| Description | Date | Identifier | |
| Advantage of changing to a new 3.5 to 1 back axle ratio and making it standard. | 16th Feb 1920 | Box 49 \ 1 Scan146 | |
| Advantages and standardisation of a new 3.5 to 1 back axle ratio. | 16th Feb 1920 | Box 49 \ 1 Scan147 | |
| New standard back axle ratio of 3.5 to 1 using Gleason gears. | 16th Feb 1920 | Box 49 \ 1 Scan148 | |
| Adoption of a new rear axle with a lower ratio of 3.5 to 1. | 24th Feb 1920 | Box 49 \ 1 Scan149 | |
| Adoption of a new axle with a lower gear ratio of 3.5 to 1. | 2nd Feb 1920 | Box 49 \ 1 Scan150 | |
| Greater reduction ratio in the rear axle bevels and the production of experimental gears. | 25th Feb 1920 | Box 49 \ 1 Scan151 | |
| Production of experimental gears for a greater reduction ratio in the rear axle. | 2nd Feb 1920 | Box 49 \ 1 Scan152 | |
| Decision on the use of Gleason Bevel Wheels and a referenced note that has not been received. | 25th Feb 1920 | Box 49 \ 1 Scan153 | |
| Use of CHNS material for Gleason Bevel Wheels to overcome manufacturing difficulties. | 26th Feb 1920 | Box 49 \ 1 Scan154 | |
| List of specifications for a trials car intended for the American Company. | 4th Mar 1920 | Box 49 \ 1 Scan155 | |
| Potential non-standard additions and improvements for a trials car for the American company. | 4th Mar 1920 | Box 49 \ 1 Scan156 | |
| Adoption of a new gear ratio for low geared axles. | 15th Mar 1920 | Box 49 \ 1 Scan157 | |
| Characteristic 'jaggering' effect when braking vigorously over a pothole and potential solutions involving the clutch. | 9th Mar 1920 | Box 49 \ 1 Scan158 | |
| 'jaggering' issues caused by different types of axle control and braking. | 9th Mar 1920 | Box 49 \ 1 Scan159 | |
| Cover memo from CJ to Bn regarding 3X Springs and an enclosed memo from de Salamanca. | 3rd Mar 1920 | Box 49 \ 1 Scan160 | |
| Photographs from a road test concerning braking, wheel bumping, and skidding at 55 MPH. | 6th Aug 1919 | Box 49 \ 1 Scan161 | |
| Road test data recording bump measurements at speeds of 50 and 55 MPH. | 18th Mar 1920 | Box 49 \ 1 Scan162 | |
| Adoption of Gleason back axle bevels across different 40/50 car series. | 18th Mar 1920 | Box 49 \ 1 Scan163 | |
| Covering memorandum from CJ regarding a chassis memo from Mr. Royce. | 18th Mar 1920 | Box 49 \ 1 Scan164 | |
| Clarifying the company's philosophy on chassis design, distinguishing between luxury cars and racing machines. | 16th Mar 1920 | Box 49 \ 1 Scan165 | |
| Adoption of Gleason back axle bevels across different car models. | 18th Mar 1920 | Box 49 \ 1 Scan166 | |
| Standardisation of a rear axle casing in 3½% N.S. in lieu of M.S. for increased reliability. | 23th Mar 1920 | Box 49 \ 1 Scan167 | |
| Fitting of an experimental low geared axle to chassis 7-AE for practical trials. | 3rd Mar 1920 | Box 49 \ 1 Scan168 | |
| Comparative analysis of Packard and R-R rear axle weights and bevel gear specifications. | 24th Mar 1920 | Box 49 \ 1 Scan169 | |
| Rear axle period vibrations and potential cures for experimental cars. | 29th Mar 1920 | Box 49 \ 1 Scan170 | |
| The production progress of experimental bevel gears with a 15/52 teeth ratio for the rear axle. | 12th Apr 1920 | Box 49 \ 1 Scan171 | |
| Follow-up request for information regarding axle period vibrations. | 13th Apr 1920 | Box 49 \ 1 Scan172 | |
| Confirming the delivery of 6 pairs of 15 x 52 Spiral Bevel Gears to the Experimental Department. | 29th Apr 1920 | Box 49 \ 1 Scan173 | |
| Recurring axle tube breakage on chassis 1717 and an inquiry about preventative measures. | 29th Apr 1920 | Box 49 \ 1 Scan174 | |
| Investigation into a broken rear axle tube from chassis 1717. | 4th May 1920 | Box 49 \ 1 Scan175 | |
| Requesting a test on bolting and sweating brake brackets to rear axle tubes as an alternative to brazing. | 8th May 1920 | Box 49 \ 1 Scan176 | |
| Requesting a test to attach brake brackets to rear axle tubes by bolting and sweating, instead of brazing. | 8th May 1920 | Box 49 \ 1 Scan177 | |
| Inspection report and discussion on 20 HP chassis parts, including axles, bearings, and gearbox. | 18th May 1920 | Box 49 \ 1 Scan178 | |
| Requesting an order for experimental tests on one pair of axle tubes with fitted brake brackets. | 17th May 1920 | Box 49 \ 1 Scan179 | |
| Design considerations and requested modifications for various car components. | 18th May 1920 | Box 49 \ 1 Scan180 | |
| List of new parts being fitted to the 6.EX Car following a delay at the works. | 28th May 1920 | Box 49 \ 1 Scan181 | |
| Speed and acceleration tests at Brooklands comparing a standard axle with a new low-geared axle on a 49-GB car. | 15th Jun 1920 | Box 49 \ 1 Scan182 | |
| Performance test results table for acceleration, flying start, and lap speeds under various car configurations. | 19th Jul 1927 | Box 49 \ 1 Scan183 | |
| Standardisation of chassis parts, changing the lower gear back axle ratio from 16 x 52 to 15 x 52. | 20th Aug 1920 | Box 49 \ 1 Scan184 | |
| Comparing 14-tooth and 15-tooth axles regarding performance, engine wear, and petrol consumption for tests on 40/50 cars at Brooklands track. | 1st Jul 1922 | Box 49 \ 1 Scan185 | |
| Proposing a more realistic petrol consumption test for 40/50 cars, simulating various driving conditions. | 10th Jul 1922 | Box 49 \ 1 Scan186 | |
| Inward thrust on the back axle bevel gear and proposing two new schemes using ball thrust bearings. | 18th Jun 1920 | Box 49 \ 1 Scan187 | |
| Inward thrust on the back axle bevel gear, proposing two schemes to use a ball thrust bearing instead of a plain thrust washer. | 18th Jun 1920 | Box 49 \ 1 Scan188 | |
| Back axle bevel gear and proposing the use of ball thrust bearings to manage inward thrust. | 18th Jun 1920 | Box 49 \ 1 Scan189 | |
| List of experimental parts fitted to chassis 6.EX. | 22th Jun 1920 | Box 49 \ 1 Scan190 | |
| Requesting the manufacture of parts for an experiment on the 40/50 HP chassis rear axle. | 23th Jun 1920 | Box 49 \ 1 Scan191 | |
| Re-tests on car 49-GB at Brooklands, comparing the advantages of lower versus higher axle gears for different body types. | 25th Jun 1920 | Box 49 \ 1 Scan192 | |
| Extract detailing a list of experimental parts fitted to the 6.EX Car. | 28th Jun 1920 | Box 49 \ 1 Scan193 | |
| Calculating car speeds based on different axle ratios and tyre sizes. | 30th Jun 1920 | Box 49 \ 1 Scan194 | |
| Comparing car speeds with various axle ratios and tyre combinations. | 30th Jun 1920 | Box 49 \ 1 Scan195 | |
| From Mr. Royce discussing alterations to the back axle bevel gear for the 40/50 HP chassis. | 30th Jun 1920 | Box 49 \ 1 Scan196 | |
| High and low geared axles and performance with different tires. | 1st Jul 1920 | Box 49 \ 1 Scan197 | |
| Design considerations and feedback on various vehicle components including the back axle, springs, and body. | 17th Jul 1920 | Box 49 \ 1 Scan198 | |
| Dispatch of two blueprints for the method of fixing brackets to axle tubes on a 40/50 HP Chassis. | 20th Jul 1920 | Box 49 \ 1 Scan199 | |
| Fitting of a low-geared axle and a Smith Dynamo to test vehicles before standardisation. | 22th Jul 1920 | Box 49 \ 1 Scan200 | |
| Letter from Gleason Works confirming a gear shipment schedule and discussing production delays. | 22th Jul 1920 | Box 49 \ 1 Scan201 | |
| Letter from Rolls-Royce of America regarding production delays of 500 sets of bevel gears from Gleason Works. | 22th Jul 1920 | Box 49 \ 1 Scan202 | |
| Letter to Claude Johnson regarding an order for 500 sets of bevel gears from Gleason Works. | 24th Jul 1920 | Box 49 \ 1 Scan203 | |
| Blueprints for a double thrust race for the standard back axle, to accommodate Gleason gears on the 40/50 Chassis. | 31th Jul 1920 | Box 49 \ 1 Scan204 | |
| Bevel gears at the Gleason Works in Rochester, NY. | 5th Sep 1920 | Box 49 \ 1 Scan205 | |
| Testing and ordering of Gleason Bevel Gears from R.R. of A. Inc. | 6th Aug 1920 | Box 49 \ 1 Scan206 | |
| Suggesting new standardisations for axle gear ratios and Ferodo bonnet beading be implemented in American cars to resolve complaints. | 1st Aug 1920 | Box 49 \ 1 Scan207 | |
| Clarifying the testing status of Gleason Bevel Gears, stating that six have been tested and 500 more ordered. | 9th Sep 1920 | Box 49 \ 1 Scan208 | |
| Cover letter forwarding correspondence regarding Bevel Gears at Gleason Works, Rochester, N.Y. | 10th Aug 1920 | Box 49 \ 1 Scan209 | |
| Letter discussing the requirement to test Gleason bevel gears and pinions before completing an order for Rolls-Royce of America Inc. | 12th Aug 1920 | Box 49 \ 1 Scan210 | |
| Distributing standardisation sheets for experiments on rear springs, a luggage grid bracket, and a lower gear back axle. | 20th Aug 1920 | Box 49 \ 1 Scan211 | |
| Standardization of a low geared back axle, including test results and recommendations for production. | 20th Aug 1920 | Box 49 \ 1 Scan212 | |
| Knock in the transmission and a proposed solution of making the driving shafts more elastic. | 30th Aug 1920 | Box 49 \ 1 Scan213 | |
| Technical memorandum discussing modifications to address axle 'dithering' and clutch take-up issues. | 30th Aug 1920 | Box 49 \ 1 Scan214 | |
| For the review of standardization sheets for three vehicle components. | 2nd Sep 1920 | Box 49 \ 1 Scan215 | |
| To Mr. Clark detailing the receipt of various parts from suppliers into stores. | 9th Sep 1920 | Box 49 \ 1 Scan216 | |
| Authorising the production of 100 pairs of high reduction bevel gears with a 15-52 ratio. | 20th Sep 1940 | Box 49 \ 1 Scan217 | |
| Comparison report on the performance and fuel consumption of a lower ratio back axle in car 1.EX versus 6.EX. | 20th Aug 1920 | Box 49 \ 1 Scan218 | |
| New models for the Buzzard and Vulture engines, which are to be submitted to Mr. Royce for approval. | 2nd Oct 1920 | Box 49 \ 1 Scan219 | |
| Back axle ratios for covered cars, including specific weight-to-ratio recommendations. | 5th Oct 1920 | Box 49 \ 1 Scan220 | |
| Suitability of a three or four-speed gearbox for heavy luxury cars and their ability to handle steep grades. | 12th Oct 1920 | Box 49 \ 1 Scan221 | |
| Recommending increased back axle gear ratios for heavier cars, with specific ratios proposed based on vehicle weight. | 12th Oct 1920 | Box 49 \ 1 Scan222 | |
| Gear ratios, weight saving, and the preference for a three-speed over a four-speed gearbox for a new chassis design. | 12th Oct 1920 | Box 49 \ 1 Scan223 | |
| Internal memorandum arguing for a three-speed gearbox over a four-speed due to design complexity and overall vehicle perfection. | 12th Oct 1920 | Box 49 \ 1 Scan224 | |
| The merits of three-speed versus four-speed semi-epicyclic gear arrangements. | 12th Oct 1920 | Box 49 \ 1 Scan225 | |
| Suitability of a three or four-speed gearbox for heavy cars. | 12th Oct 1920 | Box 49 \ 1 Scan226 | |
| Recommendation for varying back axle gear ratios in proportion to car weight to improve performance. | 12th Oct 1920 | Box 49 \ 1 Scan227 | |
| Proposed back axle ratios and the advantages of a three-speed gearbox for a new chassis design. | 12th Oct 1920 | Box 49 \ 1 Scan228 | |
| Argument against a four-speed gearbox, advocating for a superior three-speed mechanism and a more perfect engine. | 12th Oct 1920 | Box 49 \ 1 Scan229 | |
| The merits of a four-speed semi-epicyclic gearbox arrangement compared to a three-speed. | 12th Oct 1920 | Box 49 \ 1 Scan230 | |
| Advantages of a lowered geared axle for future models, particularly for export. | 27th Oct 1920 | Box 49 \ 1 Scan231 | |
| Letter from Rolls-Royce of America Inc. to London regarding the design of the thrust bearing for the bevel pinion. | 19th Oct 1920 | Box 49 \ 1 Scan232 | |
| Letter from Rolls-Royce of America querying the design choice for the bevel pinion thrust bearing. | 19th Oct 1920 | Box 49 \ 1 Scan233 | |
| Cover memo forwarding a letter from America concerning a thrust bearing for a bevel pinion. | 3rd Nov 1920 | Box 49 \ 1 Scan234 | |
| Experimental car being prepared for winter testing in the U.S.A. | 4th Nov 1920 | Box 49 \ 1 Scan235 | |
| Provision of a double ball bearing thrust behind the bevel pinion on the propeller shaft. | 4th Nov 1920 | Box 49 \ 1 Scan236 | |
| Necessity and implementation of a double thrust bearing for the rear axle pinion. | 1st Nov 1920 | Box 49 \ 1 Scan237 | |
| Returning signed standardisation sheets for steering pivot pins and a rear axle pinion bearing. | 11th Nov 1920 | Box 49 \ 1 Scan238 | |
| American visit discussing Gleason gears, bodywork issues, and general production points. | 11th Nov 1920 | Box 49 \ 1 Scan239 | |
| Interview with a Gleason gear expert, issues with body work, and general manufacturing points. | 11th Nov 1920 | Box 49 \ 1 Scan240 | |
| The specifications for a small chassis, including the gearbox, back axle, brakes and suspension. | 17th Nov 1920 | Box 49 \ 1 Scan241 | |
| Extract detailing proposals for a new small chassis, including engine and construction variations. | 17th Nov 1920 | Box 49 \ 1 Scan242 | |
| Revised 20 HP chassis, detailing the brake gear, underslung springs, and requesting calculations for the rear road springs. | 27th Nov 1920 | Box 49 \ 1 Scan243 | |
| Continued note regarding ordering side channels for a frame. | 27th Nov 1920 | Box 49 \ 1 Scan244 | |
| New lower gear ratio scheme (3.71) for the 40/50 back axle and proposing tests on three sets. | 27th Nov 1920 | Box 49 \ 1 Scan245 | |
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