OBJECTIVES

2. OBJECTIVES After studying Chapter 16, the reader should be able to: • Describe the automatic transmission overhaul procedures. • Perform the automatic transmission disassembly inspection procedure. • Properly disassemble and reassemble an automatic transmission. • Complete the ASE tasks related to off-vehicle transmission/transaxle repair.

3. INTRODUCTION • A badly worn or damaged transmission is removed from the vehicle for repair, and there are essentially four repair choices: • Repair or replace the worn/damaged component, • Overhaul the transmission • Replace the transmission with an exchange/used • Install a remanufactured transmission. • When the overhaul is done by a technician working at an automotive repair facility, it will be guaranteed by the shop.

4. INTRODUCTION • Overhauled Transmissions • Remanufactured Transmissions • Transmission Parts • Overhaul Procedure • To overhaul or rebuild an automatic transmission, you should:

5. FIGURE 16-1 A remanufacturing assembly line. The valve bodies are moving from left to right as they are being assembled; the computer identifies which parts are to be installed and their location (a). The transmissions also move along an assembly line; each station has a monitor to show the operation, the parts to be installed, and the special tools to install them (b). (Courtesy of Williams Technologies Inc., Div. of Delco Remy International, Inc.) INTRODUCTION

6. FIGURE 16-2 Aftermarket sources can provide most of the parts needed to repair a transmission as well as supplemental parts and information. (Courtesy of Slauson Transmission Parts,www.slauson.com) INTRODUCTION

7. FIGURE 16-3 The soft parts required to rebuild a transmission are available as kits. The contents of a kit will vary with different suppliers. INTRODUCTION

8. FIGURE 16-4 These special tools are used when rebuilding a THM 350. (Courtesy of ATEC Trans-Tool and Cleaning Systems) TRANSMISSION DISASSEMBLY • The disassembly procedure for a transmission varies between makes and models. • Special tooling or procedures are often required.

9. FIGURE 16-4 (CONTINUED) These special tools are used when rebuilding a THM 350. (Courtesy of ATEC Trans-Tool and Cleaning Systems) TRANSMISSION DISASSEMBLY

10. FIGURE 16-5 This transmission is being cleaned using a hot, highpressure washer. A thorough cleaning makes it easier to locate and remove bolts and retaining rings and keeps the work area cleaner. TRANSMISSION DISASSEMBLY • Predisassembly Cleanup • Cleanliness is a must during a transmission overhaul. • Many shops steam clean or pressure wash the outside of the transmission as soon as it is removed from the vehicle.

11. TRANSMISSION DISASSEMBLY • Torque Converter Removal • The converter is removed from the vehicle with the transmission. • It is then removed from the transmission by sliding it out the front of the transmission. • Disassembly Fixtures • During disassembly, the transmission is placed on the bench and torn down. • It is usually placed upside down and rolled over as needed.

12. FIGURE 16-6 A transmission-holding fixture (arrows) has been mounted onto this transmission. It will allow the transmission to be rotated to the best working position. The round stem at the left will be slid into a bench fixture. TRANSMISSION DISASSEMBLY

13. FIGURE 16-7 This simple, shop-made stool (a) has a hole for the transmission output shaft (b). The output shaft of this transmission being repaired has been placed through the rear opening of an empty case (c). Caution should be exercised if using either support method. Because of the narrow bases, they can tip over. TECH TIP • Some shops use a simple fixture that resembles a threelegged stool; other shops simply use an old transmission case in a rear-side-up position.

14. PRELIMINARY DISASSEMBLY • The first teardown step is to remove the oil pan, filter, and valve body. • Many technicians use the oil pan to store the retaining rings, screws, bolts, and other small parts removed during disassembly. • The procedure is to remove the pan, inspect the debris (if it has not been done already), wash the pan in solvent, and air dry it Next, the filter and gasket are removed and set aside for comparison with the new filter. • The valve body is then removed and set aside for cleaning and inspection

15. FIGURE 16-8 The valve body can be removed after the pan. Some valve bodies have a throttle cable or fluid tubes that need to be disconnected. PRELIMINARY DISASSEMBLY

16. FIGURE 16-9 Oil tubs/pipes are removed by gently prying upward. Note the block of wood to protect the case. (Courtesy of Toyota Motor Sales USA, Inc.) PRELIMINARY DISASSEMBLY • Some transmissions use steel tubes to transfer a fluid passage from one location to another. • These tubes normally use an O-ring to seal each end and are held in place by a retaining bracket.

17. FIGURE 16-10 This transmission has four accumulators under the valve body (a). Note the differences in the springs and pistons and remove them. Compressed air can be used to lift the piston out of its bore (b). PRELIMINARY DISASSEMBLY

18. FIGURE 16-11 This accumulator cover retaining ring is being removed using a pair of snap ring pliers. Some can be pried out of the groove and bore using a small screwdriver or seal pick. (Courtesy of Chrysler Corporation) FIGURE 16-12 The punch is passing through a hole in the case to push the retaining ring out of the groove. This allows a seal pick or small screwdriver to pry the retaining ring out. PRELIMINARY DISASSEMBLY

19. FIGURE 16-13 This accumulator plate/cover is retained by a retaining ring, and the accumulator spring is pushing upward on the cover (a). With the cover removed, the piston and spring can be removed (b). (Courtesy of Chrysler Corporation) PRELIMINARY DISASSEMBLY

20. FIGURE 16-14 The most common styles of retaining rings are external, pin type (a), internal pin type (b), plain external (c), plain internal (d), and E-clip (e). SPECIAL NOTES ON RETAINING RINGS • A retaining ring is commonly used to hold a part in place. • It can hold a gear in position on a shaft or a servo cover in a bore.

21. FIGURE 16-15 Snap ring pliers for external pin type (a), internal pin type (b), and three different styles for plain external snap rings (c–e). The bottom pliers have jaws that open in a parallel action. (Courtesy of Snap-On Tools) SPECIAL NOTES ON RETAINING RINGS

22. FIGURE 16-16 Input shaft end play is an important check for internal wear in a transmission. Note that a more accurate check is made if the input shaft is vertical. (Courtesy of Chrysler Corporation) PRELIMINARY DISASSEMBLY • End-Play Check • It is standard practice to measure the input shaft end play before removing the pump. • End play is the in-and-out movement of the shaft. • To measure input shaft end play, you should do the following:

23. FIGURE 16-17 The dial indicator can be attached to the transmission case or pump (left) or to the input shaft (right). Moving the input shaft will show the end play on the indicator dial. PRELIMINARY DISASSEMBLY

24. FIGURE 16-18 This special tool is used to pull the pump. It can also be attached to the input shaft to allow the shaft to be lifted so end play can be measured. PRELIMINARY DISASSEMBLY

25. FIGURE 16-19 A dial indicator should be set up with the indicator stem parallel to the input shaft and the stem is loaded about one revolution of the indicator dial (1). Next, move the input shaft completely into the transmission (2),and rotate the dial to zero the needle (3).When the input shaft is lifted, the amount of end play can be read on the indicator dial. TECH TIP • The measuring stylus must be parallel to the input shaft. • The indicator body should be adjusted to load the stylus about one full needle rotation

26. FIGURE 16-20 These special tools allow measuring gear train end play so that it can be properly adjusted. (Courtesy of Chrysler Corporation) PRELIMINARY DISASSEMBLY

27. FIGURE 16-21 This transmission uses 12 different selective thrust plates for the No. 4 position. The proper thrust plate is selected to adjust the input shaft end play. (Courtesy of Chrysler Corporation) PRELIMINARY DISASSEMBLY

28. FIGURE 16-22 This special tool is used to measure the servo piston rod stroke as the servo is applied. A different piston rod can be installed if needed. (Courtesy of Toyota Motor Sales USA, Inc.) PRELIMINARY DISASSEMBLY • Other Predisassembly Checks

29. PUMP REMOVAL • The pump assembly is the front cover that holds the gear train inside the case on RWD transmissions. • Its removal allows the disassembly of the rest of the internal parts. • The pump is held in place by a set of bolts. • The close fit between the outer pump diameter and the case plus a rubber sealing ring and/or gasket makes pump removal a little difficult. • Several methods can be used to remove the pump. • These include slide hammers, special screw-type pullers, and prying on the gear train.

30. PUMP REMOVAL • To pull a pump using slide hammers, you should do the following: • To pull a pump using a screw-type puller, you should do the following: • To pull a pump by prying, you should:

31. FIGURE 16-23 This section of a front pump shows a hole that has internal threads to accept a slide hammer. PUMP REMOVAL

32. FIGURE 16-24 A pair of slide hammers has been threaded into the pump assembly (a). After the pump has pulled free, the tools are used to lift the pump out of the transmission (b). (Courtesy of Chrysler Corporation) PUMP REMOVAL

33. FIGURE 16-25 This special service tool is attached to the front pump. Turning the center bolt will push against the input shaft to lift the pump from the transmission. PUMP REMOVAL

34. FIGURE 16-26 Tool J24773-A is connected to the front pump, turning the center bolt will lift the pump (a). A similar tool is attached to this pump (b). An aftermarket tool will serve the same purpose on a variety of pumps; note the valve protector (arrow) to prevent damage to the check valve at the end of some input shafts. PUMP REMOVAL

35. FIGURE 16-27 Removal of the upper pan/chain cover (361), valve body and pump (419 and 320), and the channel plate (280) allows access to the sprockets (575 and 602) and drive chain (82) along with the other parts of the gear train. (Courtesy of Slauson Transmission Parts,www.slauson.com) PUMP REMOVAL • Transaxles Using Input Chain Drive • Some transaxles use a chain and sprockets for gear train input. • The main gear train is behind the valve body; case cover, channel plate, or chain cover; and drive chain and sprockets.

36. FIGURE 16-28 Drive chain and sprocket wear is normally checked by moving the chain inward and outward. Excess movement indicates excessive wear. (Courtesy of BergWarner,Morse TEC) PUMP REMOVAL

37. FIGURE 16-29 The drive chain and the sprockets can be lifted off the case. Note the position of the master link, where the thrust washers are, and how they fit onto the sprockets as you remove them. They must be replaced correctly in this same position. (Reprinted with permission of General Motors) PUMP REMOVAL

38. MAJOR DISASSEMBLY • A service manual should be followed for the disassembly procedure. • Some transmissions almost fall apart after the pump is removed; others come apart one piece at a time. • To complete transmission disassembly, you should:

39. FIGURE 16-31 This input shaft and clutch hub with planetary gears is lifted out of the case. (Courtesy of Toyota Motor Sales USA, Inc.) FIGURE 16-30 Removal of the band strut frees this band so it can slide out of the case. (Courtesy of Chrysler Corporation) MAJOR DISASSEMBLY

40. FIGURE 16-33 This governor assembly is being removed from the transfer shaft of this transaxle. (Courtesy of Chrysler Corporation) FIGURE 16-32 Removal of the retaining bolts allows the extension housing and overdrive unit to be removed from this 42RH transmission. (Courtesy of Chrysler Corporation) MAJOR DISASSEMBLY

41. FIGURE 16-34 The entire gear train of some transmissions is removed as an assembly (a). The gear train of other transmissions is removed one section at a time (b). MAJOR DISASSEMBLY

42. FIGURE 16-34 (CONTINUED) The entire gear train of some transmissions is removed as an assembly (a). The gear train of other transmissions is removed one section at a time (b). MAJOR DISASSEMBLY

43. FIGURE 16-35 Parts 7376, 2341, 9891, and 250 are thrust washers that keep parts properly separated. Parts 9861,7645,3956,7831,8643,and 3485 are retaining rings that hold components in the proper position. (Courtesy of Slauson Transmission Parts,www.slauson.com) MAJOR DISASSEMBLY

44. FIGURE 16-36 It is a good practice to place index marks on the driving lugs (arrows) so the direct clutch shell and the low/intermediate ring gear can be assembled in the original position. TECH TIP • During disassembly, it is a good practice to place index marks on both parts.

45. FIGURE 16-37 Like a center support, this clutch pack is retained by a large retaining ring (a). A large screwdriver can be modified to hook the retaining ring for quick and easy removal (b). The special tool is being used to lift the overdrive support assembly (c). (a is courtesy of Chrysler Corporation) MAJOR DISASSEMBLY

46. FIGURE 16-38 The low/reverse support/anticlunk spring (680) is removed with the low/reverse support. (Reprinted with permission of General Motors) MAJOR DISASSEMBLY

47. FIGURE 16-39 The retaining ring (a) locates the clutch pack in the rear of this case (b). MAJOR DISASSEMBLY

48. FIGURE 16-40 The special tool is used to compress the clutch piston return springs (a) so the retaining ring can be removed (b). MAJOR DISASSEMBLY

49. FIGURE 16-41 With the retaining ring removed, slowly release the spring compressor; make sure that the spring retainer does not catch on the snap ring groove. SAFETY TIP • When using a spring compressor, compress the springs just enough to allow the snap ring to be removed.

50. FIGURE 16-42 Removal of the bracket allows the park rod to be removed (a). Then the park/lock pawl and shaft can be removed (b). MAJOR DISASSEMBLY