Vehicle automatic transmissions have come a long way since the first mass-market transmissions were introduced in the early 1950s. Onboard computer systems regulate upshifting and downshifting, torque and a host of other systems that give the transmission a long, dependable life. Common problems with automatics usually stem from owner neglect and abuse, with overheating, lack of scheduled maintenance and work too stressful for the make and model of the vehicle.
A leaking fluid line will cause an automatic transmission to slip when shifting into a high gear. This means that the tube is sucking air. A slipping transmission may also be the result of a clogged filter. Remove the transmission pan to determine how much material, shavings, dirt, grit, etc., is inside and determine whether any damage has occurred. At the same time, replace the filter.
Hard, clunky shifting in automatic transmissions is another common problem. Some transmissions are naturally clunky. Some of the BMW M-Series sports coupes are notorious for inelegant shifting. But for the average passenger car and truck, the automatic should shift seamlessly from gear to gear. Hard shifting may be a result of a factory-installed high-stall converter, which makes hard shifting a normal occurrence. But it's more likely due to a dirty filter.
Owners should not to confuse transmission problems with differential damage. Jerking and stopping or even having the vehicle lock up in Neutral may not be a transmission problem at all. Instead, it's more likely the shaft linking the transmission to the differential may have come loose. It's not expensive to repair.
Chrysler manufactures its own transmission fluid and requires that it be used for servicing its transmissions. By filling Dodge trucks and SUV automatics with a 4WD transfer case with a non-Chrysler fluid, the vehicle may lose power or fail to shift into gear. The wrong fluid should be flushed and replaced with Chrysler's ATF+3 fluids, according to allpar.com.
Burned fluid can cause automatic transmission failure. Pull the transmission fluid dipstick. If the pink fluid smells like burned toast or has a brownish appearance, the fluid has been overheated and no longer effective as a lubricant. If caught early, the transmission may have escaped damage. The fluid should be changed immediately, according to aa1car.com.
Pre-2001 Dodges may experience stalling and hard shifting when performing heavy-duty pulling or snow plowing due to the torque converter clutch engaging improperly. New computer software should be installed to improve engine torque.
Some late-model V-8-powered Fords with automatic transmission may experience selector problems in which the gearbox may only operate in fourth gear. If the shifter is moved to Reverse, the transmission may shift hard and jerk the vehicle. This is likely due to a faulty shift solenoid. In the General Motors TH700R4 automatic transmission, an improperly installed throttle valve cable can make the transmission shift improperly, according to purplesagetradingpost.com and freeengineinfo.com.
