Overhaul Dodge Ram I

DESCRIPTION

Two-speed transfer case is mounted on rear of transmission. KM145 is model number for manual transmission/transfer case combination, which uses KM132 5-speed manual transmission. KM146 is model number for automatic transmission/transfer case combination, which uses MA904 3-speed automatic transmission. There are only minor differences between transfer cases and these are due to difference in attachment to manual or automatic transmissions.

Scheme 1

SERVICE INTERVAL

Under normal operating conditions, check oil levels in KM145 models at every 30,000 mile service interval. Change ATF in KM146 models at every 30,000 mile service interval. Under severe usage conditions, change gear oil in KM145 models and, ATF and gear oil in KM146 models at every 30,000 mile interval.

FLUID TYPE

Automatic transmission use ATF. Manual transmission and all transfer cases use hypoid gear oil with API classification of GL-4 and viscosity of SAE 80W or SAE 75W-85W.

CAPACITY

Model KM145 uses 2.3 qts. (2.2L) of gear oil in both transmission and transfer case sections for total of 4.6 qts. (4.4L). Model KM146 uses 7.2 qts. (6.8L) of ATF in transmission section and 2.3 qts. (2.2L) of gear oil in transfer case section.

Removal

1. Remove transfer case skid plate (if equipped). Disconnect both propeller shafts. Drain oil from transfer case. Disconnect wiring harness from back-up light switch and both 4WD switches.
2. Disconnect speedometer cable from drive. Unclip cable from case. Remove back-up light switch and take out steel ball under switch. Remove select plunger bore plug at right side of case. Remove select spring and plunger. Remove 6 bolts holding control lever assembly.
3. Remove control lever assembly and gasket. Remove plugs at top of adapter. Remove detent spring, steel ball, neutral return springs and plungers. Using .22" (5.8 mm) pin punch, drive roll pin out of change shifter. Remove change shifter from control shaft. Remove 4 bolts and 2 nuts holding transfer case to adapter. Remove transfer case from vehicle.

Installation

1. Position transmission Change shifter in "N" position and transfer case lever in "4H" position. Mount neutral return plungers and springs in holes on top of adapter. Tighten plug until it is flush with adapter surface. Cover plug with sealant.
2. Coat inside of change shifter with grease. Mount detent plunger, spring and install plug (if equipped). Install back-up light switch and steel ball. To complete installation, reverse removal procedure. Fill transfer case with oil.

1. Remove transfer case skid plate (if equipped). Disconnect both propeller shafts. Drain oil from transfer case. Disconnect wiring harness from back-up light switch and both 4WD switches. Disconnect speedometer cable from drive and unclip cable from case.
2. Remove bolts holding transfer case and adapter to transmission case. Remove bolts holding transfer case to support bracket. Remove transfer case assembly from transmission. Remove 4 bolts and 2 nuts holding transfer case to adapter. Remove adapter from transfer case.

To install, reverse removal procedure. Fill transfer case with oil.

Scheme 2

Disassembly

1. Remove both 4WD switches and steel balls. Remove speedometer sleeve assembly. Remove cover, gasket, wave spring and spacer. Drive roll pin out of high-low shift fork with 3/16" (4.8 mm) punch.
2. Remove 2 seal plugs. Remove 2 poppet springs and steel balls. Pull high-low shift rail out backward. Remove interlock plunger. Remove snap ring from rear bearing on output shaft. Remove chain cover, oil guide and side cover. Remove countershaft locking plate. Pull countershaft out.
3. Remove countergear, 2 thrust washers, 2 needle bearings and spacer through side cover opening. Remove snap ring, spring retainers and spring from 2WD-4WD shift rail. Remove front output shaft, rear output shaft and chain as assembly.
4. Remove 2WD-4WD shift rail. Remove high-low shift fork and clutch sleeve. Remove needle bearing and snap ring from input gear. Remove input gear assembly. Remove snap ring from front of rear output shaft. Remove high-low clutch hub, low speed gear thrust washer and needle bearing.
5. Remove detent from lock nut of rear output shaft. Remove lock nut. Using bearing puller, remove ball bearing. Remove sprocket spacer and steel balls. Remove drive sprocket, 2 needle bearings, sprocket sleeve and steel ball.
6. Remove 2WD-4WD clutch sleeve, hub and stop plate. Using puller or press, remove ball bearing. Remove snap ring from input gear. Support bearing with press base. Push on front of input gear to remove bearing. Using puller, remove 2 bearings from front output shaft.
7. If either control shaft or input gear oil seals are to be replaced, drive out roll pin from transmission control change shifter. Separate transfer case from adapter.

Scheme 3

Scheme 4

Scheme 5

1. Press control shaft, input gear and front output shaft oil seals into transfer case housing. When fitting seals, press circumference uniformly. Pack grease between lips of installed seals.
2. Join adapter and transfer case with new gasket. Be sure to install change shifter over control shaft before tightening nuts and bolts. Make sure to remove burrs from change shifter. Tighten bolts and nuts.
3. Press bearing into input gear, pushing against inner race. After fitting, make sure that bearing rotates smoothly. Fit selective fit snap ring over front end of input gear. Snap rings are available in 5 thicknesses. Select thickest snap ring that will fit in groove. See «INPUT GEAR BEARING SNAP RING»(/dodge/ram/i-1981-1993/remont/transfer-case/#overhaul) table. INPUT GEAR BEARING SNAP RING Ring Color Thickness In. (mm) None.091 (2.30) Red.093 (2.35) White.094 (2.40) Blue.096 (2.45) Green.098 (2.50)
4. Press 2 ball bearings on front output shaft, pushing against inner race. After fitting, make sure bearings rotate smoothly. Install ball bearing over rear output shaft from rear. Press into place, pushing against inner race. Check for smooth rotation.
5. Install stop plate. Install 2WD-4WD clutch hub and sleeve. Make sure hub and sleeve face correct direction. (Scheme 4) Install steel ball (for sprocket sleeve positioning) on rear output shaft. Install sprocket sleeve.
6. Install 2 needle bearings on outer circumference of sprocket sleeve. Install drive sprocket. Install steel balls and sprocket spacer. Press ball bearing onto inner race. Check for smooth rotation.
7. Tighten mainshaft lock nut. Lock detent with punch. After lock nut is tightened, make sure that drive sprocket rotates smoothly. Install needle bearing, thrust washer and low speed gear on front of rear output shaft.
8. Install needle bearing, thrust washer and low speed gear on front of rear output shaft. Mount high-low clutch hub. Make sure hub faces correct direction. (Scheme 4)
9. Mount high-low clutch hub snap ring on front end of rear output shaft. Selective fit snap rings are available in 5 thicknesses. Use thickest snap ring that will fit in output shaft groove. See the «HIGH-LOW CLUTCH HUB SNAP RING»(/dodge/ram/i-1981-1993/remont/transfer-case/#overhaul) table. HIGH-LOW CLUTCH HUB SNAP RING Ring Color Thickness In. (mm) None.084 (2.14) Yellow.087 (2.21) White.090 (2.28) Blue.093 (2.35) Red.095 (2.42)
10. Install the input gear assembly into the transfer case. Input gear retaining snap rings are available in 5 different thicknesses. Use the thickest snap ring that will fit into the input gear groove. See the «INPUT GEAR RETAINER SNAP RING»(/dodge/ram/i-1981-1993/remont/transfer-case/#overhaul) table. INPUT GEAR RETAINER SNAP RING Ring Color Thickness In. (mm) Purple.106 (2.70) Pink.108 (2.75) Yellow.110 (2.80) White.112 (2.85) Blue.114 (2.90)
11. Insert needle bearing in input gear. Install high-low clutch sleeve and shift fork. Clutch sleeve must face same direction as 2WD-4WD clutch sleeve. Install 2WD-4WD shift rail. (Scheme 4)
12. Engage chain securely on front and rear output shaft sprockets. Assemble 2WD-4WD clutch sleeve with 2WD-4WD shift fork. Install assembly over 2WD-4WD shift rail. Install front and rear output shafts with chain as an assembly.
13. Install 2 spring retainers with spring on 2WD-4WD shift rail. Install snap ring. Insert 2 needle bearings and spacer in countergear. Install assembly in transfer case. Install one thrust washer at each end of countergear.
14. Insert side cover and gasket. Install oil guide. Install chain cover and gasket. Make sure oil guide end fits into chain cover opening. Fit snap ring into groove of rear bearing on rear output shaft. Install interlock plunger.
15. Install high-low shift rail in case and high-low shift fork. High-low shift rail cannot be installed unless 2WD-4WD shift fork is shifted to 4WD side. Install 2 poppet balls and springs. Install seal plug. When installing poppet spring, smaller end must be toward ball.
16. With high-low shift fork and shift rail spring holes aligned, drive in roll pin with punch. Roll pin should be installed with slit on center line of shift rail.
17. Install wave spring on rear of rear output shaft bearing. Install rear cover and gasket. Install wave spring on back of rear bearing on front output shaft. Install cover and gasket.
18. Check clearance between rear end of bearing and cover. (Scheme 5) Clearance should be.079" (2 mm). If clearance is excessive, change spacer to reduce clearance to less than.079" (2 mm). See «OUTPUT SHAFT BEARING CLEARANCE SPACER»(/dodge/ram/i-1981-1993/remont/transfer-case/#overhaul) table. OUTPUT SHAFT BEARING CLEARANCE SPACER Spacer Color Thickness In. (mm) Black.033 (.84) None.037 (.93) Red.040 (1.02) White.044 (1.11) Yellow.047 (1.20) Blue.051 (1.29) Green.054 (1.38)
19. Check output shaft end play. End play should be.00-.04" (0-.1 mm). Install speedometer sleeve assembly in rear cover. Align match mark on speedometer sleeve with mark on case according to number of teeth on speedometer driven gear. Install sleeve clamp and tighten bolt. Install two 4WD light switches with steel balls.

Scheme 6

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• INPUT GEAR BEARING SNAP RING