New Age PRM 301 Instruction manual

f'""\
PRM 301
BY NEWAGE
WORKSHOP
MANUAL
NEWAGE
NEWAGE TRANSMISSIONS LIMITED
Barlow Road, Coventry, CV2 2LD, Englan'H 1
Telephone: [phone] Telex: 31333
Registered in England, Reg. No. 345283 Registered Office: Barlow Road, Coventry CV2 2LD, England
301 M/85/1

FORWARD
This workshop manual has been prepared to assist the operator or user of
Newage PRM marine gearboxes and also to enable the skilled service engineer to
undertake more detailed maintenance and overhaul.
GENERAL INFORMATION
PRM hydraulic marine gearboxes will give trouble-free service provided they
are correctly installed, aligned and maintained. In the event of failure, the
engine distributor who supplied the gearbox, or the local dealer, should be
informed; where this is not possible, Newage Transmissions Limited, or the
distributor for the area, should be notified. In all communications, verbal
or otherwise, the model and serial number of the gearbox must be quoted in
order to ensure correct identification and supply of parts.
CLAIMS UNDER WARRANTY
Claims for replacement of parts under warranty must always be submitted to the
distributor who supplied the gearbox; if this is not possible, application may
be made to the nearest distributor or dealer, who must, however, be advised of
the supplier's name and address.
SERVICE PARTS
The comprehensive illustrated parts list gives full information and ordering
procedure.
IDENTIFICATION PLATE
Every PRM gearbox is fitted with an identification plate on the top half of
the gearcase before it leaves the factory; an example of such a plate is shown
below.
NEWAGE PRM
123456
3O1VR3
COVENTRY
Al234
USE RECOMMENDED LUBRICANTS ONLY
NEWAGE PRM
COVENTRY
USE RECOMMENDED LUBRICANTS ONLY
Please complete the above box with
serial number and specification of
your own gearbox.
1

It will be noted that there are two lines of numbers.
The top line is the gearbox serial number, and should always be quoted when
ordering spare parts; this enables the factory to trace the history of the
gearbox right back to its date of manufacture and the components and materials
used in its production, thus ensuring that the correct components can be
supplied as spare parts.
The lower line is the gearbox specification; in the example given this
translates as follows:-
First 3 digits - Gearbox model
Fourth digit - Output shaft offset
Fifth digit - Input shaft location
Sixth digit - Ratio
Top Cover
Dipstick
Valve Block
Layshaft
Oil Pump
V
Figure 1. -PRM301 -Cutaway drawing
2
R 3
Taper Bearing
Output Shaft

PRM3O1 SERVICE MANUAL
CONTENTS
1.
2.
3.
4.
5.
6.
7.
GENERAL DATA
1.1 Specifications
1.2 Applications data
1.3 Installation details
INTRODUCTION
CONSTRUCTION
3.1 Gearcase
3.2 Gear train
3.3 Gear train - Angle drive
3.4 Valve block
3.5 Neutral safety start switch
3 .6 Oil pump
OPERATING SYSTEM
4.1 Output rotations
4.2 Hydraulic system
4.3 Lubrication
4.4 Approved oils
INSTALLATION
5.1 General
5.2 Checking the flywheel housing
5.3 Checking the flywheel
5.4 Mounting the gearbox to the engine
5.5 Oil cooler
5.5.1 PRM3O1 standard gearbox
5.5.2 PRM3O1 with power take off
5.5.3 PRM3O1A with angle drive
5.6 Alignment to propeller shaft
5.7 Installation angle
5.8 Twin installations
5.9 Remote control operating unit
OPERATION
6.1 First-time usage
6.2 Drive selection
6.3 Trailing (free-wheeling) the propeller
6.4 Emergency operation
ROUTINE MAINTENANCE
7.1 Initial maintenance (25 hours running)
7.2 Daily checks
7.3 Annual checks
7.4 Winter storage
7.5 Other maintenance operations
3
Page
6
9
9
12
15
21
23

Page
8. FAULT FINDING
23
9.
SERVICING AND REPAIRS
25
9.1 Valve block
9.2 Oil pump
9.3 Removing transmission from boat
9.4 Removing input and layshaft assemblies
9.5 Servicing input and layshaft assembly components
9.5.1 Input shaft oil seal
9.5.2 Drive end bearing
9.5.3 Clutch assembly
9.5.4 Clutch gear
9.5.5 Drive pinion
9.5.6 Non drive end bearing
9.5.7 Piston rings and feeder
9.6
Replacing the input and layshaft
assemblies
r"'\
9.7 Servicing output shaft assembly
9.7.1 Front bearing and output gear
9.7.2 Rear bearing and oil seal
9.7.3 Re-assembling output shaft assembly
10. POWER TAKE-OFF UNIT
33
10.1 To
fit a PTO
unit to an existing gearbox
10.2 To repair an exsiting PTO unit
11. 8° DOWN ANGLE DRIVE UNIT
34
11.1 Retrofitting unit to an existing
gearbox
11.2 Replacement of angle
drive gears
and bearings
12. TIGHTENING TORQUES
36
13. SPARES PARTS LIST 37 r""'\
4

LIST OF ILLUSTRATIONS
Fig. 1 Gearbox cut-away
Fig. 2 Internal layout diagram
Fig. 3 Wiring diagram for neutral safety start device
Fig. 4 Oil pump mounting - anti-clockwise engines
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Oil pump mounting - clockwise engin~s
Hydraulic and lubricating oil circuits
Checking engine flywheel and flywheel housing
Engine and gearbox cooling circuit
Oil cooler connections PRM301
Oil cooler connections PRM301 with power take-off
Oil cooler connections PRM301A with angle drive
Propeller rotation, twin installations
Operating cable entry, twin installations
Piston ring fitting procedure
Shimming procedure
5
Page
2
10
11
11
11
13
16
17
17
17
18
20
20
30
32

1. GENERAL DATA
1.1 Specifications
Gear ratios
1.09:1, 1.459:1,
1.935:1, 2.565 :1 or 2.904:1
Power rating:
1.09 :1 up to 6.38 hp (4.76 kW) per
100 rev/min
1.459:1 up to 6.38 hp (4.76 kW) per
100
rev/min
1.935: 1 up to 6.38 hp (4.76 kW) per
100 rev/min
2.565:1
up to 6.19 hp (4.62 kW) per 100 rev/min
2.904:1
up to 6.19 hp (4.62 kW) per
100
rev/min
Note: All ratings are for guidance and will vary according to application
and duty cycle. Further details available from Newage Transmissions Ltd. or
local distributor.
Input speed:
Up to 3000 rev/min continuous
3600 rev/min intermittent
Input rotation:
Clockwise or anti-clockwise (see section 2).
Output rotation:
Clockwise or anti-clockwise as required (see section 4.1).
Approximate dry weight:
68 Kg (1501b)
(excluding drive coupling, adaptor and cooler).
Additional weight -Power take off: 12 Kg (26.41b)
Angle drive: 17.5 Kg (38.51b)
Oil capacity:
All ratios
Power take off
Angle drive unit
2.5 litres (4.25 pints)
As above ?
3.25 litres (5.5 pints)
4
Note: above capacities do not include oil required to fill the cooling
circuit.
Working oil pressure:
1790 kPa (260lbf/in2 - 18.3 kg/cm2)
Working oil temperature
50°c - 10°c
Maximum permissible temperature 80°C
6

Transmission cooling:
Transmission cooler must be fitted; provision made for connecting unit to
operating valve block.
Capacity of cooler required will vary according to ambient temperature, engine
horsepower and other factors. Suitable coolers are available from Newage
Transmissions Ltd.
Input drive couplings:
Flexible drive coupling for flywheels of 8 in, 10 in and 11. 5 in nominal
diameter to SAE J620C.
Gearcase:
Heavy duty cast iron for use in marine environment, constructed in two halves
for ease of servicing; ribbed internally for rigidity and strength.
0 Input shaft:
28mm (1.1 in) diameter with
16
/32 DP involute spline.
Propeller thrust:
Ahead and astern thrust carried by. output shaft bearings of adequate capacity
for all Newage approved ratings.
Output flange:
152.4mm (6 in) diameter, with 6 holes, 13mm (0.512 in) diameter on 121mm
(4.5 in) PCD.
Installation angle:
The maximum fore and aft installation angle permissible at rest is 17°.
1.2 Application details
llW HP • PRM301 - PLEASURE RATING
1415
200
lJ_
,.o-~~---+-+-+-+-+-- :_::L 1 :_::
T-~"
70
160
f--+-
1,01--
•-~ -+ +-+--JC~/1--+
i
-~--1
~ :~~~
50 so>-v-t-t-+-t-t----t--t-~----t-+--+ ~-+-j--f-~c---1
60 t--++-t--++-t--++-t--++-t--++-t--++-+--
1200 1400 11500 1100 2000 2200 2400 2800 2800 3000
FIE\1/MIN
1) 1.09, 1.459:1 AND 1.935:1
RATIOS
21 2.565:1 AND 2.904:1 RATIOS
THESE RATINGS ARE
FOR PLEASURE CRAFT
OPERATING FOR LESS
THAN 500 HOURS PER
YEAR WITH FULL
THROTTLE USAGE LESS
THAN 10 MINUTES IN
ANY ONE HOUR
kW HP
PRM301 - LIGHT COMMERCIAL RATING
1415 :zoo~~r~~~~~~~~T- -- 7
r------ -r--r--·- + . ·-- '·I
130 ,ao>-
+-+-+-+--+-+ - V/ 2.
110
00
70
60
100
1'0
12
-+-+-+-+-+-+--+-~~-=+-+-++-+-+++---H
/ - -...j
100
V,
80
l'l
60
1200 1400 1100 1100 2000 2200 2400 2800 2800 3000
.. EV/MIN
1) 1.09:1, 1.459:1 AND 1.935:1
RATIOS
2) 2.565:1 AND 2.904:1 RATIOS
THESE RATINGS ARE
FOR FISHING BOATS
AND PLEASURE BOATS
OPERATING LESS THAN
1,500 HOURS PER YEAR
,w
1'0
130
120
110
100
10
80
70
00
50
H•
PRM301 - COMMERCIAL RATING
200
,ooo 1200 ,.ao 1100 ,aoo 2000 2200 :zeoo
REV/MIN
RATING COVERS ALL
RATIOS, FOR WORK-
BOATS OPERATING ON A
CONTINUOUS RATING
FOR MORE THAN 1,500
HOURS PER YEAR
These ratings have been established in order to ensu,e the long and trouble-free life of the gearbox. However, operating conditions can vary widely with
consequential effects on the gearbox and these ratings should therefore be used for general guidance only. If in any doubt, or for particularly arduous duty,
or for applications outside the powers and speeds shown here, please consult the factory or distributor.
7

1.3 Installation details
...
13 SO l
INPUT SHAFT
LENGTH
40 11 57 l
MIN A
73 (2 87 l
""
ADAPTOR
SAE. 2
SAE 3
SAE 4
BORG
WARNER
3143
1123751
n
I LHW d••
, torreff'IOllal
I
oldtPltO.
(0 187 I 203
2"'"'
105€21
I r
76225
76 175 152 4
13001 I t600 I
12 999 I DI.A
DIA
'A' DIMN 'B' DIMN
447.70
(1 7 625") DIA
159 (%")
447 55
(17 620")
15.9 (%")
409.55
(16 124") DIA
409.45 (16 121 ")
362.00 (14250')DIA
15 9 (%")
361 85
(14 245")
28.57
209.55 (8 249") DIA
(1 125")
209.45 (8 246")
TORSIONAL COMPATIBILITY
N.B. MM & (INCHES)
FOR INPUT COUPLING DETAILS
SEE SEPERATE PUBLICATION
889
13'!/'I
INPUT SHAFT
LENGTH
40Jl 57 I
MIN "A
It is extremely important to ensure the torsional compatibility of
the total propulsion system from engine through to propeller since
disregarding this may result in gear chatter, particularly at low
speeds, and in extreme cases component damage or even failure
may occur.
It is the responsibility of the person assembling the drive and
driven equipment to ensure that they are torsionally compatible;
torsional vibration and analysis can be carried out by engine
manufacturers, marine service societies, independent marine
consultants etc. Newage Transmissions Ltd will gladly provide all
relevant information and assistance to help find solutions to
potential torsional problems which may affect the transmission.
8
120.1-
4~··
'"
241.3mm
'%"
...... , •• .-10"• 1106fflffl
4 75"' p.cd
\ 6 HOLES 13 1'3/o, I DIA
EQUALLY SPACED ON A
1206(43/,"JPC0

2. INTRODUCTION
Newage PRM marine transmissions are oil-operated gearboxes of the counter-
shaft type with separate oil-operated multi-disc clutches (which need no
adjustment) for both ahead and astern drive. This design permits full power
to be transmitted in astern as well as ahead, and also allows right-hand or
left-hand propeller rotation in ahead drive, with identical ratios in ahead
and astern.
Both left-hand (anti-clockwise) and right-hand (clockwise) rotating engines
can be accommodated.
Note: when describing engine rotations, face the engine on which the
transmission is to be mounted and describe the rotation accordingly.
Similarly, describe the transmission output rotation as clockwise or
anti-clockwise as seen when standing behind the gearbox output coupling facing
towards the input or engine end of the transmission.
3. CONSTRUCTION
3.1 Gearcase
The gearcase has been kept free from hydraulic pipes, cylinders and associated
components, and the only items mounted externally are the oil pump, hydraulic
control block and operating lever.
A magnetic drain plug is provided at the front of the gearcase; this
removed if required to allow suitable pipework to be connected
hand-operated drain pump.
can be
to a
Connections are provided on the valve block for the oil cooler and pressure
gauge.
3.2 Gear train
The transmission comprises an input shaft assembly, a layshaft assembly and
and output shaft.
The input shaft, which is supported by a taper roller bearing at either end,
incorporates a drive pinion of the required ratio (running on a special self-
lubricating bearing), the forward (when used with a right-hand propeller)
drive clutch assembly, the clutch gear and a hydraulic actuated piston to
operate the clutch.
The layshaft is similarly supported by taper roller bearings and also
incorporates a drive pinion of the same ratio (again running on a special
self-lubricating bearing), the reverse (when used with a right-hand propeller)
drive clutch assembly, a clutch gear of opposite hand rotation to that on the
input shaft, and a hydraulically actuated piston to operate the clutch.
The output shaft runs on amply proportioned bearings, arranged in such a way
that propeller thrust can be satisfactorily absorbed; it also carries the
output gear and the output flange.
9

Internal Layout (with Angle Drive)
Angle Drive
Input Shaft
Internal Layout (Standard)
Fig. 2. Internal Layout
3.3 Gear train - Angle drive
Flywheel
Flywheel
The angle drive unit incorporates a pair of conical involute gears so arranged
that the output shaft runs at an angle of 8° down relative to the input shaft;
it also has the effect of reducing the centre line distance between the engine
crankshaft and gearbox output shaft. The purpose of this is to enable the
main gearbox to be mounted to the propulsion engine in such a way that the
engine can be installed as near as possible to the horizontal whilst
maintaining the required propeller shaft line.
Both input and output shafts are supported on bearings of adequate size for
all Newage approved ratings.
3.4 Valve block
The valve block is located on the top of the gearcase and contains the main
control valve, integral with which is the high pressure valve which controls
the supply to the clutch assemblies. Oil which is surplus to clutch operation
requirements is used for lubrication purposes.
The control valve is fitted with a spring-loaded neutral detent; this provides
a positive neutral position and ensures positive selection of either ahead or
astern drive.
3.5 Neutral safety switch
A neutral safety start switch, which ensures that the engine to which the
gearbox is fitted cannot be started unless the gearbox is in neutral, is
available as an optional extra.
This device is of obvious benefit, since it will help prevent accident or
damage caused by a boat moving ahead or astern on engine start-up in a crowded
marina or other area. ,---.._
10

Forward -
----
Neutral
Reverse ---
3
4
1. Start key switch
2. Starter push switch
3. Neutral safety switch
4. Solenoid/starter motor
Fig. 3. Wiring Diagram for Neutral Safety Start Device.
When used, the switch is located on the valve block (see item Con the parts
list) and should be wired into the starter circuit as shown in Fig. 3.
3.6 Oil pump
A cast iron gear-type pump externally mounted at the rear of the gearcase and
normally driven by the layshaft, supplies oil at high pressure for actuation
of the clutch assemblies, and at lower pressure for lubrication circuits.
When the transmission is used with anti-clockwise engines (looking at the
flywheel) or with clockwise engines when an angle drive unit is fitted, the
oil pump is fitted in its standard position. For clockwise engines, or anti-
clockwise with angle drives the pump is turned through 180° to standard (see
diagrams).
Fig. 4. Oil Pump Mounting - anti-clockwise engines
(or clockwise with Angle Drive)
Fig. 5. Oil Pump Mounting - clockwise engines
(or anti-clockwise with Angle Drive)
Note: Unless otherwise specified at the time of ordering, we will assume
anti-clockwise rotating engine and the oil pump will be mounted accordingly.
0 If a clockwise input rotation is specified when the order is placed, the pump
will automatically be mounted in the appropriate position.
11

4. OPERATING SYSTEM
4.1 Output rotations
With the control lever at the mid-point of travel or neutral position and the
engine running, the splined input shaft and the clutch gear rotate at engine
speed. The clutch gear is in constant mesh with the clutch gear on the
layshaft which is therefore also driven at engine speed, but in the opposite
rotation. Since neither clutch is engaged, the drive pinions do ot rotate.
When the control lever is moved to the 'ahead' position the hydraulic system
is actuated and oil is directed at high pressure to the clutch on the
appropriate shaft; the clutch engages and engine drive is directed to the
forward drive pinion. The pinion turns the gear on the output shaft and the
propeller shaft and propeller are rotated in the direction corresponding to
ahead movement of the vessel.
Similarly, when the control lever is moved to the 'astern' position, the
clutch on the opposite shaft is engaged and drive applied to the reverse
pinion. This turns the output shaft gear in the opposite direction; and the
propeller shaft and propeller rotate in the direction corresponding to astern
movement of the vessel.
Gearbox output rotation
Engine rotation anti-clockwise
With Angle Drive Without Angle
Drive
Lever
Backward J v
Lever
Forward
0 J
Engine rotation clockwise
With Angle Drive
Without Angle Drive
Lever Backward G J
Lever Forward
J
'--'
Note:
(i)
Rotations are as seen looking from the propeller forward to the
gearbox.
(ii)
Anti-clockwise engines are by far
standard gearbox build therefore
input.
4.2 Hydraulic system
the most common, and the
assumes an anti-clockwise
Oil is pumped from the gearbox sump through the internal supply pipe and is
delivered to the control block, which incorporates a high pressure valve to
ensure that the correct operating pressure is maintained,
12

When the operating lever is moved, oil is delivered under pressure to a feeder
on either the input shaft or layshaft and thence to a piston which actuates
the appropriate clutch for either ahead or astern drive.
Oil in excess of that required for hydraulic actuation is used for lubricating
the gearbox.
4.3 Lubrication
l_____':___J SUMP
OIL
COOLER
"
11 II
)ii( )i!l
11 11
~ b
ANGLE P.T.O.
DRIVE LUBE
LUBE.
HIGH PRESSURE LINE TO
FORWARD CLUTCH (ENGAGED)
•••••- HIGH PRESSURE LINE TO
REVERSE CLUTCH (DISENGAGED)
LUBRICATING CIRCUIT
Fig. 6. Hydraulic and Lubricating Oil Circuits.
Oil for lubrication purposes is also delivered via the internal supply pipe to
the control block. Irrespective of whether ahead or astern is engaged oil is
diverted from the discharge side of the pressure relief valve to an external
oil cooler. After passing through the cooler, the oil is directed through
channels on the valve block to the feeders and thence through the layshaft and
drive shaft to lubricate the clutch assemblies.
13

4.4 Approved oils
APPROVED LUBRICANTS - PRM MARINE GEARBOXES
Company Ambient Temperature Ambient Temperature Ambient Temperature
Below QOC
ooc -3Q0C
Above 3QOC
BP
BP Vanellus M2050
BP Vanellus M20-50 BP Vanellus M20-50
Castro! GTX
Castro! GTX
Castro! GTX
CastroI or
or or
Deusol CRB 20W/50 Deusol CRB
20W/50 Deusol CRB 20W/50
Century Supreme 20W/50 Century Supreme 20W
/50
Century or
or
Century Supreme 20W/50
Centlube Supreme 1 OW /30
Centlube Supreme 10W/30
Chevron Delo 100 1 OW
Chevron Delo 100 20W /20 Chevron Delo 100 30
Chevron or or
or
Chevron Delo 200 1 OW
Chevron Delo 200 20W/20 Chevron Delo 200 30
Conoco 20W /50
Conoco 20W /50
Conoco or or
Conoco 20W/50
Conoco HD lOW/30
Conoco HD l0W/30
Q Motor Oil 0
Motor Oil
Duckhams Fleetol
Multilite
or
or
Fleetol Multi-V
Fleetol Multi·V
Elf
Cougar 15W /30
Cougar 15W/30
Cougar 15W/30
Esso Superlube
Essa Superlube Essolube HDX Plus 30
or
or or
Essa
Essolube HDX Plus 10W-30 Essolube
HDX Plus 30
Tromar HD30
or or or
Essolube XD-3 10W
Tromar HD30
Essolube XD-3 30
Fina Dilano 20 Fina Dilano 30 Fina Dilano 40
Fina
or
or or
Fina 20W/50
Fina 20W/50 Fina 20W/50
G.M.O. XHD l0W/30 G.M.O.
XHD l0W/30 G.M.O. XHD 10W/30
Gulf
or or
or
G.M.O. XHD 10W G.M.O.
XHD 20W/20 G.M.O. XHD 30
Mobil Super 15W-50 Mobil Super 15W-50 Mobil Super 15W-50
or or
or
Mobil
Delvac Special 10W-30 Delvac Special l0W-30 Delvac Special 10W-30
or or or
Delvac Super 15W-40 Delvac Super 15W-40 Delvac Super 15W-40
Shell Super Motor Oil Shell Super Motor Oil Shell Super
Motor Oil
Shell
or or or
Rotella TX 20W/40 Rotella TX 20W/40 Rotella TX 20W/40
Chatsworth 10 Engine Oil Chatsworth 20 Engine Oil Chatsworth 30 Engine Oil
Silkolene or
or or
Permavisco 20W650 Engine Oil Permavisco 20W/50 Engine Oil Perrnavisco 20W/50 Engine Oil
Ursatex 20W-50 Ursatex 20W-50 Ursatex 20W-50
Texaco or
or
or
Ursa Extra Duty 20W-40 Ursa Extra Duty 20W-40 Ursa Extra Duty 20W-40
GTS GTS GTS
Total
or or or
HD2.M 20W/50
HD2 M 20W/50 HD2.M 20W/50
Super HPO 10W
XLD 15W 50
Valvoline or
XLD 15W 50 or
HOS HOM 10W Grades All Climate 20W-50
Customers wishing to use any oil not listed above should send the relevant details to Newage for prior
approval. Failure to do so may result in the forfeiture of warranty cover since no claims under warranty will
be entertained if oil of the wrong specification is used. ~
14

5. INSTALLATION
5.1 General
The Newage PRM301 marine gearbox is supplied with a choice of adaptor plates
to SAEZ, SAE3, or SAE4 specifications thus allowing the transmission to be
mounted to engine flywheel housings of equivalent specification.
Drive is transmitted from the engine to the gearbox via a flexible input
coupling which bolts to the engine flywheel with the gearbox input shaft
inserted into its centre.
These components enjoy a degree of torsional flexibility, the purpose of which
is to damp down engine torisonal or cyclic vibrations and prevent them being
passed to the transmission.
The strongest engine vibrations are usually those caused by firing in the
cylinders; diesel engines which have high compression ratios, usually generate
stronger vibration pulses than petrol (gasolene) engines; and it is often the
case that of two engines of roughly equivalent size, the one having the
greater number of cylinders will tend to run more smoothly than the one with
fewer cylinders, although this is by no means always the case.
In all marine installations, correct alignment
misalignment can cause noise, vibration and
strongly recommend that all the procedures
carefully followed.
is of the utmost importance -
premature failure and we
detailed in this manual are
Note: It is particularly important to ensure the torsional compatibility of
the complete propulsion system from engine through to propeller since
disregarding this may result in gear noise at low speed operation and in
extreme cases damage or failure of components.
Newage Transmissions Ltd. will provide all possible information and assistance
to help find solutions to potential torsional problems, but it is the ultimate
responsibility of the person assembling the drive and driven equipment to
ensure that they are torsionally compatible.
5.2 Checking the engine flywheel housing
Attach a dial test indicator, calibrated in units of 0.001 in. (0.025mm) or
smaller, to the flywheel so that the measuring stylus of the indicator is
perpendicular to the bore of the flywheel housing (bore A on Fig. 7). Rotate
the flywheel and check the deviation on the indicator over one complete
revolution: this should not exceed 0.006 in. (0.152mm) total indicator reading.
With the dial test indicator still attached to the flywheel, re-position the
stylus so that it is perpendicular to the face of the flywheel housing (face B
on Fig. 7). Rotate the flywheel and check the deviation over the one complete
revolution; again, this should not exceed 0.006 in. (0.152mm) total indicator
reading.
5.3 Checking the engine flywheel
Attach a dial test indicator, calibrated to 0.001 in (0.025 mm) or less, to
the engine flywheel housing so that the measuring stylus of the indicator is
perpendicular to the bore of the register in the flywheel (bore Con Fig 7).
Rotate the flywheel through one complete revolution and note the deviation,
this should not exceed 0.005 in (0.125mm) total indicator reading.
15

With the dial test indicator still attached to the flywheel housing,
reposition the stylus so that it is perpendicular to the face of the flywheel
register (D on Fig 7). Rotate the flywheel through one complete revolution
and note the deviation, this should not exceed 0.005 (0.125mm) total indicator
reading.
Flywheel housing
Bore C Bore A
Fig. 7. Checking engine flywheel and flywheel housing.
5.4 Mounting the gearbox to the engine
1. Mount the flexible input coupling to the flywheel, using an alignment
mandrel if available, and bolt it to the flywheel using the holes
provided. Where components to SAE standard are used, the outside diameter
of the drive plate or coupling should be a close fit in the register on
the flywheel.
If a mandrel is not available, tighten the mounting bolts, just
sufficiently to prevent free movement, assemble the gearbox to the
coupling, and rotate the engine two or three revolutions by hand to align
the plate. Tighten up two or three opposite bolts, using the inspection
window provided on the gearbox adaptor flange.
2. Remove the gearbox and fully tighten the flexible input coupling bolts.
3. Taking care to ensure correct alignment, mount the adaptor flange to the
front of the gearbox.
4. Offer up the gearbox and adaptor to the input coupling and engine flywheel
housing at the correct angle of inclination to obtain the shaft offset and
insert the gearbox input shaft into the centre of the coupling (it may be
necessary to rock the shaft slightly to ensure that the shaft enters).
Press the assembly fully into position, align the mounting holes in the
adaptor flange with those on the flywheel housing and bolt securely.
5.5 Oil cooler
All Newage PRM301 gearboxes must be fitted with an oil cooler to maintain
correct working temperatures. To permit a suitable cooler to be fitted, two
3
/8 in. BSP connections are provided on the valve block, and these are
blanked off with '"Redcap'" seals on delivery from the factory.
The gearbox oil cooler is normally mounted on the gearbox adaptor flange or
the bulkhead of the boat, and then connected into the cooling system on the
engine; one method of arranging the engine and gearbox cooling circuit is
shown below.
16

Heat Exchanger and Header Tank
I
~--·
Fig. 8 Engine and gearbox cooling circuit
5.5.1 PRM302 standard gearbox
Remove the "Redcap" seals from the valve block and connect, via suitable
hoses, to inlet connections on the oil cooler, which can then be incorporated
into the engine cooling system as outlined above.
'1'
L
ti
•. \,,
,.
Fig. 9 Oil cooler connections
5.5.2 PRM302 with power take-off
Oil returned from the cooler to the valve block is first passed through the
power take-off unit to provide lubrication and the method of connecting the
cooling system is as follows:
a) remove "Redcap" seals from the valve block.
b) connect the valve block outlet to oil cooler inlet
c) connect the oil cooler outlet to the PTO inlet.
d) complete the circuit by connecting the PTO outlet to the valve block inlet.
The oil cooler can now be connected to the engine cooling system as outlined
above.
17
Fig. 10 Oil cooler connections
PRM 302 with power take-off

5.6 A1ignment to propeller shaft
Alignment between the propeller shaft and the mating flange on the gearbox
output shaft is extremely important since excessive vibration and stress
leading to damage and perhaps even failure can occur if correct alignment is G
not achieved.
It is generally considered preferable to couple the propeller shaft direct to
the gearbox output flange using a rigid coupling particularly in the majority
of boats whose hulls have sufficient rigidity as not to allow flexing in heavy
sea conditions, which could cause the engine and transmission to shift in
relation to the propeller shaft.
The two main conditions when a flexible coupling should be used are:
i) in boats whose hulls are insufficiently rigid to prevent the flexing
referred to above, and
ii) in cases where the engine is mounted on flexible mounts.
In both instances, the flexible coupling will isolate engine vibration or
other movement from the propeller shaft, thereby enabling the correct
alignment to the propeller shaft and the stern tube to be maintained.
Whether a solid or flexible coupling is used, it is extremely important that
the following points are carefully checked:
i) the coupling should be a tight press fit on the shaft and the keyway
accurately made to the correct size, and
ii) the two halves of the coupling should be carefully aligned. This should
be done by bringing the two flanges close enough together so that a feeler
gauge can be used to check the vertical and horizontal alignment.
Since the propeller shaft line is normally fixed in the boat, alignment is
usually obtained by adjusting engine mount shims on the mounts themselves.
Note: Whenever possible, the engine and gearbox should be installed whilst
the hull is afloat, otherwise there is a danger of the hull distorting because
of insufficient support over its surface. If the engine and transmission are
fitted before the hull is in water, the installation should be very carefully
re-checked for alignment after launching.
5.7 Installation angle
The transmissions should normally be installed so that the maximum fore and
aft angle relative to the water line does not exceed 17° with the boat at rest.
18

Whether a solid or flexible coupling is used, it is extremely important that
the following points ,are carefully checked:
i) the coupling should be a tight press fit on the shaft and the keyway
accurately made to the correct size, and
ii) the two halves of the coupling should be carefully aligned. This should
be done by bringing the two flanges close enough together so that a feeler
gauge can be used to check the vertical and horizontal alignment.
Since the propeller shaft line is normally fixed in the boat, alignment is
usually obtained by adjusting engine mount shims on the mounts themselves.
Note: Whenever possible, the engine and gearbox should be installed whilst
the hull is afloat, otherwise there is a danger of the hull distorting because
of insufficient support over its surface. If the engine and transmission are
fitted before the hull is in water, the installation should be very carefully
re-checked for alignment after launching.
5.7 Installation angle
The transmissions should normally be installed so that the maximum fore and
aft angle relative to the water line does not exceed 17° with the boat at rest.
In the case of the Newage PRM301A (angle drive) the transmission provides 8°
down angle on the output shaft; it also has the effect of reducing the centre
distance between the engine crankshaft and the gearbox output shaft, and
enables the engine to be mounted nearer to the horizontal than would be the
case with conventional in-line or drop centre transmissions. This has the
effect of reducing the overall height required for installing the engine and
will also help to prolong engine life.
5.8 Twin installation
The rotation of a propeller, even in a single engine installation,
have a slight "turning" effect on the handling of the boat, but
normally be corrected with very slight adjustments on the rudder.
tends to
this can
In twin installations, the turning effect on the handling of the boat will be
much more pronounced if both propellers rotate in the same direction. It is
therefore desirable that "handed" (i.e. counter-rotating) propellers be
fitted, and it is for this reason that PRM gearboxes are capable of providing
either hand of output rotation at any of the available gear ratios.
It is also preferable for the starboard (right-hand) propeller to rotate
clockwise and the port (left-hand) anti-clockwise rather than the other way
about since in the latter case, when the propeller blades are at the lowest
point of their rotational arc they tend to create a vacuum which affects the
other propeller by reducing the flow of water to it; furthermore, when the
boat is making a tight turn with one gearbox in "ahead" and the other in
"astern", the thrust side of one propeller will be acting diametrically
opposite to the other one, causing the boat to be deflected off line and thus
delaying completion of the manoeuvre.
When connecting remote control units for twin engine/gearbox installations; it
should be remembered that forward operation of the gearbox operating lever
will produce output rotation as engine (generally left-hand, or anti-
clockwise).
19