| Description | Date | Identifier | |
| Investigation into a 25HP S.M. gearbox, focusing on the spigot bearing for production. | 11th Jan 1932 | Box 104 \ 4 scan0090 | |
| Production updates and improvements for the 25 HP Synchro Mesh Gearbox. | 18th Jan 1932 | Box 104 \ 4 scan0091 | |
| List of design changes for the 20/25HP Synchro-Mesh Gear Box on experimental chassis. | 20th Jan 1932 | Box 104 \ 4 scan0092 | |
| The manufacturing and finishing processes for vehicle gears, including burnishing, grinding, and potential design alternatives. | 20th Jan 1932 | Box 104 \ 4 scan0093 | |
| Standardisation sheet regarding the 25HP chassis synchro-mesh gearbox and its modifications. | 20th Jan 1932 | Box 104 \ 4 scan0094 | |
| The introduction of a burnishing process for the 20/25 HP Easy Change Gearbox 'U' Series. | 26th Jan 1932 | Box 104 \ 4 scan0095 | |
| Required modifications to the 25HP synchromesh gearbox concerning pinion length and reverse shaft bush clearance. | 27th Jan 1932 | Box 104 \ 4 scan0096 | |
| Experiments to cure overrun gear rattles on a 25HP car using a friction damper. | 15th Mar 1932 | Box 104 \ 4 scan0097 | |
| Confirming a modification to the 25 HP Synchromesh Gear Box regarding the number of plungers to be fitted. | 1st Feb 1932 | Box 104 \ 4 scan0098 | |
| Instruction regarding the installation of a new single bush in the reverse pinion for the 25 HP synchro mesh. | 10th Feb 1932 | Box 104 \ 4 scan0099 | |
| Test report on a new full length taper bush for the 25HP Synchromesh reverse gear. | 12th Feb 1932 | Box 104 \ 4 scan0100 | |
| Data sheet detailing gear ratios for a 20/25 HP Synchro Mesh Box with different axle configurations. | 1st Feb 1932 | Box 104 \ 4 scan0101 | |
| Cancelling a previous instruction on the plunger arrangement for the 25 HP Synchromesh. | 6th Feb 1932 | Box 104 \ 4 scan0102 | |
| Solution for gear rattles on the 25 HP model by adding a friction damper. | 24th Feb 1932 | Box 104 \ 4 scan0103 | |
| Future of gearboxes, considering synchro-mesh and helical gears. | 27th Feb 1932 | Box 104 \ 4 scan0104 | |
| Different schemes and considerations for a silent gearbox design. | 3rd Mar 1932 | Box 104 \ 4 scan0105 | |
| Schematic diagrams of a gearbox layout, gear engagement, and ratios. | 9th Mar 1932 | Box 104 \ 4 scan0106 | |
| On overcoming noisy engine gears and arranging production of new gears similar to helical gears. | 9th Mar 1932 | Box 104 \ 4 scan0107 | |
| Query regarding the synchro-mesh gearbox and silent third gear on the last 20 20/25 HP 'T' Series chassis. | 6th Apr 1932 | Box 104 \ 4 scan0108 | |
| Confirming the successful testing of silent third speed on production chassis fitted with synchro-mesh. | 9th Apr 1932 | Box 104 \ 4 scan0109 | |
| Standard cure for rattles and booms in the transmission. | 19th Apr 1932 | Box 104 \ 4 scan0110 | |
| Internal memorandum regarding the investigation and proposed solutions for transmission vibration in the 20/25 model. | 19th Apr 1932 | Box 104 \ 4 scan0111 | |
| Development of a full synchromesh gearbox to remain competitive against other manufacturers. | 19th Apr 1932 | Box 104 \ 4 scan0112 | |
| Proposal to modify the dynamometer test for the 20/25HP Synchro Mesh chassis by increasing engine r.p.m and removing the third gear run. | 20th Apr 1932 | Box 104 \ 4 scan0113 | |
| Difficulty of engaging first gear in the synchro-mesh gearbox. | 20th Apr 1932 | Box 104 \ 4 scan0114 | |
| Standardisation of a rear brake equalising shaft to suit a synchro mesh gearbox. | 8th Jan 1932 | Box 104 \ 4 scan0115 | |
| Standardisation sheet detailing the fitting of a new part to a specific chassis. | 19th Mar 1932 | Box 104 \ 4 scan0116 | |
| Transmission vibration issues, specifically 'Coronation Rattles', in the 20/25 and Silver Ghost models. | 21th Apr 1932 | Box 104 \ 4 scan0117 | |
| Troubles with a 20/25 HP Synchromesh Gearbox and questioning the extent of its original testing. | 28th Apr 1932 | Box 104 \ 4 scan0118 | |
| Decision not to proceed with a Synchromesh Gearbox on certain new models. | 28th Apr 1932 | Box 104 \ 4 scan0119 | |
| The history, testing, and known faults of the 20/25 HP synchro-mesh gearbox. | 29th Apr 1932 | Box 104 \ 4 scan0120 | |
| Gearbox faults and the lengthy development and testing timeline for new designs. | 29th Apr 1932 | Box 104 \ 4 scan0121 | |
| Telegram regarding issues with synchromesh, gearboxes, and servo mechanisms. | 2nd May 1932 | Box 104 \ 4 scan0122 | |
| Requesting a recommendation and a meeting to discuss a telegram regarding transmission vibration and a gearbox damper. | 2nd May 1932 | Box 104 \ 4 scan0123 | |
| Performance, testing, and production issues of the 20/25 HP Synchromesh Gearbox. | 2nd May 1932 | Box 104 \ 4 scan0124 | |
| The issue of the 3rd gear disengaging in the 25HP Synchromesh gearbox and the recommended solution. | 1st May 1932 | Box 104 \ 4 scan0125 | |
| Blueprint illustrating three positions of a 20/25 Synchromesh sliding piece and related gear engagement issues. | 4th May 1932 | Box 104 \ 4 scan0126 | |
| The 20/25 HP Synchro Mesh Gear Box. | 4th May 1932 | Box 104 \ 4 scan0127 | |
| Testing, faults, and modifications for the 20/25 HP Synchro Mesh Gear Box. | 3rd May 1932 | Box 104 \ 4 scan0128 | |
| Gearbox improvements, including synchromesh issues, reverse gear problems, and lengthening gearboxes for various models. | 4th May 1932 | Box 104 \ 4 scan0129 | |
| Telegram about the implementation of synchromesh and clutch brakes on gearboxes. | 6th May 1932 | Box 104 \ 4 scan0130 | |
| Instruction to add an air release hole to the synchromesh 3rd and 4th sliding piece. | 6th May 1932 | Box 104 \ 4 scan0131 | |
| Cause of transmission rattles, with tests related to crankshaft dampers and torsional periods. | 5th May 1932 | Box 104 \ 4 scan0132 | |
| Use of a clutch brake with a synchromesh gearbox on the 20/25 and Phantom II models. | 7th May 1932 | Box 104 \ 4 scan0133 | |
| Performance and development of the synchro-mesh gearbox, comparing the 25 HP and Phantom II models. | 7th May 1932 | Box 104 \ 4 scan0134 | |
| Issues and solutions for engaging gears from a standstill on a synchromesh gearbox, referencing car 19-EX. | 20th May 1932 | Box 104 \ 4 scan0135 | |
| Technical memo discussing transmission vibration issues, its potential causes, and proposed solutions. | 14th Apr 1932 | Box 104 \ 4 scan0136 | |
| Typed note discussing the undesirability of a proposed damper for various car models. | 5th May 1932 | Box 104 \ 4 scan0137 | |
| With diagrams discussing the design and mechanics of a reverse pinion and gear ratios for a gearbox. | 5th May 1932 | Box 104 \ 4 scan0138 | |
| Reverse pinions, jaw clutches, and a proposed design for a hub and sleeve assembly with a diagram. | 20th May 1932 | Box 104 \ 4 scan0139 | |
| Design modifications for the Phantom II - 20-HP Synchromesh to fix two known faults. | 27th May 1932 | Box 104 \ 4 scan0140 | |
| Design of the Bensport head and progress on the J.3. and Bensport gearboxes. | 1st May 1932 | Box 104 \ 4 scan0141 | |
| The testing of a reverse shaft for P.2 and 25-HP models and potential gearbox modifications. | 27th Jun 1932 | Box 104 \ 4 scan0142 | |
| Customer and test complaints for the New 25-HP Synchro Mesh Car. | 1st Jul 1932 | Box 104 \ 4 scan0143 | |
| Inquiry regarding the chassis or gearbox numbers fitted with new third motion shafts for the 20/25HP Synchro Mesh programme. | 1st Jul 1932 | Box 104 \ 4 scan0144 | |
| Listing specific 20/25 HP chassis and synchro-mesh gearboxes fitted with G.55561 third motion shafts. | 2nd Jul 1932 | Box 104 \ 4 scan0145 | |
| Standardisation of chassis parts for a Synchro Mesh Gearbox to the latest modifications. | 5th Jan 1932 | Box 104 \ 4 scan0146 | |
| The standardization of chassis parts, including the first chassis number, test date, and associated costs. | 19th Mar 1932 | Box 104 \ 4 scan0147 | |
| Analysis of transmission and engine vibrations, focusing on torsional crankshaft deflection and damping methods. | 5th May 1932 | Box 104 \ 4 scan0148 | |
| Technical note regarding engine and transmission vibration experienced on the 25HP model. | 24th May 1932 | Box 104 \ 4 scan0149 | |
| Cause of transmission rattle and proposing a rubber block drive as a potential solution. | 24th May 1932 | Box 104 \ 4 scan0150 | |
| Page 2 of a memo discussing a friction-damped spring coupling in the transmission, referencing the Silver Ghost model. | 30th May 1932 | Box 104 \ 4 scan0151 | |
| Gearboxes and the issue of creeping gears on splines. | 30th May 1932 | Box 104 \ 4 scan0152 | |
| Testing of synchronous mesh gears and the issue of gear creep under load. | 6th Apr 1932 | Box 104 \ 4 scan0153 | |
| Proposed 25-HP torsionally flexible joint and Hardy fabric coupling for the transmission. | 6th Apr 1932 | Box 104 \ 4 scan0154 | |
| Testing of a 25 HP Hardy fabric coupling behind the gearbox to eliminate 'Coronation Rattles'. | 9th Jun 1932 | Box 104 \ 4 scan0155 | |
| Proposed modification to the reverse gears for the 20/25 HP and Phantom II models. | 17th Jun 1932 | Box 104 \ 4 scan0156 | |
| Technical memorandum discussing design considerations for the P. 2 & 25HP reverse gear system. | 23th Jun 1932 | Box 104 \ 4 scan0157 | |
| Modifications to the gear control due to heaviness and high spring load on the reverse stop. | 25th Jun 1932 | Box 104 \ 4 scan0158 | |
| Discussion concerning the design and specifications for a gear lever reverse stop spring. | 19th Jul 1932 | Box 104 \ 4 scan0159 | |
| Successful testing of a new reverse gear design for the 20/25 HP model. | 12th Aug 1932 | Box 104 \ 4 scan0160 | |
| Modifications to the gear lever shaft for the 25HP model to prevent binding and reduce oil drag. | 13th Aug 1932 | Box 104 \ 4 scan0161 | |
| Inquiring about the travel of the reverse shaft on the 20/25 model to ascertain gear overlap. | 22th Aug 1932 | Box 104 \ 4 scan0162 | |
| The results of a test on a 20/25 reverse gear and subsequent alterations. | 26th Aug 1932 | Box 104 \ 4 scan0163 | |
| Tolerances for ball bearings on the 3rd motion shaft of the 25 HP & Peregrine gearbox. | 1st Sep 1932 | Box 104 \ 4 scan0164 | |
| Design of future gearboxes, focusing on achieving a silent helical second speed. | 7th Sep 1932 | Box 104 \ 4 scan0165 | |
| Gearbox noise issues and considering helical gears over synchromesh for the second gear. | 15th Sep 1932 | Box 104 \ 4 scan0166 | |
| Ball bearing fits and interference limits for 25 HP & Peregrine gearboxes. | 12th Sep 1932 | Box 104 \ 4 scan0167 | |
| Interference fit tolerances for an assembly involving bearings and gears on a threaded shaft. | 12th Sep 1932 | Box 104 \ 4 scan0168 | |
| Design disagreement regarding the silent 2nd gearbox and the placement of the freewheel and jaw clutch. | 1st Oct 1932 | Box 104 \ 4 scan0169 | |
| Design of the helical second gear for the 25HP gearbox. | 6th Oct 1932 | Box 104 \ 4 scan0170 | |
| Customer complaints of 'back lash' noise in Synchro Mesh Gear Boxes for the 20/25HP & Phantom II models. | 3rd Nov 1932 | Box 104 \ 4 scan0171 | |
| Adjusting gearbox clearances for a J.2 model to resolve transmission noise complaints. | 17th Nov 1932 | Box 104 \ 4 scan0172 | |
| Gearbox options, comparing synchro-mesh, silent second speed, and the Wilson gearbox, with a recommendation to adopt a silent second speed. | 22th Nov 1932 | Box 104 \ 4 scan0173 | |
| Gearbox requirements, specifically the need for a synchro-mesh second speed and consideration of the epicyclic gear. | 22th Nov 1932 | Box 104 \ 4 scan0174 | |
| Introducing a silent helical second gear and a modified reverse gear into the standard gearbox for all cars. | 28th Nov 1932 | Box 104 \ 4 scan0175 | |
| Schedule N.Sch.3633 for a helical second speed gear for the 20/25 J.II and J.III models. | 9th Jan 1933 | Box 104 \ 4 scan0176 | |
| Standardisation report for a chassis reverse gear to overcome difficulty engaging first gear. | 6th Sep 1932 | Box 104 \ 4 scan0177 | |
| Standardisation form for a Sump Case, detailing the origin of the change, test results, costs, and implementation schedule. | 25th Sep 1932 | Box 104 \ 4 scan0178 | |
| Transmission slack in compound epicyclic gears and potential design solutions. | 28th Jan 1933 | Box 104 \ 4 scan0179 | |
| Epicyclic gearing, comparing transmission slack and noise in Lanchester and Armstrong Siddeley cars. | 3rd Feb 1933 | Box 104 \ 4 scan0180 | |
| Standardisation of a modified 3rd motion shaft for the 25HP synchromesh gearbox to prevent 3rd gear disengagement on overrun. | 10th May 1932 | Box 104 \ 4 scan0181 | |
| Implementation of a new part onto a chassis, including associated costs. | 25th Jan 1933 | Box 104 \ 4 scan0182 | |
| Seizures of 3rd speed wheel bearings and potential lubrication improvements. | 25th Jan 1933 | Box 104 \ 4 scan0183 | |
| Experiments conducted to resolve gearbox over-run rattles using a slipper flywheel on a specific car. | 4th Feb 1933 | Box 104 \ 4 scan0184 | |
| Confirming a request to build up a new change speed mechanism for the 20/25 gearbox. | 8th Mar 1933 | Box 104 \ 4 scan0185 | |
| Results of testing helical second speed gears on Peregrine, 20/25, and 40/50 chassis. | 25th Mar 1933 | Box 104 \ 4 scan0186 | |
| Request to test the volumetric efficiency of a gear type pump for gearbox control. | 27th Mar 1933 | Box 104 \ 4 scan0187 | |
| Figures taken from a badly worn gear pump tested with Castrol XL oil at 70°C. | 5th Apr 1933 | Box 104 \ 4 scan0188 | |
| Gearbox control tests on a 20/25 HP oil pump using Castrol XL oil at 70°C. | 3rd Apr 1933 | Box 104 \ 4 scan0189 | |
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