, your car will shift smoothly and perform better.
You can book a service slot online through the ACKO app or the ACKO Drive website. We offer free pick-up and drop-off, share diagnostic reports online, and you can also track the service online without the need to visit the service centre.
Some risks of ignoring gear shifting problems
Driving with hard or tough gear shifts can result in major issues:
• Damage to the clutch or transmission
• Increased fuel usage
• Jerky or dangerous driving, particularly in traffic
• Total transmission failure in worst-case scenarios
Early repair saves money and prevents further damage.
How to repair gears that do not shift smoothly
Repairing this problem varies based on the underlying cause. A mechanic can:
• Inspect and replace transmission fluid
• Check and repair the clutch or clutch hydraulic system
• Adjust or replace gear linkage
• Fix or replace synchronisers, gears, or bearings
• Check sensors and electronic parts in automatic vehicles
• Replace worn-out or damaged parts with original components
Regular maintenance and prompt repair guarantee smooth, safe gear shifting.
Final words
If your car’s gears are not shifting smoothly, then it means that something in the transmission, clutch, or linkage needs attention. Ignoring the problem can lead to costly repairs and unsafe driving conditions.
Have your car checked by a reliable mechanic as soon as possible. Proper maintenance, proper driving techniques, and on-time replacement of deteriorated parts will ensure your gear shift remains smooth, secure, and comfortable.
Frequently asked questions
