Blocking off or eliminating accumulators to improve shift performance is a common practice. A large hose clamp can be used to align the pump halves when tightening the pump bolts. There is no leaking coming from the front seals, rear sears or oil pan. They are rather expensive, but are still a good idea if they are within your budget, or if you plan to build numerous units. Several companies make threaded-insert kits. Automatic transmissions use pressurized fluid.
A sun gear is the inner most gear in a planetary gear set. A torque wrench is necessary, as each fastener size has a torque value based on its diameter and hardness. Applying these cleaners before power washing or hand cleaning helps to loosen heavy greasy deposits from the case. Some snap ring pliers are also designed to be convertible, and can be modified in seconds to remove either inner or outer snap rings. A hook and pic set comes in handy for transmission rebuiling.
The torque converter provides a coupling between the engine and the transmission. It also works quite well for cleaning internal components. If you look at the list below, it quickly becomes evident that many problems can share a common cause, such as the transmission being low on fluid, or the gear shift selector not moving the manual valve correctly. The early pumps used 6-vane pumps; later designs used 10- and then eventually 13-vane pumps. The drive fan, also called an oil pump or impeller, contains a series of vanes. Shown here is a homemade unit fabricated from square stock and angle iron. The better-quality gloves are thicker and more resistant to solvents such as brake cleaner which works well to remove oily residue from parts before assembly.
Gently clamping the valve body in a shop vise with soft jaws or wooden blocks makes the job even easier. The piston is held away from the clutch pack by springs, often contained in a spring cage that is retained by a snap ring. This provides three separate elements that can be held or driven to provide gear reduction, reverse, or direct drive 1 to 1. The center or sun gear is meshed with planetary gears and is held in a carrier. This is because of the internal design, which is arranged essentially like two fans facing each other. Very early units had a smooth drum and outer race and used a sprag clutch.
Use care for this procedure to avoid damaging the inside of the bore where the bushing is located. It is splined to the turbine and when activated, it is forced against the converter housing. This immediately prevents all slippage between the two parts. An air ratchet and an impact gun speed up the rebuilding process considerably. Flip the block back over and remove the head bolts and separate the heads from the block. This eliminates the potential for a leak at the suction tube or O-ring in the case. Before engine management computers took over transmission shift function, the valve body received signals from several components to help it select the appropriate gear for the driving situation.
This improves its efficiency and torque multiplication. Some bushings are installed below flush for a reason. It also allows for torque multiplication as the engine speed is increased right off idle and as the vehicle accelerates. If a bushing is located in a blind hole, it may be difficult to remove. Heli-Coils and Bolt Extractors The transmissions that I discuss here are cast aluminum alloy. Typically, it unlocks during heavy throttle passing maneuvers, downshifts, and anytime the vehicle is coasting or comes to a stop. Bishop I definitely recommend a look at these transmissions, you've got to have a look.
Roller and sprag clutches also apply very quickly compared to fluid-operated clutch packs or bands. A larger tabletop bench-mounted spring compressor is needed for building clutch drums. The last friction plate has a thick metal backing plate, held in place by a snap ring. Files may be required to remove material from the manual shafts so they can be removed from the case. I also paid very careful attention to the direction in which every part was installed. When it shifts from 1st to 2nd its got a really smooth shift and it puts a smile on your face. Low-vacuum situations, which require heavy- or full-throttle application, such as passing another vehicle, provide a low-vacuum signal to the transmission via the vacuum modulator.
Cases are often coated with mud, dirt, grease, undercoating, and road tar. As the piston moves toward the clutch pack, it contacts an apply plate. Written by Cliff Ruggles and Posted with Permission of CarTechBooks. A razor blade, razor knife, or a small pocket-knife with a very sharp blade comes in handy here. Pressurized oil is routed in behind the piston, which causes it to move and apply force to the clutch pack. You still need to help the seals get past the edges without damaging them.
A shop press works equally as well, although this type of press tends to be much more difficult to set up and a lot slower to use. Hearing protection is also a very good idea. It takes some practice and patience to install lip-type seals without damaging them. A large snap ring is used to hold the backing plate in the drum and to keep it in place when the clutch pack is compressed. Most units use either three- or four-pinion planetary gear sets with helical cut teeth, which further increase tooth contact surface compared to straight cut teeth. One advantage to using bands in a transmission is that they do not take up nearly as much space as a drum and multiple-disc clutch pack. Each section between the vanes provides a small chamber that traps oil as it spins and then forces it out of the pump; it is essentially positive displacement.
The torque converter serves double duty. The unit locks solidly when turned in the opposite direction. This is an area of transmission building that receives considerable attention because several combinations of parts were used, depending on the transmission model and application. Global Transmission Parts is not liable for any errors or omissions. A torque converter clutch is used in most modern torque converters.