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21 - 130
TRANSFER CASE
•
NP205 T R A N S F E R C A S E
INDEX
Page
General Information
130
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . .
130
Shift Linkage Adjustment
132
Speedometer Service .
132
Transfer Case Assembly .
136
Page
Transfer Case Disassembly
135
Transfer Case Identification
130
Transfer Case Lubricants
130
Transfer Case Removal
132
GENERAL INFORMATION
The NP205 transfer case is a gear drive u n i t w i t h
a one-piece, cast i r o n gear case. The N P 205 provides
four operating ranges w h i c h are: four-wheel drive
h i g h , n e u t r a l , two-wheel drive h i g h and four-wheel
drive l o w (Fig. 1). T h e NP205 i s used i n W-250/350
models.
The transfer case g e a r t r a i n consists o f constant
mesh, helical gears. T h e gears rotate on shafts sup-
ported b y b a l l a n d r o l l e r bearings. S l i d i n g clutch
sleeves and shift forks are used to engage or disen-
gage the transfer case drive gears.
The NP205 g e a r t r a i n provides h i g h and low ranges
i n four-wheel mode. T h e h i g h range has a 1:1 r a t i o
for n o r m a l operation and a l o w range w i t h a reduc-
t i o n r a t i o o f 1.96:1 for off road or heavy operation. I n
two-wheel drive range, the transfer case front o u t p u t
shaft drive gear is disengaged. Torque is not t r a n s -
m i t t e d t o the front propeller shaft.
Fig. 1 NP205 Transfer case
TRANSFER CASE LUBRICANTS
Recommended
lubricants for t h e NP205 transfer
case include m u l t i
purpose gear oils a n d single
weight engine oils.
Engine o i l should be A P I classification SF/CC or
SF/CD. Use S A E 30 a t a m b i e n t temperatures below
0° C ( + 32° F) a n d S A E 50 a t temperatures above
t h i s point.
SAE multipurpose gear oils o f A P I , G L 5 q u a l i t y
can be used w h e n heavy d u t y operation i s a n t i c i -
pated. S A E 80, 90 and 140 are a l l acceptable. Use
SAE 80 w h e n ambient temperatures are below -23° C
(-10° F) or S A E 90 w h e n temperature is above t h e
stated range. S A E 140 can be used w h e n severe ser-
vice is anticipated, or w h e n a m b i e n t temperatures
are expected t o exceed +32° C (90° F)
The transfer case shift l i n k a g e pivot and contact
surfaces should be l u b r i c a t e d w i t h engine o i l a t rec-
ommended intervals. L u b r i c a t i o n frequency for t h e
linkage is described i n Group O, L u b r i c a t i o n A n d
Maintenance.
TRANSFER CASE IDENTIFICATION
The NP205 i d e n t i f i c a t i o n t a g is attached t o t h e
PTO cover on t h e d r i v e r side o f the transfer case.
The tag contains transfer case m a n u f a c t u r i n g and as-
sembly p a r t numbers. Refer to t h i s i n f o r m a t i o n w h e n
ordering service replacement parts.
SERVICE DIAGNOSIS
The most frequent causes of transfer case malfunc-
tions are improper operation, insufficient l u b r i c a n t ,
non-recommended l u b r i c a n t , misadjusted shift l i n k -
age, or improper assembly after repair.
The general problems a n d causes of transfer case
malfunctions are o u t l i n e d below.
LOW LUBRICANT
LEVEL
A low l u b r i c a n t level is u s u a l l y the result of loose
components, leakage, o r improper checking and/or
filling
techniques.
L u b r i c a n t leaks can occur a t the shaft seals, case
vent, or gasket j o i n t s . Most leaks w i l l be evident by
the presence o f l u b r i c a n t around the leakage point.
However, be sure t h e leakage is actually from a
transfer case component. Leakage from other sources
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