| Description | Date | Identifier | |
| Instructions regarding modifications to the gearbox and starter on engine, including electrical system changes. | 1st Mar 1926 | Box 15 \ 4 Scan003 | |
| Progress report on detachable dash connections, lighter clutch, propeller shaft joints, and gearbox design. | 1st Mar 1927 | Box 15 \ 4 Scan004 | |
| Failure of a locking device on the 12-EX Phantom engine coupling and a recommended solution. | 1st Mar 1927 | Box 15 \ 4 Scan005 | |
| Design and application of a universal joint for project EAC.10. | 1st Jan 1928 | Box 15 \ 4 Scan006 | |
| Technical memorandum discussing the design and material choices for a propeller shaft universal joint. | 25th Jan 1928 | Box 15 \ 4 Scan007 | |
| New 6-inch universal joint and propeller shaft, awaiting further comments before detailing. | 15th Feb 1928 | Box 15 \ 4 Scan008 | |
| Alternative design proposal for a 6' Universal Joint. | 18th Feb 1928 | Box 15 \ 4 Scan009 | |
| Design memo discussing preferences for the 'SS' propeller shaft. | 5th Mar 1928 | Box 15 \ 4 Scan010 | |
| Design options for an 'SS' propeller shaft. | 5th Mar 1928 | Box 15 \ 4 Scan011 | |
| Design options and drawings for the 'SS' propeller shaft. | 10th Mar 1928 | Box 15 \ 4 Scan012 | |
| Modification to the centralised chassis lubrication system for the universal joint and torque sphere. | 17th May 1928 | Box 15 \ 4 Scan013 | |
| Suggestion to improve crankshaft lubrication for a lightened clutch and universal joint by using a stainless steel plug or cadmium plating. | 10th Oct 1928 | Box 15 \ 4 Scan014 | |
| Stainless steel plug and concerns over the lubrication system for a clutch joint. | 17th Oct 1928 | Box 15 \ 4 Scan015 | |
| Fitting of a stainless steel plug to a lightened clutch and flywheel for vehicle 12-EX. | 17th Oct 1928 | Box 15 \ 4 Scan016 | |
| Oil leak from the steel sphere on 40/50 models and a recommended diagnostic test. | 28th Nov 1928 | Box 15 \ 4 Scan017 | |
| The oil retention requirements and production testing for 'SS' model propeller shaft joints. | 6th Dec 1928 | Box 15 \ 4 Scan018 | |
| Flexible coupling on the SS chassis due to increased engine power. | 27th Jan 1929 | Box 15 \ 4 Scan019 | |
| Replacement of fabric couplings with serrated ones to improve design and save weight. | 12th Feb 1929 | Box 15 \ 4 Scan020 | |
| Flexibility of trunnion bearings for SS Universal Joints compared to other models. | 2nd Feb 1929 | Box 15 \ 4 Scan021 | |
| Proposed modification to a serrated universal joint and SS. clutch shaft, focusing on lubrication. | 19th Feb 1929 | Box 15 \ 4 Scan022 | |
| Telegram reporting that experimental universal joints are leaking badly during a rig test. | 8th May 1918 | Box 15 \ 4 Scan023 | |
| Arranging for the immediate testing of a propeller shaft from the 23-EX car on a testing rig. | 1st Mar 1929 | Box 15 \ 4 Scan024 | |
| Testing of propeller shaft joints to prevent oil leakage, comparing washer materials and noting the need for a jointing solution. | 4th Apr 1929 | Box 15 \ 4 Scan025 | |
| Recommendation to add an oil groove to propeller shaft bearing trunnions to improve wear. | 14th May 1929 | Box 15 \ 4 Scan026 | |
| Blueprint detailing modifications to a trunnion block, including an enlarged view of a hole edge. | 17th Apr 1929 | Box 15 \ 4 Scan027 | |
| Modifications to universal joint filler plugs and washers to prevent oil leaks. | 17th Apr 1929 | Box 15 \ 4 Scan028 | |
| Request to test the propeller shaft for the 21-EX car for oil retention before being fitted. | 19th Apr 1929 | Box 15 \ 4 Scan029 | |
| Tests and solutions for oil leakage in propeller shaft universal joints. | 1st Apr 1929 | Box 15 \ 4 Scan030 | |
| Continued memorandum on the lubrication of Mechanics Joints, with an attached blueprint detail. | 1st May 1923 | Box 15 \ 4 Scan031 | |
| Recommending reverting to a fabric coupling for '33' cars due to faults, and proceeding slowly with improvements to the S.S. exhaust system. | 1st May 1923 | Box 15 \ 4 Scan032 | |
| Confirming the decision to use a fabric engine coupling instead of an all-metal one for the S.S. Chassis. | 8th May 1929 | Box 15 \ 4 Scan033 | |
| Urgent request to produce a SS. Fabric Coupling to test a method of securing plates on a test rig. | 31th May 1929 | Box 15 \ 4 Scan034 | |
| Letter from the American branch to the UK branch inquiring about the removal of the fabric engine coupling from S.S. layouts. | 12th Jun 1929 | Box 15 \ 4 Scan035 | |
| Request to make 4 sets of 'SS' Fabric Couplings with shorter rivets based on an attached scheme. | 8th Jun 1929 | Box 15 \ 4 Scan036 | |
| Engine suspension rubbers, rear support vibrations, and a reversion to fabric engine couplings. | 21th Jun 1929 | Box 15 \ 4 Scan037 | |
| Improving the lifespan of fabric couplings by comparing riveting and screwed thimble methods. | 21th Jun 1929 | Box 15 \ 4 Scan038 | |
| Answering seven questions about the characteristics and effects of body subframes. | 21th Jun 1929 | Box 15 \ 4 Scan039 | |
| Continued document detailing numbered points on construction and mentioning an attached report on subframe difficulties. | 1st Feb 1929 | Box 15 \ 4 Scan040 | |
| Proposed modifications to the subframes for two chassis types. | 1st Feb 1929 | Box 15 \ 4 Scan041 | |
| Difficulties of fitting S.S. bodies to chassis and proposing a building rig for coachbuilders. | 17th Apr 1929 | Box 15 \ 4 Scan042 | |
| Supply of subframe brackets and chassis templates to coachbuilders. | 29th Apr 1929 | Box 15 \ 4 Scan043 | |
| Subframe and chassis interchangeability for S.S. bodies and guidance for coachbuilders. | 29th Apr 1929 | Box 15 \ 4 Scan044 | |
| The challenges of coachbuilding for a new model, including issues with secrecy and experimental bodies. | 1st May 1929 | Box 15 \ 4 Scan045 | |
| Difficulties and solutions for mounting bodies on S.S. model subframes. | 1st May 1929 | Box 15 \ 4 Scan046 | |
| Dyno and road testing of axles and propeller shafts for chassis 23-EX. | 21th Jun 1929 | Box 15 \ 4 Scan047 | |
| Test data table for propeller shaft periods against buffer-axle clearances at various throttle settings. | 16th May 1929 | Box 15 \ 4 Scan048 | |
| Notice regarding the use of a standard fabric engine coupling for the J.2 series chassis. | 16th May 1929 | Box 15 \ 4 Scan049 | |
| Test results of different manufacturing schemes for fabric couplings to improve their lifespan. | 4th Jul 1929 | Box 15 \ 4 Scan050 | |
| Comparison of coupling life using spigoted bolts versus unspigoted bolts, noting application differences between Phantom and S.S. models. | 4th Jul 1929 | Box 15 \ 4 Scan051 | |
| Cross-sectional drawing of a bolted assembly. | 5th Jul 1929 | Box 15 \ 4 Scan052 | |
| Rectangular purple stamp from the Print Room. | 5th Jul 1929 | Box 15 \ 4 Scan053 | |
| Blueprint detailing different test designs for a fabric coupling. | 21th Jul 1929 | Box 15 \ 4 Scan054 | |
| Heavily faded document with an ink stamp in the bottom right corner. | 10th Jul 1929 | Box 15 \ 4 Scan055 | |
| Query on incorporating modifications for fabric couplings and an exhaust cut-out valve into the first batch of S.S. chassis. | 15th Jul 1929 | Box 15 \ 4 Scan056 | |
| Failure of fabric couplings on cars used for high-speed continental work. | 11th Sep 1929 | Box 15 \ 4 Scan057 | |
| The failure modes of fabric couplings and the need for improvements. | 24th Sep 1929 | Box 15 \ 4 Scan058 | |
| Extract concerning a propeller shaft fouling issue on the S.S. Chassis. | 1st Aug 1929 | Box 15 \ 4 Scan059 | |
| Query regarding the recommended maintenance interval for propeller shaft universal joints on 20HP and SS chassis. | 13th Aug 1929 | Box 15 \ 4 Scan060 | |
| Recommendation for propeller shaft lubrication intervals for 20 HP and 40/50 HP chassis. | 14th Aug 1929 | Box 15 \ 4 Scan061 | |
| Potential issues and replacement policy for Phantom II propeller shaft universal joints. | 23th Oct 1929 | Box 15 \ 4 Scan062 | |
| Risk of propeller shaft failure and safety features on the 20 HP, Phantom II, and Silver Ghost models. | 24th Jan 1930 | Box 15 \ 4 Scan063 | |
| Report on oil leakage from the sliding joint of the main universal for the Phantom II and 20/25 HP models. | 26th May 1930 | Box 15 \ 4 Scan064 | |
| The failure of fabric couplings on the Phantom II and the introduction of a new rivetted design. | 23th May 1930 | Box 15 \ 4 Scan065 | |
| Potential issue with the Hardy Coupling fitted to 'Phantom II' cars. | 27th May 1930 | Box 15 \ 4 Scan066 | |
| On issues with the fabric coupling on early Phantom II chassis and the recommended modification to prevent crankcase damage. | 28th May 1930 | Box 15 \ 4 Scan067 | |
| Trouble with fabric couplings and bolt fractures on Phantom II cars. | 2nd Jun 1930 | Box 15 \ 4 Scan068 | |
| Standardisation of chassis parts, replacing screws and ferrules with rivetted plates on fabric couplings. | 22th May 1930 | Box 15 \ 4 Scan069 | |
| Use of cantilever pins versus rivets on fabric couplings. | 26th Aug 1930 | Box 15 \ 4 Scan070 | |
| Failure rates of different engine coupling types on the Phantom II. | 25th Aug 1930 | Box 15 \ 4 Scan071 | |
| The failure of a fabric engine coupling on chassis 18-XJ and a discussion of its design. | 2nd Oct 1930 | Box 15 \ 4 Scan072 | |
| Emergency modification to a coupling using three discs. | 14th Oct 1930 | Box 15 \ 4 Scan073 | |
| Request to prepare standard, Hardy type A, and bulge couplings for a fabric coupling joggling rig. | 14th Oct 1930 | Box 15 \ 4 Scan074 | |
| Recommendation to circulate a Depot Sheet about fitting the latest rivetted engine couplings on Phantom I & II models. | 18th Dec 1930 | Box 15 \ 4 Scan075 | |
| Failures, benefits, and proposed improvements for fabric couplings on the Phantom II model. | 20th Apr 1931 | Box 15 \ 4 Scan076 | |
| Need to increase propeller shaft diameter to prevent whirling at higher RPMs. | 4th Nov 1931 | Box 15 \ 4 Scan077 | |
| Letter from Cadillac Motor Car Company providing information on propeller shaft assemblies for high-speed boats. | 21th Oct 1931 | Box 15 \ 4 Scan078 | |
| Specifications for car shafts, including balance, RPM, and thickness. | 19th Oct 1931 | Box 15 \ 4 Scan079 | |
| Letter discussing drive shaft tube critical speed calculations and specifications. | 19th Oct 1931 | Box 15 \ 4 Scan080 | |
| Standardisation of a 2.750' diameter propeller shaft to prevent whirling. | 12th Aug 1932 | Box 15 \ 4 Scan081 | |
| Standardisation form for a chassis part, detailing its implementation, schedule and cost. | 15th Sep 1928 | Box 15 \ 4 Scan082 | |
| Reliability of the Synchromesh Fabric Coupling Bolts on the Phantom II. | 19th Aug 1932 | Box 15 \ 4 Scan083 | |
| Failure of Hardy fabric couplings on Phantom II cars and suggesting a design modification to reduce replacement costs. | 20th Sep 1932 | Box 15 \ 4 Scan084 | |
| Alternate proposals for a torsionally flexible coupling. | 27th Oct 1932 | Box 15 \ 4 Scan085 | |
| Standardisation of an engine coupling to address complaints of fabric disintegration. | 9th Feb 1933 | Box 15 \ 4 Scan086 | |
| Introduction of a new part for a 'P' Series chassis. | 2nd Sep 1933 | Box 15 \ 4 Scan087 | |
| Request to develop a needle bearing propeller shaft for the Phantom II model based on a successful test. | 20th Oct 1933 | Box 15 \ 4 Scan088 | |
| Request to test and modify the rear universal joint on experimental car 22-EX to measure axle twist and spring deflection. | 19th Apr 1934 | Box 15 \ 4 Scan089 | |
| Modifications to cure fouling on Phantom propeller shafts. | 9th May 1934 | Box 15 \ 4 Scan090 | |
| Recommendation for Vacuum Motor Grease No. 2 for needle type bearings on 20/25 & 40/50 HP chassis universal joints. | 30th May 1934 | Box 15 \ 4 Scan091 | |
| Standardisation of a propeller shaft with needle bearings in mechanics joints. | 10th May 1934 | Box 15 \ 4 Scan092 | |
| Estimated cost for extra jigs, tools, and equipment for a modification instructed for the 'S.2' series. | 25th May 1934 | Box 15 \ 4 Scan093 | |
| Investigation report into a universal joint failure on a PH.II Chassis after a customer complaint of noise in the transmission. | 20th Jul 1934 | Box 15 \ 4 Scan094 | |
| Depot sheet concerning oil loss from Phantom II rear universal joints and the required modification. | 24th Jul 1934 | Box 15 \ 4 Scan095 | |
| Modifications and leaking issues with Ph.II rear universal joints. | 24th Jul 1934 | Box 15 \ 4 Scan096 | |
| Standardisation of a new, shorter propeller shaft to suit a new gearbox. | 16th Oct 1934 | Box 15 \ 4 Scan097 | |
| Cost estimate and production note regarding jigs and tools for the 'D' series chassis. | 20th Oct 1934 | Box 15 \ 4 Scan098 | |
| Instructions for modifications to the gearbox and the starter on engine. | 1st Mar 1926 | Box 15 \ 5 Scan001 | |
| Progress report on a detachable connection, lighter clutch, propeller shaft, and gearbox design. | 29th Mar 1926 | Box 15 \ 5 Scan002 | |
| With a sketch proposing the use of electric welding for the EAC.7 gearbox striking forks to simplify the manufacturing process. | 29th Mar 1926 | Box 15 \ 5 Scan003 | |
| Inquiry about experimental results for straight ground teeth in constant mesh gearboxes for the EAC. 7 design. | 29th Mar 1926 | Box 15 \ 5 Scan004 | |
| | | | |