1988 Jeep Cherokee


Chrysler Corp., GM Corp., Jeep - New Process 207 & 231

Dodge; B1500 & Dakota

GMC/Chevrolet; "T" Series (Blazer & Jimmy)

Jeep; Cherokee, Comanche, Grand Cherokee, Wagoneer, Wrangler


Transfer case can be identified by an I.D. tag, located on rear case. I.D. tag provides model number, serial number and low range ratio. Date of manufacture is the serial number (I.D. number). This information is necessary when ordering parts.


Model 231 transfer case is a part time, chain-driven, 4-position unit with 2-piece aluminum case. Torque input in 4WD high and low range is undifferentiated. 2WD operation is achieved by a vacuum shift motor. Shift motor disconnects right front axle when 2WD is selected. Vacuum shift motor is controlled by a vacuum switch located on front of transfer case and actuated by shift sector.



Chrysler Corp.

Shift transfer case to 2H position. Raise and support vehicle. Loosen lock bolt at trunnion. Ensure linkage rod slides freely in trunnion. Verify transfer case range lever is fully engaged in 2H position. Tighten lock bolt at trunnion. Lower vehicle. Check shift linkage operation. Ensure transfer case shifts into and operates properly in all gear ranges.

General Motors

Remove shift lever knob retainer. Remove shift lever knob. Remove floor console. Place shift lever in Neutral. Pry control cable end from shift lever. Loosen control cable lock nut. Check transfer case to ensure it is in Neutral. Ensure shift lever is in Neutral. Turn shift lever end of cable in or out as needed until it is aligned with shift lever. Install control cable on shift lever. Tighten control cable lock nut.


Shift transfer case to 4L position. Raise and support vehicle. Loosen lock bolt at trunnion. Ensure linkage rod slides freely in trunnion. Verify transfer case range lever is fully engaged in 4L position. Tighten lock bolt at trunnion. Lower vehicle. Check shift linkage operation. Ensure transfer case shifts into and operates properly in all gear ranges.



Shift to 2WD position. Locate vacuum switch on front of

transfer case. Apply 15 in. Hg vacuum to "L". See Fig. 1. Vacuum should be present at "M". Connect a vacuum gauge to "N". Shift to 4WD position. Apply vacuum to "L". Vacuum should be present at "N". If switch fails any test, replace switch.


Fig. 1: Testing Vacuum Switch Courtesy of Chrysler Corp.



Will Not Shift Or Difficult To Shift Into Gear Vehicle speed too high; slow vehicle to 2-3 MPH to shift. Vehicle operated too long on dry paved surface; stop vehicle and place in Reverse or Neutral to relieve driveline torque. Ensure transfer case external linkage is not binding. Ensure correct fluid is used. Internal parts may be worn or damaged.

Noisy In All Gears

Check fluid level. Ensure correct fluid is used. If fluid is okay, locate possible internal mechanical problem.

Jumps Out Of Gear Or Noisy In 4WD

Transfer case not completely in gear; check shift linkage. Range fork damaged. Shift fork pads are worn or shift fork binding. Low range gear worn.

Fluid Leaking From Vent Or Seals

Transfer case overfilled. Vent plugged. Output shaft seals are damaged or not installed properly.



Removal & Installation

1) Mark front drive shaft and flange for installation

alignment reference. Remove front drive shaft. Remove flange. Discard washer and nut. Using a screwdriver, carefully remove oil seal. Ensure seal contact surface is clean.

2) Apply ATF to seal lip and flange seal surface. Install NEW
oil seal. Install flange and NEW washer and nut. Tighten nut to
specifications. See TORQUE SPECIFICATIONS. Install front drive shaft
using alignment marks. Check transfer case fluid.


Removal & Installation

1) Mark rear drive shaft and flange for installation

alignment reference. Remove rear drive shaft. Tap extension housing in a clockwise direction and remove extension housing. DO NOT pry on extension housing. Using a screwdriver, remove oil seal from extension housing.

2) Using bushing driver, replace bushing in extension
housing. Install NEW extension housing oil seal. Apply silicone
sealant to extension housing mating surface. Install extension
housing. To complete installation, reverse removal procedure.




  1. Shift transfer case into 4H and disconnect battery
    negative cable. Raise vehicle, remove skid plate and drain fluid.

  2. Mark front and rear output shaft yokes to drive shafts for
    reassembly reference. Support transfer case and remove rear
    crossmember. Remove drive shafts.

  3. Disconnect vehicle speed sensor electrical connector and
    vacuum (hoses) harness at transfer case. Remove shift lever or linkage
    rod from case. Remove transfer case attaching bolts. Remove transfer
    case from vehicle.


  1. Clean all old gasket material from transmission and
    transfer case mating surfaces. Position NEW gasket on transfer case
    with orientation tab at upper left bolt hole.

  2. Install transfer case, aligning splines of input shaft
    with transmission. Slide transfer case forward until seated against
    transmission. Install transfer case attaching bolts and tighten to
    specification. See TORQUE SPECIFICATIONS. Install rear crossmember.

  3. Attach shift lever and connect speed sensor electrical
    connector and vacuum harness at transfer case. Using reference marks
    made during removal, reinstall front and rear drive shafts. Refill
    transfer case. Install skid plate and lower vehicle. Connect negative
    battery cable. Road test vehicle.


  1. Remove front companion yoke. See Fig. 2 or 3. Discard
    washer and nut. Shift transfer case to 4L and remove extension
    housing. Remove rear bearing snap ring. Using
    2 screwdrivers under
    each tab, remove retainer housing. Remove rear case and oil pump as an

  2. Remove oil pump pick-up screen and tube from rear case.
    Remove oil pump. Remove "O" ring from oil pump and discard. DO NOT
    separate oil pump halves. Pump must be replaced as an assembly if

  3. Remove mode spring. Using a soft hammer, tap front output
    shaft upward and remove with drive chain as an assembly. Remove
    mainshaft, mode fork and shift rail as an assembly. Remove mode fork
    and shift rail from synchronizer sleeve.

  4. Mark synchronizer sleeve position for reassembly
    reference. Remove synchronizer sleeve from mainshaft. Remove
    synchronizer hub snap ring. Remove synchronizer hub, stop ring and
    drive sprocket. Slide range fork pin out of sector.

  5. Remove range fork and shift hub as an assembly. Remove
    range lever from sector shaft. Remove shift sector, bushing and
    ring. Remove shift detent pin, spring and plug. Remove front bearing
    retainer. Remove input gear snap ring.

  6. Press input and low range gear assembly from input gear
    bearing. Remove low range gear snap ring. Remove input gear retainer,
    thrust washers and input gear from low range gear.

  7. Remove all oil seals. Remove magnet from front case.
    Remove front bearing snap ring. Using a plastic hammer, remove front
    bearing. Press input gear bearing from front case.

  8. Using slide hammer and internal puller, remove input gear
    pilot bearing. Press bearings from drive sprocket. Using internal
    puller and slide hammer, remove output shaft rear bearing.

  9. 24 25 26

    1. Front Companion Flange Nut

    2. Front Companion Flange Seat

    3. Front Companion Flange

    4. Front Output Shaft Seal

    5. Snap Ring

    6. Front Output Shaft Bearing

    7. Case Plug

    8. Vacuum Switch

    9. Gasket

    1. Front Case

    2. Low Range Lock Plate

    3. Input Gear Seal

    4. Input Gear Front Bearing

    5. Input Gear Rear Bearing

    6. Thrust Bearing Washer

    7. Input Gear Thrust Bearing

    8. Input Gear

    9. Input Gear Cup Plug

    10. Mainshaft Pilot Bearing

    11. Planetary Thrust Washer

    12. Annulus Gear

    13. Front Thrust Ring

    14. Planetary Gear

    15. Rear Thrust Ring

    16. Planetary Retaining Ring

    1. Snap Ring

    2. Synchronizer Front Spring

    3. Synchronizer Struts

    4. Synchronizer Hub

    5. Synchronizer Rear Spring

    6. Synchronizer Sleeve

    7. Synchronizer Stop Ring

    8. Mainshaft

    9. Thrust Washer

    10. Drive Sprocket Rear Bearing

    11. Drive Sprocket Front Bearing

    12. Drive Chain

    13. Drive Sprocket

    14. Front Output Shaft Bearing

    15. Front Output Shaft

    16. Range Fork Pads

    17. Range Fork Front Bushing

    18. Range Fork

    19. Range Fork Rear Bushing

    20. Shift Rail

    21. Shift Rai! Bracket

    22. Mode Fork Pads

    23. Mode Fork Front Bushing

    Fig. 2: Exploded View Of Transfer Case (Model 207) Courtesy of Chrysler Corp.

    Mode Fork

  10. Mode Fork Cup

  11. Mode Fork Spring

  12. Mode Fork Rear Bushing

  13. Rear Case

  14. Oil Pump

  15. Speedometer Drive Gear

  16. Pump Housing Seal

  17. Oil Pump Housing

  18. Mainshaft Rear Bearing

  19. Rear Bearing Snap Ring

  20. Rear Retainer

  21. Vent Assembly

  22. Extension Housing

  23. Extension Housing Seal

  24. Fill Plug

  25. Drain Plug

  26. Magnet

  27. Shift Sector

  28. Spacer

  29. Sector Detent Spring

  30. Detent Spring Bolt

  31. Range Lever Nut

  32. Range Lever

  33. "O" Ring Retainer

  34. "O" Ring


  1. Front Companion Yoke,
    Nut, Washer
    & Seal

  2. Detent Plug, Spring & Pin

  3. Front Retainer & Seal

  4. Front Case

  5. Vacuum Switch & Seal

  6. Vent Assembly

  7. Input Gear Bearing & Snap Ring

  8. Low Range Gear Snap Ring

  9. Input Gear Retainer

  1. Low Range Gear Thrust Washers

  2. Input Gear

  3. Input Gear Pilot Bearing

  4. Low Range Gear

  5. Range Fork Shift Hub

  6. Synchronizer Hub Snap Ring

  7. Synchronizer Hub Springs

  8. Synchronizer Hub & Inserts

  9. Synchronizer Sleeve

  10. Synchronizer Stop Ring

  11. Snap Ring

  12. Output Shaft Front Bearing

  13. Front Output Shaft

  1. Drive Sprocket

  2. Drive Chain

  3. Drive Sprocket Bearings

  4. Output Shaft Rear Bearing

  5. Mainshaft

  6. Oil Seal

  7. Oil Pump Assembly

  8. Rear Bearing

  9. Snap Ring

  10. Rear Case

  11. Fill Plug

  12. Drain Plug

  13. Rear Retainer

  1. Extension Housing

  2. Bushing

  3. Oil Seal

  4. Oil Pick-Up Screen

  5. Tube Connector

  6. Oil Pick-Up Tube

  7. "O" Ring

  8. Magnet

  9. Range Lever Nut & Washei

  10. Range Lever

  11. "O" Ring & Seal

  12. Sector

  13. Mode Spring

  14. Mode Fork

  15. Mode Fork Pads

  16. Range Fork Pads

  17. Range Fork Bushings

  18. Range Fork

92 H13083

Fig. 3: Exploded View Of Transfer Case (Model 231) Courtesy of Chrysler Corp.


Clean all parts with solvent. Dry with compressed air. Replace all oil seals, "O" rings and snap rings. Check all parts for wear or damage. Replace all worn or damaged parts. If low range annulus gear inside front case is damaged or worn, front case and gear must be replaced as an assembly. Replace oil pump as an assembly if any part is damaged or worn.


NOTE: When installing bearings, ensure bearing bores are aligned with oil feed holes.

1) Lubricate all parts with Dexron III before installing.

Install output shaft front bearing with NEW snap ring. Install output shaft oil seal in front case. Install snap ring on NEW input gear bearing. See Fig. 2 or 3.

  1. Press input gear bearing so snap ring is seated against
    case. Using press, install NEW input gear pilot bearing. Assemble low
    range gear, input gear, thrust washers and retainer.

  2. Install snap ring. Ensure snap ring is seated in low range
    gear groove. Start input gear shaft into bearing in front case. Press
    input shaft gear into bearing.

CAUTION: DO NOT press against end surfaces of gear. Failure to use proper size tool could lead to gear case or thrust washer damage.

  1. Install input gear snap ring. Install oil seal in front
    bearing retainer. Apply a
    1/8" bead of silicone sealant to retainer
    mating surface. Align oil channel in retainer with oil feed hole in
    case. Install retainer on case. Tighten bolts to specification.

  2. Install sector shaft "O" ring and bushing. Install range
    sector in case. Install range lever and nut. Install detent, detent
    spring and plug. Tighten to specification. See TORQUE SPECIFICATIONS.
    Install NEW pads and fork rail bushings on range fork. Install range
    fork and shift hub.

  3. Ensure range fork pin is engaged with range sector slot.
    Press front bearing in drive sprocket until bearing is flush with bore
    edge. Install rear bearing until bearing is
    3/16" below bore edge. See
    Fig. 4.

  4. Install inserts and spring in synchronizer hub. Install
    sprocket on mainshaft
    . Install synchronizer stop ring on mainshaft.
    Ensure stop ring is seated. Install synchronizer hub on mainshaft.
    Align and seat hub inserts on stop ring lugs. Install synchronizer hub
    snap ring.

  5. Install synchronizer sleeve on hub. Ensure sleeve is
    positioned so beveled spline ends are facing stop ring. Ensure sleeve
    tooth is aligned (centered) over each synchronizer strut. Gear clash
    will occur if strut and sleeve teeth are misaligned. Install NEW pads
    on mode fork. Engage mode fork in synchronizer sleeve. Install
    mainshaft and fork assembly in case. Ensure mode fork shift rail is
    seated in both range fork bushings.

  6. Install output shaft and drive chain assembly. Install
    mode spring on shift rail. Using bearing driver, install output shaft
    rear bearing. Lubricate bearing after installation. Install seal in
    oil pump feed housing. Install oil pump in housing. Tighten to

  1. Install oil pick-up tube "O" ring in oil pump. Prime oil
    pump by pouring ATF into pump through pick-up tube opening. Install
    oil pump and pick-up tube in case. Ensure oil screen is properly
    positioned. See Fig. 5. Install magnet in front case. Apply 1/8" bead
    of silicone sealer to front case. Install rear case. Tighten to
    specification. See TORQUE SPECIFICATIONS. Ensure mainshaft splines are
    engaged with oil pump inner gear and a washer is used on bolts at
    dowel locations.

  2. Install rear bearings in retainer. Apply 1/8" bead of
    silicone sealer and install retainer to case. Install rear retainer
    snap ring. Install extension housing. Install front companion yoke.
    Install NEW gasket on vacuum switch. Install vacuum switch in case.
    Fill transfer case with Dexron III.


Fig. 4: Installing Drive Sprocket Bearings Courtesy of Chrysler Corp.

Fig. 5: Identifying Oil Pump Screen Position Courtesy of Chrysler Corp.



Application Ft. Lbs. (N.m)

Companion Flange Nut

Chrysler Corp 130-200 (176-271)

General Motors 80 (108)

Jeep 110 (149)

Detent Plug

General Motors 11 (15)

Chrysler Corp. & Jeep 15 (20)

Drain & Fill Plug 30-40 (41-54)

Extension Housing Bolt 20-25 (27-34)

Front Bearing Retainer Bolt

Chrysler Corp. & Jeep 16 (22)

General Motors 14 (19)

Front Case-to-Rear Case Bolt Chrysler Corp.

Flange Head Bolt 35-45 (47-61)

All Other Bolts 20-25 (27-34)

General Motors 23 (31)

Jeep 20-25 (27-34)

Range Lever Nut 15-20 (20-27)

Rear Bearing Retainer Bolt 20-25 (27-34)

Rear Crossmember 30 (41)

Shift Lever Lock Bolt 10 (14)

Speed Sensor Bolt 23 (31)

Transfer Case-to-Transmission Nut 26 (35)

Vacuum Switch

Chrysler Corp 15-25 (20-34)

General Motors 17 (23)

Jeep 20-25 (27-34)

Control Cable Lock Nut 18 (2)


For vacuum diagrams, refer to appropriate VACUUM DIAGRAMS article in the ENGINE PERFORMANCE section.