
The shift pattern of the transaxle is conventional, as shown.
Depress the clutch pedal all the way down while shifting; then release it slowly.
Your vehicle is equipped with a device to prevent shifting to R (reverse) by mistake. Push the shift lever downward and shift to R.

WARNING
Do not use sudden engine braking on slippery road surfaces or at high speeds:
Shifting down while driving on wet, snowy, or frozen roads, or while driving at high speeds causes sudden engine braking, which is dangerous. The sudden change in tire speed could cause the tires to skid. This could lead to loss of vehicle control and an accident.
Always leave the shift lever in 1 or R position and set the parking brake when leaving the vehicle unattended:
Otherwise the vehicle could move and cause an accident.
CAUTION
NOTE
If shifting to R is difficult, shift back into neutral, release the clutch pedal, and try again.
Gear Shift Indicator (GSI)Mazda 6 Owners Manual: Clutch master cylinder disassembly/assembly
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
Snap Ring Disassembly/Assembly Note
Hold the piston down using a cloth-wrapped pin punch.
If disassembling, remove the snap ring; if assembling, install it.
...
Mazda 6 Owners Manual: Oil leakage inspection
Use either of the following procedures to identify the type of oil that
is leaking:
Using UV Light (Black Light)
1. Remove on the engine or transaxle.
Note
Referring to the fluorescent dye instruction manual, mix the
specified amount of dye into the engine oil or ATF (or transaxle ...