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Service Bulletins 1954-57
Compiled by John Elmgreen, Sydney, NSW Australia 5-96 ©John Elmgreen
Comment notes added by Bruce Carnachan and Rob Reilly
Not for reproduction



XK140 era Service Bulletins, Nov 54 - May 57:

SB 156 - Nov 54: Advance servicing information: 3 large pages of basic information.

Selected items: standard compression 8:1 (7:1 alternative - note: no 9:1 mentioned at all). Valve clearances 004/006. Standard rear axle ratio 3.54 (high 3.31, overdrive 4.09). Rear spring gaiters fitted (lubricate every 2,500 miles). Page of recommended lubricants (? check with ID plate information?).


SB 158 - Nov 54: Tappet grading - discontinued: Only one grade henceforth supplied.


SB 159 - (no date): Drive gear setscrews: Very late XK120s (661172/675192, 669193/681481, 667279/678417 on) had larger headed drive gear setscrews (11/16" across flats vs 9/16").


SB 161 - Feb 55: Oil pump & seal: XK140 G 1908 onwards had a rotor type oil pump and

circular oil seal at front end of crankshaft fitted. Oil pressure valve now fitted in the filter head. The SB contained a long list of parts affected by the changes, including (oil filter) canister now 46160, dipstick now C8781, sump now C8592. Also there was a different cylinder block number, C8610, timing cover C8614, and generator bracket now C8619, front engine mounting C8783-4, and the whole oil pump.


SB 163 - Feb 55: Identification of XK140 models: Chassis numbers etc explained (per

commission plate). All set out in detail what chassis numbers meant etc. Notes that chassis number was stamped on chassis frame left hand side member "above rear engine mounting bracket" - therefore not on the front cross member as it had been on the XK120. Engine no. on back of head and above oil filter. C type cylinder head painted red between the valve covers and has a "Jaguar Type C" badge on each cover. Gearbox no. was stamped on a shoulder at left hand rear corner of gearbox, AND on the rim of the core plug aperture in the top cover. JL or OSL prefixes (no difference noted) and E suffix indicated overdrive. Body no. on a plate attached to the left hand side of the scuttle under the bonnet.


SB 164 - Feb 55: Tuning data - XK120: Table set out detailed info re carburetor needles, and ignition system settings (not reproduced here).


SB 167 - Mar 55: Thermostat: Change of thermostat from engine G2841, plus certain individual engines prior to that number. New thermostat was C3731/1 which had the number 43570/5 stamped on it and an opening temperature of 73 deg C. The earlier one was 43570 and opened at 60 deg. (as stamped on the base). The later type was also fitted as standard to the Mk VII. The new thermostat was to be fitted where there were symptoms of cold running (e.g about 55 deg) and spitting back from the carbs on full throttle acceleration from about 2000 rpm in top gear.

Oil: multi grade engine oils: Refers to introduction of Shell multigrade oil (Shell X-100 10W/30 and B.P. Special Energol (Visco-Static). Oils fully detergent.

Drive gear lockstraps: XK140 overdrive models: 4.09 ratio, had flat drive gear bolt lockstraps incorporated. {JE: what are these?!]


SB 168 - Jun 55: Oil - checking engine oil level: XK140 all cars: on cars with pressed steel sumps, oil level should not be above top mark on dipstick (when engine hot). So oil level to be checked when engine is hot.

Carburetor needles: change: For XK140s with C type heads, standard carbs, and disc type air cleaners - car needles recommended now WO2 (were SL). Change effected in

production from G3250 (and some earlier engines). This change effected whether 7:1 or 8:1 (again 9:1 not mentioned). Also mentioned spitting back problem referred to at SB 165 (change carb needles one alternative).

Overdrive - electrical circuit: XK140 from 800031/811382, 804121/814216, 807113/817426: relay incorporated into the circuit. The cable to the W1 terminal of the relay is taken from the "Aux Ign" fuse (no. 6 from front). The cable to the C1 terminal of relay taken from the "Aux" fuse (no.5 from front). New parts listed were relay C7472, manual switch harness (C9910 RHD, C9909 LHD).


SB 169 - Jun 55: Radiators: interchangeability: Listed the variations on XK140 radiators and mounting brackets.


Radiator Mounting brackets Fan Chassis numbers

C 10287 C 10288 C 10128, 15 1/2" diam FHC only 804001-019 814001-034


C 7523 C 8830 C 7516, 16" diam All 804020-141







C 9616 C 8830 C 7516, 16" diam All 804142 -

800037 -

807128 -

814241 -

811424 -

817460 -


C 9616 interchangeable with C 7523 if the water hose is changed and the tie rods are

replaced by radiator steady brackets C 9618 (2 off). It will be necessary to drill the wing valances for the attachment of the rear ends of the steady brackets. The first type of radiator was not interchangeable with the others. The 2 different fans were not interchangeable either.

Brakes: rear wheel cylinders: These were changed from 800025/811284, 804080/814153, 807080/817356. No details of changes. The new cylinders were C39377.

Batteries: acid level device: The acid level devices described in SB 100 were no longer

fitted. So the procedure became the standard top up until separators were just covered. Applied also to Mk VII.


SB 170 - Jun 55: Rear axles - shafts: XK120, C type, XK140: There was a table here

covering the Mk V, VII, 120, 140 models.

XK120 with Salisbury axles and all XK140: shafts had 19 splines and were 27-23/32" in

length, axle types were 2HA and 4HA. C type incidentally had 26-1/8" left hand axle, and 29-1/8" right hand axle (Sals 4HA, 19 splines) - i.e. unequal lengths.


SB 171 - Jun 55: Engine, gearbox removal: Detailed instructions provided here re XK140 (presumably reproduced later in Workshop Manual). Refers to XK140 fan cowling.


SB 172 - Sep 55B: Overdrive solenoid: setting procedure revised. Set out in detail.

Timing chain tensioner: Lower type changed. Commencing engine no. G4431, 4411 to 4420. Spring blade tensioner replaced with spring loaded Renold chain tensioner (C10332). New block number noted as C8610/1 (i.e. sole difference presumably the tensioner). The 2 types of tensioner were not interchangeable.


SB 173 - Sep 55: Front suspension: castor angle change: Altered from 2-1/2deg - 3 deg

positive to 1-1/2 deg - 2 deg positive. Chassis numbers listed for change. Recommended that it be implemented where the suspension was dismantled, or where there were complaints of "steering kick". Chassis nos.: 800052/811562, 804308/814532,



SB 174 - Dec 55: Cylinder heads: Modified form now used, with reduced depth of tapped holes for studs on the inlet face. The following were the new part nos.:

C6733/1 - standard head

C7707/1 - C type

C7896/1 - D type

superseding in each case the same number without the /1. The early, longer studs were of course not to be fitted to these modified heads. The difference in length was 3/16". It is interesting to note here that the studs for D type engines were referred to in this SB as being for the "XK.120"D" All engines".


SB 175 - Dec 55: Oil filter: Commencing engine no. G6233, new type oil filter fitted: head of the centre bolt was at the bottom of the filter canister and not at the top of the filter head as with previous types. Complete assembly Tecalemit FA 2708, C11524. Canister was 61874, filter head assembly 41034; other parts were listed in the SB.

Owner identification cards: "Owner's Identification Cards are now being included in literature envelopes of new cars despatched from the works. These cards are provided for the following reasons:-

1. To provide the owner with a card of the size easily contained in a wallet, to which he can readily refer for details of chassis, engine number, ignition and boot lock key numbers etc.,

2. To enable the owner to identify himself as the original owner of a particular car should he call upon a Jaguar Distributor or Dealer other than the supplier of the car, and to provide the Distributor or Dealer upon whom he might call for service during the guarantee period, with evidence of by whom the car was supplied and the date of the original delivery of the car.

Distributors and Dealers are, therefore, requested to ensure that the Owner's Identification Card is fully completed and signed by the owner prior to a new car being handed over to the customer."

Wheels (disc): Identification of the 5-1/2K road wheels by 2 depressions in the rim adjacent to the valve hole has now been dispensed with. The only identification is now by " 5 1/2 K" stamped in the well of the wheel rim.

Overdrive - throttle switch: Introduced, from 800062/811866, 804523/815252,

807319/818193. It was a throttle switch incorporated into the electrical operation of the overdrive, with 2 relays fitted and modifications to the wiring harness. Purpose was to prevent a change from OD to top gear when decelerating with a closed throttle (as the throttle switch overrides the manual switch until the throttle is opened for acceleration). The throttle switch was C5605, relay (x2) C7472, gearbox harness C11215, relay harness (RHD C11212, LHD: OTS, DHC, C11214 - LHD FHC), connector cable C11216. Adjustment was per the Mk VII model (see p 16 of Laycock de Normanville Overdrive Service Manual), some directions also given here in SB.

SB 176 - Dec 55: Torque converter - modified mounting: Commencing engine no. G6615 - modified the fitting of the TC to the crankshaft by the 6 mounting studs on the TC being replaced by tapped holes, with some other changes including that the starter pinion housing cutaway is increased to avoid any possibility of fouling the engine drive plate (which had been increased in diameter).

SB 179 -- Jan 56: Overdrive units: Table shows the interchangeability of parts between the OD units fitted to the XK140, Mk VII and 2.4 litre models. There was a change in the planetary carrier but both types were interchangeable and the part no. policy was indicated when it was stated: "As both types are fully interchangeable, no alteration has been made to the part number". Solenoid operating levers were C8766 for XK140 and later MkVII (2.4 L is different).


SB 182 - Mar 56: Mirror: Noted that the XK140 "driving mirror" was adjustable height by rotating the knurled sleeve anti-clockwise.


SB 183 - Mar 56: Rev counter cable: Modified cable (DHC - C11961 / FHC - C11963) fitted in place of DHC-C8274 FHC-C9154 commencing 807367/818385, 804640/815395. The difference was that the new type had a nylon insert at one end of the inner cable. (Note: information repeated at SB 185 for some reason).


SB 185 - Apr 56: Valve guides - exhaust (C type head): Modified valves and guides fitted from G6678S. The valves part no. was unchanged at C7708 and the guides were C8312. The valve stem was reduced in diameter under the valve head to form a scraping edge inside the guide. The new valve was now common to both standard and C type heads and would be fitted to all future production. See earlier Bulletin.

Oil: Esso recommendations: New range of Esso oils introduced; recommendations now

Esso Extra motor oil 20W/30 for summer/winter, and 40/50 for tropical. [query whether there was any change in the ID plates fitted to XK140s to reflect this change.

Paint colours: The following additional colours were now added to those in SB 114, 136, for XK140, Mk VII and 2.4 models (all were British Domolac brand, and the reference numbers for Quick Air Drying Enamel were:

British Racing Green Q 1076

Birch Grey Q 1079

Pearl Grey Q 1129

Pacific Blue Q 1132/1

Carmen Red Q 1190

Arbor Green Q 1191

Maroon Q 1135/1


SB 186 - Apr 56: Rear axle - larger drive gear bolts: bolts increased in size from 3/8" to 7/16". Chassis numbers: 800017/812311, 804676/815528, 807389/818488.

Suppressors - coil failure: Sometimes caused by suppressor in HT lead between coil and distributor in end of coil instead of in centre terminal post of distributor cap.


SB 192 - Jul 56: Tensioner: spares kit available for servicing Renold type tensioner.


SB 195 - Sep 56: Pre delivery cleaning - engine: "Engine parts liable to corrosion are

coated with Lanolin before cars leave the factory and it has been assumed that this would be cleaned off before the car was delivered to the customer. It would appear however that this has not always been carried out and we would request that Distributors and Dealers ensure that engines are cleaned down prior to delivery."

Fly off handbrake: Commencing 800072/812647, 804767/815755, 807441/818729 - new fly off handbrake fitted. Pull back and press button to set it. [No explanation of the difference between the old and new types.]


SB 196 - Sep 56: Gearbox identification: Set out details of prefixes and suffixes (without explaining them generally) for all models. Close ratio gearboxes had CR or MS suffixes. Ratios detailed.

Pre delivery cleaning - body: "To preserve the exterior finish, cars now being produced are treated with a protective wax coating. This protective coating must be removed when the car is being prepared for delivery to the customer or before the car is placed in your showrooms." The procedure for removal was to wash the car, and remove the wax with white spirit (petroleum distillate) or petrol applied with a mutton cloth or similar non-abrasive cloth. Alcohol was to be avoided.


SB 198 - Oct 56: Doors - material: Commencing 804781/815773, 807447/818796, doors for the FHC and DHC models were steel rather than aluminium alloy.


SB 199 - Oct 56: Speedo cables: Modified type of speedo cable with nylon insert at one

end of the inner cable fitted - part nos.: standard trans C8303, overdrive C11964, auto C

11965. Chassis numbers:

Standard trans: 800074/812707, 804781/815778, 807447/818801

Overdrive: 800072/812735, 804784/815830, - /818493

Auto: - / - , 804677/815532, 807387/818493.

Complete assemblies only (not inner/outers individually) were interchangeable.


SB 200 - Nov 56: Heads (Mk VIII): Described as B type, painted turquoise between the

valve covers, SD 1051 (complete assembly). Valve seat angle now 45deg (was 30 deg),

inlet valves 1-3/4", exhaust 1-5/8".


SB 200A - Jan 57: Mk VIII advance information (contd): Head part no. C 12500.


SB 201 - Nov 56: Gearbox: mainshaft assembly instructions: Set out here in detail.


SB 204 - Jan 57: Oil: multi grade; oil consumption: Greater oil consumption resulted from use of multigrade oils



SB 205 - Jan 57: Paint colours - additional: Following colours added to those in SB 114,

136 and 185, references for Quick Air Drying Enamel:

Imperial Maroon Q 1229

Claret Q 1230

Sherwood Green Q 1231

Cornish Grey Q 1236

Mist Grey Q 1235

Indigo Blue Q 1233

Cotswold Blue Q 1234

Hub puller: Service tool available from Churchills, Middlesex.


SB 206 - Jan 57: Petrol economy: Various recommendations to increase economy: replace spark plugs N8B with NA8; use multi grade oil (esp. to reduce use of choke); increase tyre pressures; ensure that thermostat and air cleaners are working properly. By fitting weak needles and limiting revs to 3000 rpm, considerable savings would be effected. Needles were SJ (std) LBA (weak) and for C type heads were W02 (std) and SL (weak).


SB 207 - Feb 57: Lubricants: Duckhams added: The recommended lubricants of Duckhams were listed here - new brand recommended. [Query: did the ID plates change hereafter?]


SB 210 - Feb 57: Head gasket: Future supplies (including 120, 140) would be the steel type gasket C7861 which superseded the Klingerite type C2250 and cupro-nickel gasket C3335.


SB 211 - Feb 57: Advance information re 3.4 litre model: B type head, .004/.006 clearances, various other items of basic information, including parts list. Engine nos. starting at KE1001.


SB 214 - May 57: Gearbox: JS suffix: For all models, a new type of gearbox "with shaved gears" was now in production - suffix JS. Ratios were top 1:1, 3rd 1.283, 2nd 1.86, 1st 3.378. There was a list of variations from standard gearboxes, including the front end cover, and it was noted that a smaller front oil seal was fitted.




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