Dismantling, Overhaul and Reassembly

Borg Warner Transfer Gearbox

Dismantling, Overhaul And Reassembly

Service Tools. See Service tools, Adapter Plate Transfer Box
18G1422 - Oil seal replacer
18G1205 - Adjustable flange holding wrench 18G134 - Bearing and oil seal replacer LST550 - 6 - Input shaft oil seal replacer

NOTE: Before commencing the overhaul procedure thoroughly clean the exterior of the transfer gearbox. If the gearbox oil has not previously been drained, drain the oil into a suitable container.

Dismantling

NOTE: Before commencing the dismantling procedure remove the brake drum assembly.

Rear output housing
1. Remove the six bolts and withdraw the rear output housing complete with output shaft.







Front output housing

NOTE: Invert the gearbox. Level up the assembly by placing wooden blocks under the transfer gearbox to main gearbox joint face.

2. Remove the eight bolts and withdraw the front output housing complete with viscous unit.







Front cover - main casing
3. Remove the eleven bolts securing the front and rear cover (main case) together.







4. Clean any previous sealant from the threads of the bolts.
5. Using two levers between the cast lugs on the outer edges of the casing, to assist in separating the gearbox, carefully prise the front cover from the rear cover.

CAUTION: Do not lever between the mating faces.







Transfer sprocket, centre differential, assembly and chain

NOTE: Before dismantling, mark one chain link and corresponding tooth on the transfer sprocket with an identification line. This is to ensure that the balance of the unit is maintained when reassembled with original components and that the chain is fitted the correct way up.

6. Remove the circlip retaining the transfer sprocket to the transfer shaft.
7. Place two thin pieces of wood on the joint face to prevent damage and using two levers behind the differential assembly carefully lever the differential bearing from its bore while simultaneously easing the transfer sprocket off the transfer shaft to maintain alignment during removal.
8. Remove the transfer sprocket from the chain.
9. Remove the differential assembly from the chain.







Bearing carrier and transfer shaft
10. Insert a screw driver between the anti - rotation dowel and snap ring gently prise the snap ring out of the groove.
11. Withdraw the carrier complete with transfer shaft.
12. Withdraw the anti - rotation dowel.







Selector fork assembly
13. Using Torx bit 25 remove the screw securing the selector arm to the selector lever shaft.
14. Remove the retaining clip securing the selector fork arm to the selector lever shaft.
15. Using Torx bit 25 remove the screw retaining the selector lever.
16. Remove the selector lever shaft from the case and fork assembly.
17. Withdraw the selector fork assembly and selector sleeve.







18. Retrieve the selector plunger and spring from the rear cover.

Planetary set (Epicyclic unit)
19. Turn the case over and prise the end cap off the planetary set housing.
20. Remove the circlip retaining the sun gear shaft.







21. Turn the casing over and remove the large snap ring retaining the planetary set.
22. Withdraw the annulus and planetary assembly from the planetary set housing, complete with oil pump, feed pipe and filter.