OBJECTIVES

Automatic Transmissions and Transaxles, Fourth EditionBy Tom Birch and Chuck Rockwood

© 2010 Pearson Higher Education, Inc.Pearson Prentice Hall - Upper Saddle River, NJ 07458

OBJECTIVES

After studying Chapter 11, the reader should be able to:1. Check the fluid level in an automatic transmission.2. Check automatic transmission fluid condition.3. Change the fluid in an automatic transmission.4. Adjust manual shift linkage.5. Adjust throttle linkage.6. Adjust a band in an automatic transmission.7. Complete the SAE tasks related to

transmission/transaxle maintenance and adjustment (see Appendix A).



INTRODUCTION

• Automatic transmissions and transaxles can operate properly for many miles while being totally neglected.

• Some that fail could have had a longer service life if they had been properly maintained.

• Several surveys of transmission shops have produced responses that over 80% of transmission failures were the result of neglecting to change the fluid. Newer transmissions require very little maintenance.



FLUID CHECKS

• The operator of a vehicle should check the fluid level in an automatic transmission periodically.

• A good time is right after every engine oil change. • If the level is low, fluid of the correct type should be

added. • It usually takes one pint (0.5 L) to move the fluid

level from low to the full mark on the dipstick.



FLUID CHECKS

FIGURE 11-1 Most dipsticks have fluid-level markings for various temperatures. The vehicle should not be operated if the level is below the underfill or above the overfill marks.



FLUID CHECKS

• To check transmission fluid, you should:• To check sealed transmission fluid level, you should



FLUID CHECKS

FIGURE 11-2 When checking the fluid level, the engine should be at idle speed, the fluid hot, and the gear selector should be positioned as required by the vehicle manufacturer. Note the fluid level and compare it with dipstick markings. It is also a good practice to note any unusual fluid color or odor.



FLUID CHECKS

FIGURE 11-3 Fluid level on sealed units (without a dipstick) is checked by removing the level plug, which can be mounted in the bottom or side of the pan or in the case.



FLUID CHECKS

• Transaxle Final Drives and Differentials

• Fluid Condition

FIGURE 11-4 Some transaxle differentials have a plug to allow checking of the fluid level in the final drive section. (Courtesy of Chrysler Corporation)



FLUID CHECKS

FIGURE 11-5 A useful chart for checking fluid level and condition. (Reprinted with permission of General Motors)



FLUID CHECKS

FIGURE 11-6 Fluid condition can be checked by placing a sample on clean, white, absorbent paper (a). Clean fluid will spread out and leave only a wet stain (b). Dirty fluid will leave deposits of foreign material.



FLUID CHANGES

• Most manufacturers recommend fluid changes every 100,000 miles (160,000 km) under normal driving conditions.

• Some recommend a fluid change at 50,000 miles (80,000 km).

• Severe driving conditions are described as:– Frequent trailer pulling.– Heavy city traffic, especially in areas where the

temperature exceeds 90°F (32°C).– Very hilly or mountainous conditions.– Commercial use such as taxi or delivery service.– Police or ambulance usage.



FLUID CHANGES

FIGURE 11-7 In many transmissions, the fluid is expected to last 100,000 miles if the fluid temperature can be kept below 175°F (80°C); but the life will be cut in half for every 20°F increase in temperature.



FLUID CHANGES

• Fluid Changing, Dropping the Pan



TECH TIP

FIGURE 11-8 Since most transmissions do not have drain plugs, the fluid must be spilled in a controlled fashion by lowering the pan at an angle. To do this, all but two bolts are removed. As the last two bolts are loosened, the pan will lower and fluid will spill over the edge.



FLUID CHANGES

• To change transmission fluid, you should:

FIGURE 11-9 Fluid is draining from this transmission pan. Note how the pan is hanging from two front bolts.



FLUID CHANGES

FIGURE 11-10 A gasket splitter is used to break the seal between the pan and transmission case. It is tapped in between the pan and case and then tapped sideways, around the pan.



FLUID CHANGES

FIGURE 11-11 The filter is normally located in the oil pan (a); note the magnet inside the pan to trap ferrous metals. The filter is held by three screws (b). (Courtesy of Chrysler Corporation)



FLUID CHANGES

FIGURE 11-12 This pan magnet has a thin coating of very fine iron particles and the pan is fairly clean. This is normal transmission wear.



TECH TIP

• Some technicians will cut the old filter open so they can inspect for foreign particles

FIGURE 11-13 This depth filter has been cut open, and there are only a few small metal particles caught in the fold.



TECH TIP

• Many transmissions are shipped to the vehicle assembly line wet (full of fluid) and a sealing device is used to close the openings for the drive shaft(s) and dipstick tube.

FIGURE 11-14 This “popcycle” was found laying in the transmission pan. It was used to plug the dipstick opening while the transmission was shipped to the vehicle assembly line.



TECH TIP

• If the flange surface is bent or has dimples, it should be flattened using a hammer and block of wood, vise, or anvil.

FIGURE 11-15 The flange area of a pan should be checked for distortion from overtightened bolts. These can be corrected by tapping down the raised areas as

shown.



FLUID CHANGES

FIGURE 11-16 If the transmission fluid and filter are replaced, the proper amount of fluid will overfill the transmission (a). The fill procedure should add fluid to a full level and then start the engine (b). Add additional fluid as needed to bring it to the proper level (c). Checking the engine with the engine off can show an overfill if the converter drains down (d).



FLUID CHANGES

• Fluid Changing, Fluid Evacuator– To change transmission fluid

using an evacuating tool, you should:

• Fluid Exchange and Flush Units– To change fluid using a

transmission fluid exchange unit, you should:

FIGURE 11-17 This fluid evacuation system has a small tube that can be inserted into the transmission dipstick tube. A connection to shop air is used to create a vacuum that sucks the fluid into the container. (Courtesy of ATEC Trans-Tool and Cleaning Systems)



FLUID CHANGES

FIGURE 11-18 This transmission flusher pumps new fluid into the transmission pump intake. It is operated until the old, dirty fluid is forced out. (Courtesy of Goodall Manufacturing)



FLUID CHANGES

FIGURE 11-19 A fluid exchange unit is normally connected to the cooler return line, and it sends new fluid to the transmission to replace the old fluid being captured from the cooler.



MANUAL LINKAGE CHECKS

• The manual linkage is adjustable on most automatic transmissions.

• This ensures the manual valve is positioned correctly relative to the gear selector.

• Linkage position should be checked periodically because a misadjusted linkage can cause the manual valve to leak oil pressure into the wrong passage




FIGURE 11-20 Proper manual linkage ensures that manual valve position (a) matches correctly with the position of the manual shift lever and shift indicator (b). (Courtesy of Chrysler Corporation)




• To check manual linkage adjustment, you should:

FIGURE 11-21 As the shift selector is moved across the quadrant, you should be able to feel the detents inside the transmission. The detent feel should correspond with the gear position. (Reprinted with permission of General Motors)




FIGURE 11-22 This neutral safety switch is mounted in the transmission and operated by the manual lever cam. It always stays in proper adjustment. (Courtesy of Chrysler Corporation)




FIGURE 11-23 This neutral safety switch is mounted to the outside of the transmission case. If the starter operates with the gear selector in a position other than park or neutral, the switch position should be adjusted. (Courtesy of Chrysler Corporation)




• Manual Linkage Adjustment– The manual linkage should be adjusted if the starter

engagements occur in the wrong position or the transmission detents do not align correctly relative to the gear range pointer.

• To adjust manual shift linkage, you should:• Shift Lock Mechanism

– The shift interlock mechanism locks the shifter in park position when the ignition key is removed.




FIGURE 11-24 A floor-mounted shift linkage using a cable (a); a floor-mounted shift linkage using rods (b); and a column-mounted shift linkage using rods (c). Each one has a method of adjusting the length for proper gear positioning (circled). (Courtesy of Chrysler Corporation)




FIGURE 11-24 (CONTINUED) A floor-mounted shift linkage using a cable (a); a floor-mounted shift linkage using rods (b); and a column-mounted shift linkage using rods (c). Each one has a method of adjusting the length for proper gear positioning (circled). (Courtesy of Chrysler Corporation)




FIGURE 11-25 This neutral safety switch is mounted to the outside of the transmission case. If the starter operates with the gear selector in a position other than park or neutral, the switch position should be adjusted. (Courtesy of Chrysler Corporation)




FIGURE 11-26 The manual shift lever is in park. The linkage adjustment is being tightened to lock the adjustment after making sure that the transmission is in park.



THROTTLE LINKAGE CHECKS

• Nonelectronic transmissions may have a throttle rod or cable that connects the engine’s throttle linkage to the transmission’s throttle valve.

• This linkage is commonly called a TV linkage.• The TV linkage controls a valve that produces a rise

in TV or line pressure that is matched to the throttle position.

• To check TV linkage, you should:




FIGURE 11-27 This TV cable connects the throttle body (a) to the transmission (b). The adjustment is at the throttle body cable bracket. (Courtesy of Chrysler Corporation)




• Throttle Linkage Adjustments– Like the manual shift linkage,

TV linkage is adjustable. – Always consult the service

manual for that particular vehicle when making an adjustment.

– To adjust TV linkage, you should:

– Throttle Position Sensor Position Adjustment FIGURE 11-28 This throttle linkage is adjusted by

turning the two adjusting nuts until the cable stopper ring is the correct distance from the housing end.




FIGURE 11-29 This throttle cable uses a “snap lock” adjuster that is adjusted using the procedure shown. (Reprinted with permission of General Motors)




FIGURE 11-30 This “self-adjusting” TV cable is adjusted using the procedure shown. (Reprinted with permission of General Motors)




FIGURE 11-31 This “self-adjusting” TV cable used with some transaxles is adjusted using the procedure shown. (Reprinted with permission of General Motors)




FIGURE 11-32 The throttle position sensor normally has an adjustment so it is positioned correctly on the throttle body. (Courtesy of Chrysler Corporation)



BAND ADJUSTMENTS

• At one time, a common transmission maintenance procedure was to readjust the band clearance.

• Wear of the friction material would increase the clearance to the point where engagement would not be complete and slippage would occur.

• To readjust a band, you should:



BAND ADJUSTMENTS

FIGURE 11-33 When a band is new, the servo piston travels only a short distance to apply it. As the lining wears, servo piston travel increases; if there is too much wear, the band might not tighten completely.



BAND ADJUSTMENTS

FIGURE 11-34 This band is adjusted by holding the adjuster screw while the lock nut is loosened (a). Step 2 turns the adjuster screw inward to 72 in-lbs (8 N-m) of torque. The special adapter is used if there is tight access (b). Step 3 is to back off the adjusting screw the proper number of turns and tighten the lock nut to the correct torque. (Courtesy of Chrysler Corporation)



SUMMARY

1. Automatic transmissions require periodic service and maintenance.

2. Transmission fluid should be regularly checked for correct level and good condition.

3. The transmission fluid should be changed at the required intervals or if the condition indicates the need for a change.

4. The manual shift linkage and the throttle linkage need to be checked and adjusted if necessary.

5. Some transmissions have one or more bands that may need to be adjusted.



REVIEW QUESTIONS

1. Servicing and maintaining an automatic transmission includes:

a. Checking the _________ level.b. Changing the _________.c. Cleaning or replacing the _________.d. Checking and adjusting the _________ and _________ linkages.e. _________ the bands if required.

2. It usually takes _________ _________ to change the fluid level from low to full on the dipstick.

3. Mushy operation, lack of engagement, or slipping can be caused by a transmission that has a fluid level that is too _________.



REVIEW QUESTIONS4. Before checking the fluid level, the vehicle should

a. be on _________ ground.b. be in _________.c. be at normal operating _________.d. have the engine _________.

5. All transaxles share fluid between the differential and the transmission. True or False?

6. When checking the fluid level, the _________ and _________ should also be checked.

7. The normal color of automatic transmission fluid is _________.8. What is indicated by these fluid conditions?

a. Dark brown colorb. Burned odorc. Pink or milky colord. Gold or brown coating on the dipsticke. Metallic appearancef. Foamy



REVIEW QUESTIONS

9. An automatic transmission can be ruined by contaminated _________.10.Severe driving conditions include:

a. Frequent _________ pulling.b. Heavy _________ and _________ traffic.c. _________ weather conditions.d. _________ service.e. _________ or _________ police usage.

11.The major factor that affects transmission fluid life is _________.12.To change fluid in most automatic transmissions, the _________ must

be removed.13.Before installing the clean pan after draining the fluid, check the pan for

_________ and _________ sealing surface.14.The notchy feel and clicking sound when a gear is selected is caused by

the spring-loaded _________.



REVIEW QUESTIONS

15.To properly adjust the manual linkage, always check the manufacturer’s _________ procedures.

16.A sticking, binding, or out-of-adjustment throttle valve cable can cause _________ shifts, _________ shifts, or late, soft, mushy or no downshifts.

17.An exact check for proper throttle valve operation is made using a _________ gauge.

18. It is always necessary to consult a _________ _________ when making a throttle linkage adjustment.

19.Throttle position sensor adjustment will affect _________ operation, vehicle _________, and transmission _________ quality.

20.Many modern automatic transmissions use a band that does not require adjustment because the band is only used for _________ braking and in _________ ranges.



CHAPTER QUIZ

1. Student A says that you should check the transmission fluid level with the engine idling in park. Student B says that if the end of the dipstick is too hot to hold, the fluid can be considered hot. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

1. Student A says that you should check the transmission fluid level with the engine idling in park. Student B says that if the end of the dipstick is too hot to hold, the fluid can be considered hot. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

2. Student A says that on most dipsticks, the distance from the bottom of the cross-hatched area to the top is equal to 1 pint of fluid. Student B says that too much fluid in a transmission can cause poor shifts. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

2. Student A says that on most dipsticks, the distance from the bottom of the cross-hatched area to the top is equal to 1 pint of fluid. Student B says that too much fluid in a transmission can cause poor shifts. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

3. The transmission fluid should be changed if it hasa) black or brown coloration.b) a definite burned smell.c) gone the limit of miles recommended by the

manufacturer.d) Any of these



CHAPTER QUIZ

3. The transmission fluid should be changed if it hasa) black or brown coloration.b) a definite burned smell.c) gone the limit of miles recommended by the

manufacturer.d) Any of these



CHAPTER QUIZ

4. Student A says that too high a fluid level can cause foamy fluid to spill out of the vents or filler pipe. Student B says that too low a fluid level can cause this same problem. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

4. Student A says that too high a fluid level can cause foamy fluid to spill out of the vents or filler pipe. Student B says that too low a fluid level can cause this same problem. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

5. Student A says that all ATF is a bright medium-red color. Student B says that all ATF has the same burnt, oily smell. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

5. Student A says that all ATF is a bright medium-red color. Student B says that all ATF has the same burnt, oily smell. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

6. A pink transmission fluid color indicatesa) normal operation.b) too high a level and air in the fluid.c) water in the fluid.d) None of these



CHAPTER QUIZ

6. A pink transmission fluid color indicatesa) normal operation.b) too high a level and air in the fluid.c) water in the fluid.d) None of these



CHAPTER QUIZ

7. Student A says that transmission fluid life is dependent on the transmission’s operating temperature. Student B says that driving conditions that increase fluid temperature, such as trailer towing or delivery-type operations, shorten fluid life. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

7. Student A says that transmission fluid life is dependent on the transmission’s operating temperature. Student B says that driving conditions that increase fluid temperature, such as trailer towing or delivery-type operations, shorten fluid life. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

8. Student A says that most transmissions can be drained by removing the drain plug. Student B says that you should also change the filter when the fluid is changed. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

8. Student A says that most transmissions can be drained by removing the drain plug. Student B says that you should also change the filter when the fluid is changed. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

9. Student A says that you normally have to start the engine as you refill a transmission with fluid. Student B says that a torque converter can be refilled with the engine off. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

9. Student A says that you normally have to start the engine as you refill a transmission with fluid. Student B says that a torque converter can be refilled with the engine off. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

10.Student A says that if an engine cranks while the gear position indicator is in drive, the manual shift linkage is out of adjustment. Student B says that this problem can be caused by a misadjusted neutral safety switch. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

10.Student A says that if an engine cranks while the gear position indicator is in drive, the manual shift linkage is out of adjustment. Student B says that this problem can be caused by a misadjusted neutral safety switch. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

11.You can quickly check the adjustment of the manual shift linkage bya) trying the operation of the starter in the various gear

positions.b) feeling for the transmission internal detents as you move

the gear selector from park to low.c) feeling for complete engagement of the lever pawl into

the park gate.d) Any of these



CHAPTER QUIZ

11.You can quickly check the adjustment of the manual shift linkage bya) trying the operation of the starter in the various gear

positions.b) feeling for the transmission internal detents as you move

the gear selector from park to low.c) feeling for complete engagement of the lever pawl into

the park gate.d) Any of these



CHAPTER QUIZ

12.Student A says that a misadjusted manual linkage can cause vehicle creep in neutral. Student B says that a gear selector can slip out of park if the linkage is not adjusted correctly. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

12.Student A says that a misadjusted manual linkage can cause vehicle creep in neutral. Student B says that a gear selector can slip out of park if the linkage is not adjusted correctly. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

13.Student A says that most manual linkages can be easily adjusted by repositioning the adjustable end of the rod or cable. Student B says that the selector lever should be positioned in reverse while adjusting the linkage. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

13.Student A says that most manual linkages can be easily adjusted by repositioning the adjustable end of the rod or cable. Student B says that the selector lever should be positioned in reverse while adjusting the linkage. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

14. If the throttle linkage is too short, the transmission will probablya) shift early.b) have very late shifts.c) have soft, mushy shifts.d) Both a and b



CHAPTER QUIZ

14. If the throttle linkage is too short, the transmission will probablya) shift early.b) have very late shifts.c) have soft, mushy shifts.d) Both a and b



CHAPTER QUIZ

15.Student A says that sticky throttle linkage can cause erratic shifts. Student B says that passing gear engagement is affected by the throttle linkage adjustment. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

15.Student A says that sticky throttle linkage can cause erratic shifts. Student B says that passing gear engagement is affected by the throttle linkage adjustment. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

16.Student A says that the bands in modern transmissions can be adjusted using an adjuster screw that extends out at the side of the transmission case. Student B says that if the intermediate band (three-speed transmission) is too tight, there will be a drag in reverse. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

16.Student A says that the bands in modern transmissions can be adjusted using an adjuster screw that extends out at the side of the transmission case. Student B says that if the intermediate band (three-speed transmission) is too tight, there will be a drag in reverse. Who is correct?a) Student Ab) Student Bc) Both A and Bd) Neither A nor B



CHAPTER QUIZ

17.To drain the fluid from the differential of a transaxle,a) remove the transaxle pan.b) drain the differential separately from the transmission.c) check the service manual for the proper procedure.d) There is no need to check the differential fluid.



CHAPTER QUIZ

17.To drain the fluid from the differential of a transaxle,a) remove the transaxle pan.b) drain the differential separately from the transmission.c) check the service manual for the proper procedure.d) There is no need to check the differential fluid.



CHAPTER QUIZ

18.The shift lock mechanism is used to prevent the shifter from being moved out of park unlessa) the brakes are applied and/or the key is in the ignition.b) the doors are closed and the key is in the ignition.c) the seat belts are on and the doors are closed.d) the doors are closed and the brakes are applied.



CHAPTER QUIZ

18.The shift lock mechanism is used to prevent the shifter from being moved out of park unlessa) the brakes are applied and/or the key is in the ignition.b) the doors are closed and the key is in the ignition.c) the seat belts are on and the doors are closed.d) the doors are closed and the brakes are applied.

OBJECTIVES

Documents

pearson higher education

editionby tom birch

chuck rockwood

shouldautomatic transmissions

newer transmissions

fluid checksthe operator

transmission failures

surveys of transmission