There are several possible reasons why an automatic transmission may start to kick:
Low transmission fluid level:
*Low fluid levels can cause gears to slip and vibrate.
Contaminated transmission fluid:
*Dirty fluid contains particles and sediment that can clog filters and prevent the transmission from operating smoothly.
Wear of friction discs and bands:
* With age, friction materials wear out, resulting in gear slippage and speed fluctuations.
Clogged oil filter:
* A clogged filter restricts fluid flow, which can cause pressure build-up and shifting shock.
Faulty solenoids:
* Solenoids control gear shifting and malfunctioning solenoids can result in harsh shifts and bumps.
Faulty hydraulic plate:
* The hydraulic plate directs pressurized fluid to transmission components and a malfunction can cause improper pressure and shock loads.
Electrical wiring problems:
* Faulty wiring can cause signal problems between the transmission control module and the solenoids, causing knocking.
Faulty transmission control module:
* The transmission control module controls gear shifts and a malfunction can result in random shifts and knocking.
Weak torque converter clutch springs:
*Weak springs can cause the torque converter to slip and shift shock.
Improper maintenance:
* Failure to replace fluid and filter promptly can result in sludge buildup and component wear, causing shock.