An automatic transmission is a mingled quantity of system with many little disks (clutches and steels) contained in larger cylinders forming clutch packs. The transmission uses both hydraulic fluid and electronics to control these clutch packs. When an automatic transmission goes bad, it doesn't need to be replaced---instead, it can be rebuilt. This rebuilding process requires some common tools and a few more-specific tools that the average mechanic may not have.
They come in many different sizes to fit the variety of bolt and nut sizes available.
Torque Wrench
A torque wrench is similar to a ratchet but is used only to tighten bolts.Socket Set
The socket is placed on the end of the ratchet and fits a nut or bolt. Sockets are small, cylindrical metal pieces that are hollow inside to allow a nut or bolt to be inserted.
Ratchet Set
The ratchet is a common tool that nearly every mechanic has. This device, used in conjunction with a socket to remove nuts and bolts, is a long metal rod with a ratcheting head to hold the socket. The ratcheting head functions so that the mechanic can reset the wrench without having to remove the tool from the nut or bolt.The other main difference is that it has an adjustable dial to select the proper torque amount for the particular bolt you're tightening; the wrench will emit an audible sound, typically a click, when it reaches the set torque value. This feature assures that bolts are not over- or under-torque, which is especially important when rebuilding a transmission.
Snap-Ring Pliers
Snap-ring pliers are a set of pliers that are used for opening instead of closing. The pliers have small pins on the ends that are inserted into the holes on a snap ring; the device is then opened to free the snap ring from the groove it sits in. This procedure is required when you're rebuilding a transmission, as the clutch packs are held together by these snap rings.
O-Ring Hook
The O-ring hook is a metal hook designed to pull an O-ring from the groove it sits in. An O-ring is a small rubber gasket that's in an "O" shape to create a seal. This is a must in all transmission rebuilds, as there are as many as 10 O-rings to be replaced in a rebuild.
Washer
A washer is between 3 to 5 feet tall and about 3 feet wide, depending on the model. It has a metal door on the front to place parts in for cleaning. Cleaning the transmission case and all of the reused hard parts is a requirement, as transmission failure may lead to metal shavings being spread throughout the internals of a transmission; failure to clean out these shavings can lead to transmission failure after the rebuild is completed. This washing ensures that all of the debris is cleaned out; it also makes all of the parts look new again.
Rebuilding Bench
The bench used is nearly as important as the tools used to disassemble the transmission. This type of bench has a slight slope so that all of the transmission fluid runs away from the mechanic and into a trough for proper disposal. This bench has different slots for all of the common tools used during a rebuild, including hooks so that the mechanic can hang small parts for reuse, as well as straps to hold the transmission in place during the rebuild.
Transmission Jack
The transmission jack is used to lower the transmission during removal and to lift it to reinstall it. This jack is about 3 feet tall and has a plate on top for the transmission to sit on and a series of ratcheting straps to secure the transmission.
