Your transmission may by slipping due to any of these reasons:
A) Low fluid levels.
The most common cause for transmission slipping is low fluid levels. Having low fluid levels can cause problems, such as overheating and not enough hydraulic pressure being produced to engage gears. If you have low fluid levels, add more for the gears to engage properly.
B) Burnt fluid.
This can be discovered by the smell of burnt toast or when the color is black. Burnt fluid occurs due to overheating, and the best way to treat it is by changing the transmission fluid as quickly as possible or have it checked by a mechanic.
C) Transmission fluid leak.
Low fluid levels can also be indicating a transmission fluid leak, whether it’s from ruptured fluid lines, crack in the torque converter, faulty seals, or a leak from the pan, have it sealed immediately to avoid internal damages.
D) Worn or broken transmission bands.
Transmission bands sometimes can become worn or even broken, which can cause transmission slipping, engine troubles and also worn gears. Bands link the gears to the automatic transmission, so worn or broken bands can’t be taken slightly. Get the defective band replaced, adjusted or call your mechanic to look at it.
E) Clutch problems.
Automatic and manual transmissions make use of clutches. In Automatics, clutch plates run throughout the transmission and in the torque converter that may become worn or burnt from low transmission fluid. You will have to get them replaced as quickly as possible and change the fluid. Worn out clutches that have become too thin occur the most, while clutch failures and bad clutch adjustments are rare but do happen.
F) Worn out gears.
Over time gears wears out, due to malfunction or normal wear and tear. Worn or frayed gears may find it difficult linking together properly so get them replaced on time.
The solenoid is an electro-hydraulic valve which controls the flow of fluid throughout your transmission. Any electronic problems or damage can cause the wrong amounts of fluid to be distributed. To check solenoid linked issue, plug a scanner into your car’s computer and if it is, have to fix or replace it.