| Description | Date | Identifier | |
| Troubleshooting noise from a dynamo ball bearing and harshness in the clutch, with a suggested design change. | 22th Sep 1919 | Box 74 \ 2 scan0260 | |
| Harsh operation of a fabric clutch and suggesting potential improvements. | 23th Sep 1919 | Box 74 \ 2 scan0261 | |
| Postscript memo discussing the improvement of a clutch mechanism by injecting it with castor oil. | 23th Sep 1919 | Box 74 \ 2 scan0262 | |
| Engine improvement by reducing friction on the slipper drive. | 24th Nov 1919 | Box 74 \ 2 scan0263 | |
| Adjustment of slipper flywheels, proposing to use half the number of springs to make the engine feel softer. | 26th Nov 1919 | Box 74 \ 2 scan0264 | |
| Confirming the standard procedure for adjusting slipper flywheels by reducing the number of springs. | 28th Nov 1919 | Box 74 \ 2 scan0265 | |
| Update on modifications and issues for car 1.EX, concerning the clutch, high tension wires, and thermometer fitting. | 8th Dec 1919 | Box 74 \ 2 scan0266 | |
| Inquiry regarding a pre-war consideration to reduce the weight of slipper fly-wheels for the chassis engine. | 7th Dec 1919 | Box 74 \ 2 scan0267 | |
| List of requested modifications and new parts to be fitted to chassis 2.EX. | 12th Oct 1919 | Box 74 \ 2 scan0268 | |
| Leaking clutch spigot oil valve and proposed design improvements. | 12th Feb 1920 | Box 74 \ 2 scan0269 | |
| Confirming the supply of pressed unwoven asbestos brake material and aluminium rivets. | 7th May 1920 | Box 74 \ 2 scan0270 | |
| Letter from Ferodo Limited concerning the supply of unwoven asbestos clutch material and research into plate clutch designs. | 6th May 1920 | Box 74 \ 2 scan0271 | |
| Page 2 of a letter from Ferodo Limited concerning the supply and fitting of new liners to foot brake shoes. | 8th Jan 1920 | Box 74 \ 2 scan0272 | |
| Production challenges of endless woven conical belts for a flywheel and clutch. | 19th May 1920 | Box 74 \ 2 scan0273 | |
| Receipt of parts from Vickers, Skefko, and Lucas. | 28th May 1920 | Box 74 \ 2 scan0274 | |
| Oil leaks from the clutch valve on American cars, detailing the function and adjustment of the worsted insert. | 8th Sep 1920 | Box 74 \ 2 scan0275 | |
| Instructions regarding excess oil leaking through a valve and increasing the amount of worsted in the crankshaft. | 8th Sep 1920 | Box 74 \ 2 scan0276 | |
| Suggestion for a modification to the design of the Clutch Coupling. | 14th Dec 1920 | Box 74 \ 2 scan0277 | |
| Dismissing Suggestion Y636 from A. Riddell of the Test Dept. regarding the use of springs. | 17th Dec 1920 | Box 74 \ 2 scan0278 | |
| Trial and rejection of a clutch holding-out device. | 22th Dec 1920 | Box 74 \ 2 scan0279 | |
| Design of a safety clutch catch device to replace the use of a wooden block. | 25th Aug 1919 | Box 74 \ 2 scan0280 | |
| Design of a catch for holding the clutch out. | 25th Aug 1919 | Box 74 \ 2 scan0281 | |
| Communicating Mr. Royce's disapproval of a clutch catch and cancelling instructions to proceed with schemes for it. | 8th Sep 1919 | Box 74 \ 2 scan0282 | |
| Customer-suggested wooden tee piece to act as a clutch holding-out device. | 16th Dec 1920 | Box 74 \ 2 scan0283 | |
| Letter from a customer regarding a wooden device he created for propping out the clutch. | 28th Oct 1920 | Box 74 \ 2 scan0284 | |
| Letter to a customer regarding a wooden device for holding out the clutch. | 24th Nov 1920 | Box 74 \ 2 scan0285 | |
| Wooden 'T' piece for a clutch holding-out device and recommending against its use. | 22th Dec 1920 | Box 74 \ 2 scan0286 | |
| Response to an inquiry about using a wooden clip on a clutch pedal and a holding-out piece for a cotton fabric-lined clutch. | 23th Dec 1920 | Box 74 \ 2 scan0287 | |
| Adoption of new clutches and issues with Ferodo and Raybestos friction materials. | 24th Jan 1921 | Box 74 \ 2 scan0288 | |
| Failures of the chassis flywheel guard and recommending its modification or removal. | 15th Apr 1921 | Box 74 \ 2 scan0289 | |
| Cone clutch, referencing correspondence with 'Scandinavia' Belting Ltd. and requesting a despatch date. | 23th Sep 1921 | Box 74 \ 2 scan0290 | |
| Letter from Scandinavia Belting Ltd. regarding the supply of a jointless non-metallic cone clutch lining. | 22th Sep 1921 | Box 74 \ 2 scan0291 | |
| Specification sheet detailing the weights and dimensions of 40/50 and Goshawk clutch and flywheel components. | 27th Feb 1923 | Box 74 \ 2 scan0292 | |
| Modifications to the 40/50 chassis slipper flywheel, including spring numbers, friction material, and tolerances. | 3rd Mar 1924 | Box 74 \ 2 scan0293 | |
| Friction consistency, note tabulation on drawings, and implementing design alterations. | 3rd Mar 1934 | Box 74 \ 2 scan0294 | |
| Investigation into engine vibrations caused by slipper drive variations on 40/50 and 20-HP chassis, with recommendations for improved surface finishing. | 9th Apr 1923 | Box 74 \ 2 scan0295 | |
| Essential points and investigations for the 40/50 HP Slipper Flywheel. | 6th Jun 1923 | Box 74 \ 2 scan0296 | |
| The moment of inertia of EAC and 40/50 HP flywheels. | 20th Mar 1924 | Box 74 \ 2 scan0297 | |
| Comparison table of physical properties and inertia calculations for EAC and 40/50 HP components. | 2nd Jul 1919 | Box 74 \ 2 scan0298 | |
| Listing parts received from various suppliers for specific experiments. | 2nd Jul 1919 | Box 74 \ 2 scan0299 | |
| Receipt of parts for experiments from various suppliers. | 4th Aug 1919 | Box 74 \ 2 scan0300 | |
| Notification about the receipt of a spring from Geo. Salter & Co. for an experiment. | 7th Oct 1919 | Box 74 \ 2 scan0301 | |
| List of modifications and parts to be fitted to a chassis for a 10,000-mile endurance run. | 19th Nov 1919 | Box 74 \ 2 scan0302 | |
| Extract regarding experiments with clutches for the 'Hawk' and 20 HP 'Goshawk' chassis using ferodo linings. | 17th Apr 1920 | Box 74 \ 2 scan0303 | |
| Design considerations and requested modifications for various vehicle parts. | 8th May 1920 | Box 74 \ 2 scan0304 | |
| Listing the receipt of various parts from external suppliers. | 6th Sep 1920 | Box 74 \ 2 scan0305 | |
| Testing materials for disc clutches, specifically Ferodo fabrics. | 23th Nov 1920 | Box 74 \ 2 scan0306 | |
| Test report on the Goshawk I vehicle (X3481) detailing performance characteristics and issues. | 1st Jan 1921 | Box 74 \ 2 scan0307 | |
| Continued road test report discussing the engine, steering, and general impressions of the X.3516 vehicle. | 8th Jan 1921 | Box 74 \ 2 scan0308 | |
| Vibrations and gearbox performance of the 'GOSHAWK' chassis. | 1st Jan 1921 | Box 74 \ 2 scan0309 | |
| Technical report discussing improvements for the clutch, axle, and suspension systems. | 12th Jan 1921 | Box 74 \ 2 scan0310 | |
| Design considerations and issues for brakes, radiator, clutch, and springing on the 'Goshawk II' chassis. | 12th Jan 1921 | Box 74 \ 2 scan0311 | |
| Proposed designs for the Goshawk I clutch and brake pedal gear. | 10th Feb 1921 | Box 74 \ 2 scan0312 | |
| Deflection of Goshawk I foot pedals and proposing design improvements. | 10th Feb 1921 | Box 74 \ 2 scan0313 | |
| Recommendation to add a pocket with a detachable cover to the flywheel casing to prevent damage from dropped parts. | 1st Aug 1921 | Box 74 \ 2 scan0314 | |
| 150-mile road test of the Goshawk 11 chassis, detailing noise issues and planned modifications. | 1st Sep 1921 | Box 74 \ 2 scan0315 | |
| Technical report on crankshaft periods, damper friction and clutch problems. | 9th Sep 1921 | Box 74 \ 2 scan0316 | |
| Fabric-based clutch designs, comparing a Mack Truck clutch to English Leyland clutches. | 9th Sep 1921 | Box 74 \ 2 scan0317 | |
| Extract detailing a persistent clutch shudder issue on a 20-HP model, despite modifications to the driving plate. | 1st Oct 1921 | Box 74 \ 2 scan0318 | |
| Extract of design considerations for a small chassis regarding pumps, starter, governor, and clutch. | 17th Nov 1920 | Box 74 \ 2 scan0319 | |
| Outlining modifications to the small R.R. chassis specification regarding the clutch, gearbox, and couplings. | 23th Nov 1920 | Box 74 \ 2 scan0320 | |
| Dispatch of a blueprint for a revised 'Goshawk' clutch, drawing Lec.1319. | 1st Dec 1920 | Box 74 \ 2 scan0321 | |
| Adaptation of a Goshawk gearbox and single plate clutch, awaiting further drawings. | 9th Dec 1928 | Box 74 \ 2 scan0322 | |
| 'KITE' gearbox and clutch, comparing different versions and noting necessary adjustments. | 14th Dec 1920 | Box 74 \ 2 scan0323 | |
| Potential material error for the Goshawk II clutch pressure plate. | 25th Feb 1921 | Box 74 \ 2 scan0324 | |
| Brinell hardness specification and manufacturing process for the Goshawk 11 clutch plate. | 18th May 1921 | Box 74 \ 2 scan0325 | |
| Coefficient of friction and performance issues of graphite-impregnated Ferobestos used in the Goshawk 11 clutch. | 23th Aug 1921 | Box 74 \ 2 scan0326 | |
| Increasing clutch spring pressure to prevent slippage and requesting views on the resulting pressure on the disc material. | 23th Aug 1921 | Box 74 \ 2 scan0327 | |
| Co-efficient of friction for Ferobestos clutch material with and without graphite for the Goshawk 11 flywheel clutch. | 24th Aug 1921 | Box 74 \ 2 scan0328 | |
| Solutions for clutch plate warping in the Goshawk 11 engine. | 9th Sep 1921 | Box 74 \ 2 scan0329 | |
| Ideas for cast iron wheels with curved spokes and single plate clutches. | 7th Sep 1921 | Box 74 \ 2 scan0330 | |
| Chassis improvements, specifically an over-running clutch disengagement issue and a new clutch plate design. | 14th Sep 1921 | Box 74 \ 2 scan0331 | |
| Clutch design, comparing single and multi-plate options and material choices. | 14th Sep 1921 | Box 74 \ 2 scan0332 | |
| The materials used when refitting Ford clutches and re-actance brakes to avoid transmission damage. | 14th Sep 1921 | Box 74 \ 2 scan0333 | |
| Drawing No. LeC.1446 showing five schemes for the Goshawk 11 clutch plate. | 15th Sep 1921 | Box 74 \ 2 scan0334 | |
| Material change for the Goshawk II flywheel from mild steel to cast iron. | 9th Sep 1931 | Box 74 \ 2 scan0335 | |
| Instruction from Mr. Royce to use a forged flywheel over a cast iron one for the Goshawk II engine. | 20th Sep 1921 | Box 74 \ 2 scan0336 | |
| Use of cast iron versus steel for the Goshawk 11 flywheel and clutch back piece. | 31th Oct 1921 | Box 74 \ 2 scan0337 | |
| Shuddering issue with the Goshawk 11 clutch and specifications for replacement Ferodo linings. | 1st Oct 1921 | Box 74 \ 2 scan0338 | |
| Testing of Ferodo bonded asbestos clutch linings for the Goshawk II project. | 12th Oct 1921 | Box 74 \ 2 scan0339 | |
| Letter from Ferodo Limited regarding the supply of Goshawk 11 Clutch Discs and a discussion on clutch shudder. | 11th Oct 1921 | Box 74 \ 2 scan0340 | |
| Extract discussing clutch shudder issues on low gear and reverse, its potential causes and solutions. | 17th Oct 1921 | Box 74 \ 2 scan0341 | |
| From Royce detailing suggestions by Hives to address engine roar and improve the chassis. | 3rd Nov 1921 | Box 74 \ 2 scan0342 | |
| Drawings for an improved type of clutch thrust bearing for the Goshawk 11. | 18th Nov 1921 | Box 74 \ 2 scan0343 | |
| Extract from a report detailing experiments on clutches, comparing a standard clutch with Ferodo bonded asbestos against Ferobestos. | 1st Jan 1922 | Box 74 \ 2 scan0344 | |
| The standard clutch spring for the Goshawk 11 engine. | 9th Mar 1922 | Box 74 \ 2 scan0345 | |
| Double spring scheme for the Goshawk clutch, referencing drawing No.LeC.1564. | 5th May 1922 | Box 74 \ 2 scan0346 | |
| The performance of newly fitted clutch springs for the GOSHAWK TWO. | 11th May 1922 | Box 74 \ 2 scan0347 | |
| Approving a blueprint for a Goshawk clutch spring and requesting three samples. | 30th May 1922 | Box 74 \ 2 scan0348 | |
| Note confirming the dispatch of clutch springs and caps for the Goshawk car. | 1st Jun 1922 | Box 74 \ 2 scan0349 | |
| Delay in supplying Goshawk II clutch springs due to a lockout. | 7th Jun 1922 | Box 74 \ 2 scan0350 | |
| With a sketch, inquiring about the incorporation of a centering bush in the Goshawk clutch. | 12th Jul 1922 | Box 74 \ 2 scan0351 | |
| Modifications and cost-saving improvements to the Goshawk clutch mechanism. | 19th Jul 1922 | Box 74 \ 2 scan0352 | |
| Two points for an instruction book regarding clutch adjustment and oiling. | 21th Jul 1922 | Box 74 \ 2 scan0353 | |
| Modifications to the Goshawk Clutch Mechanism and associated blueprints. | 21th Jul 1922 | Box 74 \ 2 scan0354 | |
| Modifications to riveting Ferodo fabric on Goshawk II clutch plates. | 10th Aug 1922 | Box 74 \ 2 scan0355 | |
| Recommendation to fit production chassis with a longer clutch lever to reduce the pressure required. | 9th Sep 1922 | Box 74 \ 2 scan0356 | |
| Specification sheet detailing the weights of the 40/50 and Goshawk clutch and flywheel components. | 27th Feb 1923 | Box 74 \ 2 scan0357 | |
| Query regarding the wear rate of Goshawk 11 clutches and the results of destruction testing on various Ferodo fabrics. | 28th Feb 1923 | Box 74 \ 2 scan0358 | |
| Wear rate and coefficient of friction of Ferodo clutch material used in a Goshawk Clutch. | 1st Mar 1923 | Box 74 \ 2 scan0359 | |
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