Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

Other materials:

Mazda 6 Service Manual: Automatic transaxle fluid (atf) inspection
Automatic Transaxle Fluid (ATF) Condition Inspection One way of determining whether the transaxle should be disassembled is by noting: If the ATF is muddy or varnished. If the ATF smells strange or unusual. ATF Condition Automatic Transaxle Fluid (ATF) Level Inspection Caution Th ...

Mazda 6 Service Manual: Precautions before welding
Vehicles have various electrical parts. To protect the parts from excessive current generated when welding, be sure to perform the following procedure. 1. Turn the ignition switch to the LOCK position. 2. Disconnect the battery cables. 3. Securely connect the welding machine to the ground nea ...