Disassembly

OVERDRIVE UNIT

REMOVAL
1. Shift transmission into PARK.
2. Raise vehicle.
3. Remove transfer case, if equipped.
4. Mark propeller shaft universal joint(s) and axle pinion yoke, or the companion flange and flange yoke, for alignment reference at installation, if necessary.
5. Disconnect and remove the rear propeller shaft, if necessary.
6. Remove transmission oil pan, remove gasket, drain oil and reinstall pan.
7. If overdrive unit had malfunctioned, or if fluid is contaminated, remove entire transmission. If diagnosis indicated overdrive problems only, remove just the overdrive unit.
8. Support transmission with transmission jack.





9. Remove bolts attaching overdrive unit to transmission (Fig. 124).

CAUTION: Support the overdrive unit with a jack before moving it rearward. This is necessary to prevent damaging the intermediate shaft. Do not allow the shaft to support the entire weight of the overdrive unit.

10. Carefully work overdrive unit off intermediate shaft. Do not tilt unit during removal. Keep it as level as possible.
11. If overdrive unit does not require service, immediately insert Alignment Tool 6227-2 in splines of planetary gear and overrunning clutch to prevent splines from rotating out of alignment. If misalignment occurs, overdrive unit will have to be disassembled in order to realign splines.
12. Remove and retain overdrive piston thrust bearing. Bearing may remain on piston or in clutch hub during removal.
13. Position drain pan on workbench.
14. Place overdrive unit over drain pan. Tilt unit to drain residual fluid from case.
15. Examine fluid for clutch material or metal fragments. If fluid contains these items, overhaul will be necessary.
16. If overdrive unit does not require any service, leave alignment tool in position. Tool will prevent accidental misalignment of planetary gear and overrunning clutch splines.

DISASSEMBLY





1. Remove transmission speed sensor and O-ring seal from overdrive case (Fig. 125).





2. Remove overdrive piston thrust bearing (Fig. 126).

OVERDRIVE PISTON





1. Remove overdrive piston thrust plate (Fig. 127). Retain thrust plate. It is a select fit part and may possibly be reused.





2. Remove intermediate shaft spacer (Fig. 128). Retain spacer. It is a select fit part and may possibly be reused.





3. Remove overdrive piston from retainer (Fig. 129).

OVERDRIVE CLUTCH PACK





1. Remove overdrive clutch pack wire retaining ring (Fig. 130).





2. Remove overdrive clutch pack (Fig. 131).





3. Note position of clutch pack components for assembly reference (Fig. 132).

OVERDRIVE GEARTRAIN





1. Remove overdrive clutch wave spring (Fig. 133), 5 disc clutch only.





2. Remove overdrive clutch reaction snap-ring (Fig. 134). Note that snap-ring is located in same groove as wave spring.





3. Remove Torx head screws that attach access cover and gasket to overdrive case (Fig. 135).





4. Remove access cover and gasket (Fig. 136).





5. Expand output shaft bearing snap-ring with expanding-type snap-ring pliers. Then push output shaft forward to release shaft bearing from locating ring (Fig. 137).





6. Lift gear case up and off geartrain assembly (Fig. 138).
7. Remove snap-ring that retains rear bearing on output shaft.





8. Remove rear bearing from output shaft (Fig. 139).

DIRECT CLUTCH, HUB AND SPRING

WARNING: THE NEXT STEP IN DISASSEMBLY INVOLVES COMPRESSING THE DIRECT CLUTCH SPRING. IT IS EXTREMELY IMPORTANT THAT PROPER EQUIPMENT BE USED TO COMPRESS THE SPRING AS SPRING FORCE IS APPROXIMATELY 830 POUNDS. USE SPRING COMPRESSOR TOOL 6227-1 AND A HYDRAULIC SHOP PRESS WITH A MINIMUM RAM TRAVEL OF 5-6 INCHES. THE PRESS MUST ALSO HAVE A BED THAT CAN BE ADJUSTED UP OR DOWN AS REQUIRED. RELEASE CLUTCH SPRING TENSION SLOWLY AND COMPLETELY TO AVOID PERSONAL INJURY.





1. Mount geartrain assembly in shop press (Fig. 140).
2. Position Compressor Tool 6227-1 on clutch hub (Fig. 140). Support output shaft flange with steel press plates as shown and center assembly under press ram.
3. Apply press pressure slowly. Compress hub and spring far enough to expose clutch hub retaining ring and relieve spring pressure on clutch pack snap-ring (Fig. 140).





4. Remove direct clutch pack snap-ring (Fig. 141).





5. Remove direct clutch hub retaining ring (Fig. 142).





6. Release press load slowly and completely (Fig. 143).
7. Remove Special Tool 6227-1. Then remove clutch pack from hub (Fig. 143). Note the orientation of the clutch discs. The clutch pack consists of 23 single-sided discs and they must be installed in the same orientation as they were removed.

GEARTRAIN





1. Remove direct clutch hub and spring (Fig. 144).





2. Remove sun gear and spring plate. Then remove planetary thrust bearing and planetary gear (Fig. 145).





3. Remove overrunning clutch assembly with expanding type snap-ring pliers (Fig. 146). Insert pliers into clutch hub. Expand pliers to grip hub splines and remove clutch with counterclockwise, twisting motion.
4. Remove thrust bearing from overrunning clutch hub.
5. Remove overrunning clutch from hub.





6. Mark position of annulus gear and direct clutch drum for assembly alignment reference (Fig. 147). Use small center punch or scriber to make alignment marks.





7. Remove direct clutch drum rear retaining ring (Fig. 148).





8. Remove direct clutch drum outer retaining ring (Fig. 149).





9. Mark annulus gear and output shaft for assembly alignment reference (Fig. 150). Use punch or scriber to mark gear and shaft.





10. Remove snap-ring that secures annulus gear on output shaft (Fig. 151). Use two screwdrivers to unseat and work snap-ring out of groove as shown.





11. Remove annulus gear from output shaft (Fig. 152). Use rawhide or plastic mallet to tap gear off shaft.

GEAR CASE AND PARK LOCK
1. Remove locating ring from gear case.
2. Remove park pawl shaft retaining bolt and remove shaft, pawl and spring.
3. Remove reaction plug snap-ring and remove reaction plug.
4. Remove output shaft seal.

CLEANING
Clean the geartrain and case components with solvent. Dry all parts except the bearings with compressed air. Allow bearings to air dry.

Do not use shop towels for wiping parts dry unless the towels are made from a lint-free material. A sufficient quantity of lint (from shop towels, cloths, rags, etc.) could plug the transmission filter and fluid passages.

Discard the old case gasket and seals. Do not attempt to salvage these parts. They are not reusable. Replace any of the overdrive unit snap-rings if distorted or damaged.

Minor nicks or scratches on components can be smoothed with crocus cloth. However, do not attempt to reduce severe scoring on any components with abrasive materials. Replace severely scored components; do not try to salvage them.

INSPECTION
Check condition of the park lock components and the overdrive case.

Check the bushings in the overdrive case. Replace the bushings if severely scored or worn. Also replace the case seal if loose, distorted, or damaged.

Examine the overdrive and direct clutch discs and plates. Replace the discs if the facing is worn, severely scored, or burned and flaking off. Replace the clutch plates if worn, heavily scored, or cracked. Check the lugs on the clutch plates for wear. The plates should slide freely in the drum. Replace the plates or drum if binding occurs.

Check condition of the annulus gear, direct clutch hub, clutch drum and clutch spring. Replace the gear, hub and drum if worn or damaged. Replace the spring if collapsed, distorted, or cracked.

Be sure the splines and lugs on the gear, drum and hub are in good condition. The clutch plates and discs should slide freely in these components.

Inspect the thrust bearings and spring plate. Replace the plate if worn or scored. Replace the bearings if rough, noisy, brinnelled, or worn.

Inspect the planetary gear assembly and the sun gear and bushings. If either the sun gear or the bushings are damaged, replace the gear and bushings as an assembly. The gear and bushings are not serviced separately.

The planetary carrier and pinions must be in good condition. Also be sure the pinion pins are secure and in good condition. Replace the carrier if worn or damaged.

Inspect the overrunning clutch and race. The race surface should be smooth and free of scores. Replace the overrunning clutch assembly or the race if either assembly is worn or damaged in any way. Replace the shaft pilot bushing and inner bushing if damaged.

Replace either shaft bearing if rough or noisy. Replace the bearing snap-rings if distorted or cracked.

Check the machined surfaces on the output shaft. These surfaces should clean and smooth. Very minor nicks or scratches can be smoothed with crocus cloth. Replace the shaft if worn, scored or damaged in any way.

Inspect the output shaft bushings. The small bushing is the intermediate shaft pilot bushing. The large bushing is the overrunning clutch hub bushing. Replace either bushing if scored, pitted, cracked, or worn.