By Jenni Wirtz | 9 May, 2018
With Spring finally upon us, 1000’s of iconic classic vehicles will be receiving some TLC in preparation for this year’s show season. Although some of the work will be undertaken by competent owners, others will use an independent workshop, which when presented with a classic, should respect the originality of the vehicle and fit brands that were used in the vehicle’s original manufacture. When it comes to the clutch, 80% of all British-built cars were fitted with Borg & Beck, so for the replacement items original Borg & Beck really is the best option.
Although similar in operation to current clutches, when the clutch itself needs replacement, many will not have worked with these early designs. However, the company’s in-house Classic Clutch engineer provides the following advice when carrying out replacement of an ‘A’ or ‘AS’ type Borg & Beck clutch.
The ‘A’ type is usually of a single dry plate design comprising a cover assembly, driven plate assembly and release bearing, which utilises a pressure plate that is driven by the pressed steel cover via machined pressure plate lugs engaging into slots.
The ‘AS’ design features a pressure plate driven by the pressed steel cover via a number of tangentially disposed spring steel straps in pairs. These deflect during clutch operation, without disturbing the concentric position of the pressure plate. One end of each pair of straps is riveted to the cover flange, while the other end is bolted to the pressure plate. This design eliminates friction between the cover and pressure plate.
In the original Borg & Beck clutch service manuals it was advised to carry out a full inspection of the clutch system as part of the vehicle’s maintenance schedule as outlined here.
Removal of the clutch assembly from the vehicle
- Loosen each of the bolts securing the clutch to the flywheel, but to avoid distorting the cover flange, slacken them a turn at a time, diagonally, until the pressure of the clutch springs is relieved. Then remove the bolts and complete clutch from the flywheel, all parts, except the driven plate remaining assembled to the cover.
- Inspect the flywheel – scoring may occur on the face of the flywheel in which case it must be re-ground or replaced as even slight scoring will cause excessive wear of the clutch facings.
- The complete dismantling of the clutch was also advised in the original schedule, however this is not advised today. It is more viable to replace the whole unit rather than dismantle the ‘A’ & ‘AS’ type assemblies to service the individual components, as this can be both time consuming and dangerous if a technician has not opened one up before, as it is fully loaded with springs.
- When fitting the clutch back onto the vehicle the principles employed in the past still resonate today – use a driven plate alignment shaft – as misalignment is responsible for almost every case of rapid spline wear, broken drive plates, damaged transmission bearings and gears.
- As always, ensure the gearbox is adequately supported and not permitted to hang on the clutch, as serious damage may result. When guiding the gearbox into the assembly position, get the first motion shaft in true alignment with the driven plate hub and turn the main output shaft each way slightly – with gearbox in gear – to ensure smooth engagement of the splined parts. A light smear of grease should be placed on the shaft prior to installation of the gearbox.
- Once installed check the clutch pedal adjustment – in accordance with the vehicle manufacturers instructions.
Borg & Beck is an iconic brand in the world of automotive components, with more than a century’s worth of original equipment (OE) heritage when it comes to the design and manufacture of Clutch systems and components. As the original supplier of Clutch to the majority of British built vehicles dating back to 1930, the Borg & Beck brand is world renowned and today offers the aftermarket a comprehensive range of Classic Car components.
As well as providing over 40 Classic Clutch references catering for more than 200 applications, many of which would have had Borg & Beck Clutches fitted as original equipment, Borg & Beck’s comprehensive product portfolio of over 60 product lines provides multiple solutions for various classic car applications, including the much loved iconic classics such as the Aston Martin DB4, Jaguar E Type, Morris Minor and the Triumph TR range.