Possible reasons for reverse gear slipping if you have an automatic transmission:
Transmission fluid problems:
*Low fluid level
* Contaminated liquid
* Wrong fluid type
Solenoid problems:
* Faulty reverse solenoid
* Dirty or clogged solenoid passages
Problems with torque converter:
* Worn or damaged seat ring
* Defective torque converter lock-up clutch
Problems with mechanical components:
* Worn reverse gears
*Damaged reverse drum
* Slip friction lining
Other possible reasons:
* Faulty transmission switch
* Electrical faults in the wiring harness
*Transmission control module (TCM) software problems
Diagnostics:
To diagnose the problem, you will need the following steps:
* Checking the level and condition of the transmission fluid
* Scan trouble codes using diagnostic scanner
*Physical inspection and testing of transmission components
Repair:
Depending on the cause of the reverse gear slipping, the following repair work may be required:
* Replacing or topping up transmission fluid
* Replacement of solenoids
* Repair or replacement of torque converter
* Replacement of gears or other mechanical components
* Repair or replacement of electrical components
* TCM software update
Tips for use:
* Check the level and condition of the transmission fluid regularly.
*Follow the manufacturer’s recommended fluid and filter change schedule.
* Avoid driving the vehicle under high stress conditions, such as steep inclines or towing heavy loads.
*If you notice any problems with reverse gear shifting, take it to a qualified mechanic as soon as possible.