An automatic transmission uses fluid to lubricate its internal clutches, gears, and bearings. It incorporates a torque converter as a viscous coupling that uses transmission fluid to transfer engine power to the transmission input shaft. It also uses the fluid under pressure to operate pistons in the valve body and to engage clutches. All this … Read more
The shift cable both pushes and pulls as it operates, so it’s a relatively rigid steel cable in a relatively stiff housing. On an automatic transmission, the shift cable connects from the driver’s shift lever to the shift lever on the transmission. Indications that there might be a shift cable problem would be stiffness or … Read more
The differential receives engine power from the driveshaft and splits the power input between two axle shafts, which drive the wheels on an axle. On a rear-wheel drive, there’s one differential on the rear, and on a four-wheel-drive vehicle, there is a front differential and a rear differential. An all-wheel-drive vehicle is a little different. … Read more
CV axles are most commonly used on the front-wheel-drive vehicles to transfer engine power to the wheels. Some all-wheel-drive vehicles and rear-wheel-drive vehicles with independent rear suspensions also use CV axles to transfer engine power to the wheels. CV axles have an inner joint and an outer joint. Either the two CV joints on a … Read more
Almost all front-wheel drive vehicles use CV axles to transfer engine power from the transaxle to the wheels. An axle seal holds the transmission fluid in at that point where the CV axle splines into the transaxle housing. In addition to keeping oil in, the seal keeps the grit and moisture out. The seal relies … Read more
In an ordinary automatic transmission, the gears are shifted by valves directing the pressurized transmission fluid to engage different hydraulic clutches. On newer car transmission designs, the fluid flow is directed by electric solenoids, which are operated by either the Powertrain Control Module (PCM) or the Transmission Control Module (TCM). On most applications, each solenoid’s … Read more
Most of the time a pinion seal will be replaced when it leaks. Differential fluid is very thick, so a leak will usually begin by a slow seep or dampness around the rear differential housing. If there is wetness or dripping fluid, that is a fairly advanced leak. Most four-wheel-drive vehicles also use a front … Read more
There are two types of slave cylinder. The most common kind is one that is basically a piston in a sleeve which is bolted to the side or top of the transmission where it bears against the clutch fork. Usually, this type is relatively easily accessed, easily replaced, and then, easy to bleed. The other … Read more
The clutch is a crucial part of the drivetrain of any automobile equipped with a manual transmission. It has two main functions: first is to connect and transmit power from the engine to the transmission, and the second is to allow the engine and transmission to be disconnected from one another. This lets the engine … Read more