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HANDBOOK
FOR
25-30 H.P.
ROLLS-ROYCE CAR
CHASSIS SERIES
(In order of Issue)
GUL GRM GAN GRO GRP GAR
GYL GXM GWN GHO GMP GGR
GHL GGM GUN GMO GLP GZR
Liable to alteration without notice
PRICE £1. 5. 0
PUBLISHED BY
ROLLS-ROYCE, LIMITED
DER BY, CREWE,
AND AT 1 4 AND 15, CONDU IT STREET, LONDON
CONDENSED E D I T I ON
NO. XVII
Page 2
Front Axle Control
Front Hydraulic
Damper
Dynamo
Carburetter
Crankcase Oil Filter
Chassis Oil Pump
Starter Motor Pinion
Housing
Clutch Pit Inspection
Cover
Servo Motor
Grouped Instruments
Universal Joint
Foot Brake Equaliser
Brake Rods
Brake Ropes
Spring Gaiter
Universal Joint
Rear Axle Filling
Plug
Fuel Tank Filler
Fig.1. - Plan View of Chassis.
Front Brake
Adjustment
Steering Pivot
Cross Steering Tube
Side Steering Tube
Carburetter Air
Silencer
Steering Box
Distribution Box and
Output Regulator
Fuel Pumps
Speedometer Drive
Accelerator Pedal
Starter Switch
Switch Box
Hand Brake Lever
Gear Lever
Strangler Control
Ignition Control
Throttle Control
Hand Brake
Equaliser
Rear Hydraulic
Damper
Battery
Rear Brake
Adjustment
Fuel Gauge Unit
ROLLS-ROYCE LIMITED.
Londo n Off ice a nd Showroom :
14 & 15, CO ND UI T STREE T, LONDON, W.
TEL EGRAMS : “RO LHEA D REG . LO NDON.”
TEL EPHONE S: MAYFA IR 62 01 ( 7 line s)
COD ES USE D: A B C (5 TH EDI TION) , BE NTLEY ’S, MARCON I
MOT OR T RADE , WEST ERN U NION
Mai n Ser vice Stati on:
Hythe Road, Willesden, London N .W. 10
TEL EGRAM S: “ SILVAGOST, WESPH ONE, LONDO N”
TEL EPHON E: L ADBRO KE 24 44
Cre we Re pair Depôt :
Pym’s Lane, Crewe
TEL EGRAM S: “ ROYCR U, CR EWE”
TEL EPHON E: C REWE 3271 (10 LINES )
Aut horis ed Pa ris S ervic e Sta tion:
Franco-Britannic Autos Lt d.
25 Rue Paul Vaillant Couturier, Levallois, Se in e
TEL EGRAM S: “F RANCO BRIT-LE VALL OIS-P ERRET-F RANCE ”
TEL EPHON E: PE RIERE 60-2 4
Page 3
TH E
SE C RET O F SU C CESS F UL
RU N NING .
Before a Rolls-Royce chassis is sold it is very
carefully teste d and adjusted by experts.
It will run best
if no attempt be made to unnecessarily interfere with
adjustments.
An owner would do well to instruct his driver as
follows:-
Lubricate effectively, in strict accor dance with the
advice given in this Handbook, and do not neglect any
part.
Inspect a ll parts regularly, but take care not to alter
any adjustments unless rea lly necessary.
CONTENTS
PAGE
SERVICE FACILITIES fOR ROLLS-ROYCE CARS ... ... ... 4
LEADING PARTICULARS OF CHASSIS ... ... ... ... 5
CHAPTER I.- STARTING THE ENGINE AND DRIVING THE CAR 7
Starting the Engine - Ignition Control-Throttle Control-Change-
over Switch for Fuel Pump- Fuel Gauge-Gear Changing-Controllable Shock Dampers-Lighting Control and Switch-Radiator
Shutters-Overheating-Fitting of Snow Chains.
CHAPTER II.- PERIODIC LUBRICATION AND ATTENTION ... 13
Lubricants Recommended-Capacities-Centralised Chassis Lubri-
cation System-Daily Maintenance-Every 2,000 miles-Tappet
Adjustment-Every 5,000 miles-Every 10,000 miles-Every
20,000 miles-Care of Wheels and Hubs-Replacement Tyres-
Balancing Road Wheels.
CHAPTER III.- FUEL SYSTEM ... ... ... ... ... ... 30
The Fuel System - Fuel Pumps - Petrol Filters - Action of the
Carburetter-Accelerator Pump-Economiser Jet-Strangler Con trol for Starting - Adjustment of Carburetter-Setting of Idling
Adjustment-Diagnosis of Faults-Float Feed Mechanism-”Hot
Spot”-Air Silencer and Cleaner.
CHAPTER VI.-ADJUSTMENT OF BRAKES ... ... ... ... 40
General-Adjustment of Foot Brakes-Adjustment of Hand Brakes
-Adjustment of Servo.
CHAPTER V.- THE CLUTCH ... ... ... ... ... ... ... 45
Adjustment of Clutch.
CHAPTER VI.- COOLANT SYSTEM ... ... ... ... ... 46
Coolant Pump-Radiator Shutters-CoolantLevel-Frost Pre-
Cautions-Fan.
CHAPTER VII.- ELECTRICAL SYSTEM ... ... ... ... ... 50
General-Battery-Battery Ignition-Sparking Plugs-Electrical
Fault Location
GUIDE TO MAIN SERVICE STATION ... ... ... ... ... 55
GIUDE TO CREWE SERVICE STATION ... ... ... ... ... 56
Page 4
SE RVIC E FA C I LIT I ES
FO R ROL L S-R O YCE C ARS
Our inte re st i n y our Roll s- R oyce ca r d oe s n o t c e ase
when yo u tak e d e live ry of the ca r. I t i s our a mb itio n t h at
ever y p ur c has er o f a R olls -R oyce car sha ll c o n t inue to be
more t han sa tisf ie d.
Wi t h t h is end in vie w, we ha v e a p paoi nt e d S pec ia l
Reta il ers thr ou ghou t t h e w orld , w h o h a ve esta bl ishe d
prop er ly
equi pp ed Ser vi c e Stat io ns, sta ffed by men wh o h a ve
been s peci al ly t ra ined i n se rv icin g Roll s- Royc e c ars .
In addi ti on, on t he s taff of Rol ls -Roy ce Li m ited , th e r e
are ex p e rts w h o se sol e d u ty it is t o m a int ai n c ont ac t with
the Spec ia l R e t aile rs , a n d t h e y a r e a v a i lab le a t a ll t im es t o
be c a lled in f o r c o n sult at ion o n a ny m at ters aff ec ting you r
car.
If, th er efor e, y o u s h ould r e q uire a n y a s s ist an c e,
we a s k t h a t y o u s ho uld i m med ia t ely c onta ct o ur n ea rest
Spec ia l Reta il er, w h o will o n l y be too p l e ased t o p l ace hi s
faci li ties a t yo ur dis po sal. If ne c essa ry h e w ill ca l l i n f or
cons ul tati on o u r e x pert in th at a r e a. It is e a r nest ly h o p ed
that this a rran ge ment w ill p r ove o f mu t u al be n efit , as w e
will th u s b e k e p t i n c onst an t t o uch wit h o u r C u s tome rs , w ho
may be spa re d t h e t r o uble of a lon g jo u r ney to one of ou r
Comp an y’s Ser vi c e St at ions .
In t h e ev e nt o f it bei ng mo r e co n veni en t to ca l l on us
dire ct fo r ass is tanc e,
our M ain S e rvic e Sta ti on at Hy th e
Road , W i lles de n, L o n don N . W.10, and t h e o n e at our
fact or y a t Crew e, wil l be re ady at al l time s to h e l p. ( Se e
maps a t en d of H an dboo k. )
LE A DING PART ICU L ARS O F C H ASSI S .
Engine .
Six cy lind er s, 3½ ” ( 89m /m . ) bo re , 4½” ( 11 4 m /m.) s trok e, 4.25 7 c .c.,
29.4 H. P. on R .A .C. ra ti ng. Un it c onst ru ctio n w ith ge ar box, mo n oblo c
with de t a cha bl e h ead,
over he ad val ve s o pera te d b y p ushr od s, Roll sRoyc e b a t tery ig n i tion wi t h a u toma ti c a d vanc e, f o rced lu b r icat io n,
cool in g by p ump ci rcul at ion, d own- dr augh t carb ur e tte r.
Electr i c a l E q u i pment.
Tw e l ve-v ol t R o lls- Ro yce dyna mo , s t arte r m ot or, a nd o t h er u nits .
Appr ox imat el y 60 a mper e- hour b atte ry.
Clutch .
S in gle dr y pl at e.
Gearbo x .
F ou r-s pe ed a nd rev er se, si de c on trol ; spee do mete r a nd br a ke s er vomoto r driv es inc or pora te d.
Re a r A x l e .
Hy ph oid g ea rs, f ul l flo at ing, ro sd wh e e l s en ti r ely c a r r ied on axle
tube s.
Brake s .
Int er nal ex p andi ng , ser vo oper at ed, on a ll f ou r whee ls . Ind ep ende nt
hand b rake o pera ti ng o n rear w heel s.
Ro a d S p r i n gs.
Se mi -ell ip tic, f ront a nd r ea r.
W h e els.
Whee ls wi t h 19 ” we l l-ba se ri m s an d Du n l op C ty pe ty r e s, s ize
6.00 -1 9 ar e fitt ed .
Page 5
W h e elbase.
132”
Tr a c k .
56 5 /1 6”
Tu r ni n g C i r c les.
Cent re of ou tsid e fron t tyre : R.H. , 47’ 5” d i ame te r ;
L.H. , 42’ 0” d i ame te r
Ov e r w i n g s above c e n t r e l ine of f ro n t axle:-
R.H. , 48’ 6” d iame te r ;
L.H. , 43’ 1” d i ame te r
Fuel T ank.
Eigh te en ga llon s cap ac ity, at rea r of c h assi s. Su pply b y el e ctri c
pump s.
Chassi s L u b r i c ation.
Cent ra lise d syst em , pe da l-op er ated p ump.
We i g h t .
Chas si s c o m plet e with tyr es , b a t tery , f u e l, o i l a n d wat er, b u t
excl ud ing s pa re whe el ,
lamp s a nd oth er a cce ss o ries - a p prox im atel y
2,93 0 lbs.
STARTING THE ENGINE AND DRIVING THE CAR 7
CHAPTER I
Starting the Engine and Driving the Car
S
tarting the Engine - Ignition Control-Throttle Control - Change over Switch for Fuel Pump - Fuel Gauge - Gear ChangingControllable Shock Dampers - Lighting Control and Switch - Radiator
Shutters - Overheating - Fitting of Snow Chains.
Starting the Engine.
To start the engine, rst check that the change gear lever is
in neutral, set thumb lever on instrument board to Start,
switch on
the ignition by turning the right-hand thumb lever on the switchbox
to I.& C. - on later models to On- retard the ignition about onequarter from top of quadrant, and set hand throttle lever at bottom
of the quadrant. Now depress the starter button rmly and to its full
extent.
As soon as possible after the engine starts, set the hand throttle
lever a little over half-way up its quadrant and move thumb lever to
Run. At the same time, advance ignition hand lever to the top of
its quadrant.
When making a start with a warm engine, leave thumb lever at
Run and
set hand throttle lever a few notches up its quadrant and
ignition lever fully advanced.
The action of switching on the ignition also switches on the electric
fuel pumps,
and a few pulsations of the latter may then be heard.
An appreciable pause must be made between the operations of switching
on the ignition and depressing the starter button, especially when making
a start from cold. This is necesary in order to give time for the pumps to
ll the oat chamber of the carburetter.
A small red warning lamp on the instrument board will be illuminated when the ignition is switched on,
but will be extinguished when
the engine speed is sufcient to cause the cut-out contacts to close.
On no account should the accelerator pedal be “jiggled” when
using the starter motor-or indeed at any time. Such movement brings
into action the accelerator pump provided on the carburetter and
causes liquid fuel to be injected into the carburetter.
The thumb lever control on the instrument boardis arranged to
provide a suitably rich mixture for starting from cold, and it should
only be turned to Start under these conditions. Normally, it should
stand at Run. It is not intended for varying the mixture strength
under running conditions.
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8 ROLLS-ROYCE 25-30 H.P. CAR
It will be observed that when starting from cold the hand throttle
lever is set in the closed position, i.e., at the bottom of its quadrant. The
reason for this is that there is an interconnection between the throttle lever
on the carburetter and the instrument board thumb lever which causes
movement of the latter to Start, to open the throttle simultaneously the
required amount.
As soon as the engine starts, the hand ignition control may be
fully advanced.
When starting the engine for the rst time in the day it is a good
plan to form the habit of depressing the chassis oil pump pedal once at
this stage. Subsequently it should be depressed once every 100 miles. If
the car is to be driven only a few miles, however, half a pumpful will be
sufcient at the rst starting.
When the engine is cold a high oil presure will be shown on the
gauge, due to the greater viscosity of the oil at low temperatures. The
pressure will fall, however, as soon as the oil becomes warmer.
A starting handle is carried in the tool kit. In the event of it being
used, it should be removed afterwards from the bracket and returned to
the tool kit. The ignition must be fully retarded when starting by hand.
Ignition Control.
When driving the car, the ignition lever should normally be fully
advanced.
The actual amount of
advance is controlled partly by
hand, as previously indicated, and partly automatically by means of
a centrifugal
governor operating on the distributor drive.
This is
capable of meeting 90 per cent. of the conditions due to varying road
speeds,
leaving only extreme conditions to be met by moving the
hand control on the steering wheel.
Throttle Control.
Under normal running conditions, the hand throttle control should
be carried right back in the closed position. An adjustable stop is
provided on the carburetter for the throttle lever, which is so adjusted that
the engine will idle reliably in these circumstances when the accelerator
pedal is released.
Change-over Switch for Fuel Pump.
In addition to the ordinary ignition switch, which also switches
on the pumps, a change-over switch is arranged on the instrument board
in order to provide a ready means of checking that each half of the
double fuel pump is operating correctly.
Normally, the switch would stand at Both when both halve
s of
the pump should be working.
STARTING THE ENGINE AND DRIVING THE CAR 9
Occasionally a few miles’ running should be done with the
switch moved to “A” position, which cuts out one half of the pump.
At moderate throttle openings, no difference in running should be
noticeable. The test should then be repeated with the switch in the “B”
position, which cuts out the other half and switches on the half rst cut
out.
In the circumstances described, failure or defective running of the
engine only evident when the switch is on one side, indicates that one
half of the pump is faulty, and Messrs Rolls-Royce Ltd., or one of their
Special Retailers, should be consulted at the earliest opportunity.
The connections of the change-over switch are shown in the
Electrical Wiring Diagram, Fig. 23.
Fuel Gauge
The electrical fuel gauge on the instrument board is graduated
to register the total amount of fuel in the main tank. The gauge is
inoperative when the ignition is switched off.
Special contacts carried by the tank unit cause the green warning
lamp to light when only about two-and-a-half gallons of fuel remain in
the tank.
Gear Changing
The position of the gear lever for each of the four speeds and
the reverse is shown in Fig.*2.
When
reverse is required,
the top of the
lever must be depressed. This
releases a catch and enables the
lever to be moved into the gate
marked R.
A special synchronising device
is provided in the gearbox to
facilitate the changes between top
and third gears and from second
to third. All that it is possible to
ensure by such a synchronising
mechanism, however, is that the
gear members to be engaged cannot
be brought together until they are
both rotating at the same speed.
It does not sychronise the engine
and clutch shaft speeds. This must
be done by the driver before reengaging the clutch, otherwise
there will be an unpleasant jerk,
causing unnecessary wear and tear
of the clutch and strain on the transmission.
Page 7
10 ROLLS-ROYCE 25-30 H.P. CAR
It is necessary to depress the clutch pedal fully when changing
gear. The gear lever should then be moved gently into the required
gear position and, before re-engaging the clutch, the engine should
be speeded up when changing down, or allowed to slow down when
changing up, so that its speed shall suit the car speed on the required
gear.
Other changes, namely, those both up and down between second
and rst and that down from third to second, must be made in the usual
manner, double clutching when changing down.
Controllable Shock Dampers.
In order to provide comfortable riding at all speeds, a centrifugally
-controlled pump is tted which causes the damper loadings to increase
with the road speed. In addition, there is a lever above the steering
wheel, marked Riding Control, the effect of which is superimposed
on that of the governor.
For ordinary town work or touring with moderate speeds, it will
be found that the damper loadings as set by the governor are adequate
when the hand lever is either at Soft or mid-way. On the other hand,
at high speeds or with heavy loads, improved riding comfort will be
obtained by moving the lever to Hard.
Lighting Control and Switch
Two types of switchbox are tted, those on the earlier models
are as under: Carried on the right-hand end of the instrument board, this unit
includes: (a) Lamp switch.
(b) Ignition and charging switch.
(c) Push-button for instrument board lamps.
(d) Socket for inspection lamp plug.
(e) A lock which can be locked and the key withdrawn with
the switches in only two positions: (1) When both ignition and lamp switches are at the
off position.
(2) When ignition is at the off position, but the lamp
switch is at the
S and T position.
Do not try to lock the switch in other positions.
The switches
(a) and (b) are operated by thumb levers, and the
various combinations controlled by each are clearly indicated by the
letters as follows:-
OFF ... ... No circuits in action.
S and T ... Side and tail lamps on.
H, S and T ... Head, side and tail lamps on.
STARTING THE ENGINE AND DRIVING THE CAR 11
I and C ... Ignition on, fuel gauge and fuel pumps on, and
connections closed to enable the dynamo to
charge the battery .
On the later models a modied form of switchbox is provided
incorporating a master switch.
The unit is carried on the right-hand end of the instrument board
and includes:-
(
a) Master switch and lamp switch combined.
(b) Ignition switch.
(c) Push-button switch for starter motor.
(d) Socket for inspection lamp plug.
(e) A lock which can be locked and the key withdrawn either: (i.) When the master switch is in the “Off” position;
or (ii.) When the master switch is in the P.L. (“parking
lights”)position;
No attempt must be made to lock the switch in other positions.
With the master switch in the “off” position, most circuits and
accessories such as horns, starter motor, ignition, windscreen wiper,
instrument lamps etc., are rendered inoperative. Movement of this
master switch to the “on” position renders these accessories available.
The various combinations conrolled are clearly indicated as
follows:-
OFF ... ... All circuits off, except for clock.
ON ... ... Accessories available
S and T ...
Side and tail lamps on and accessories available.
H, S and T ... Head, side and tail lamps on and accessories
available.
P.L. ... ... “Parking lights”, side and tail lamps on, acces-
sories off.
A separate ignition switch is provided, marked ON and OFF
Normally, this switch can be left in the “on” position, and the switching
to start and stop the engine can be carried out on the master switch.
No independent charge position is provided owing to the presence
of the output regulator. Whenever the master switch is on, connections
are made which cause the dynamo to charge the battery through the
regulator, as elsewhere described.
Radiator Shutters.
The radiator shutters are controlled automatically by means of a
thermostat in the upper radiator tank.
A themometer is provided on the instrument board to indicate
that the shutters are operating properly and that there is no shortage of
coolant.
The hand-operated ventilators on the sides of the bonnet should
be left open in hot weather.
Page 8
12 ROLLS-ROYCE 25-30 H.P. CAR
Overheating.
If on long ascents which call for full throttle, “boiling” should
occur
due to abnormal conditions of atmospheric temperature, and,
or, following winds, etc., it is preferable to change into a lower gear
and reduce the throttle opening.
Adjustment of the fan belt may be necessary, and this should
receive attention.
Fitting of Snow Chains.
In the event of snow chains being necessary, they should be
tted to the rear wheels only.
A Parsons’ chain, known as the “Special Rolls-Royce Type”, is
available. It is recommended that these be obtained through Messrs.
Rolls-Royce Ltd., or one of their Special Retailers, in order to ensure
the supply of the correct type.
When tting these special chains, it is essential to commence
by fastening the one hook on the inside of the wheel and always to
take up the adjustment on the outside, where two fastening clips are
provided. The tensioning springs which are supplied to go on the
outside of the wheel must always be tted.
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