LT230Q Transfer Box
TRANSFER BOX
DESCRIPTION AND OPERATION
11
TRANSFER BOX CROSS SECTION
1. Main casing
2. Front output housing
3. Rear output housing
4. Dog clutch
5. Transmission brake
6. Mainshaft input gear
7. Selective shim - input gear bearing pre-load
8. Intermediate gear cluster
9. Intermediate shaft
10. Collapsible spacer
11. Differential assembly
12. Selective shim - differential bearing pre-load
13. Low range gear
14. High/low selector sleeve and hub
15. High range gear and bush
16. Differential rear bearing
17. Front output shaft
18. Differential lock selector shaft
19. Selector fork
20. Rear output shaft
DESCRIPTION
Introduction
The LT230Q transfer box is mounted at the rear of
the main gearbox and transmits drive to the front
and rear axles via the propeller shafts.
The LT230Q, whilst similar to the LT230T differs
mainly in the following areas:
Helix angle of gears increased to 31
°
together with
an increase in the number of gear teeth thus giving
quieter running and an increase in power
transmission efficiency.
Increased length mainshaft input gears together with
increased thickness bearing housing and
repositioned bearing.
Redesigned intermediate gear bearings.
Redesigned high gear bush giving quieter running.
Construction
The transfer box comprises three main assemblies,
the main casing, front output housing and rear
output housing.
The main casing carries the mainshaft input gear,
the intermediate gears and the differential together
with the high/low range gears, selector shaft and
fork.
The front output housing carries the front output
shaft and flange, high/low cross shaft, housing and
selector and the differential lock selector shaft and
fork. A dog clutch on the front output shaft is
operated by the differential lock selector fork to
engage/disengage the differential lock.
The rear output housing carries the output shaft and
flange and the speedometer drive and driven gears.
A mechanically operated transmission brake is
attached to the housing, the brake drum being
attached to the output flange.
All housings and cover plates are sealed to the main
casing by sealant; mud and water ingress being
prevented by mud shields and throwers located at
each end of the output housings and on the output
flanges.
Mainshaft input gear
The gearbox output shaft is splined into the
mainshaft input gear which is supported by taper
roller bearings.
Input gear bearing pre-load is achieved by the use of
a selective shim located in the bearing housing. An
additional power take-off gear is located at the rear
of the input gear for certain applications.