Transmission Housings and Clutch Covers


Transmission housing provides mechanical support for gearbox components as well as a fluid-tight container to store their lubrication fluids. A quality transmission housing should be designed and constructed in such a way as to avoid leaks.

Lubricating oil passage 23 is defined by a vertical surface 20 with an S2-space, where S2 is almost perpendicular to the lower inner surface 25 through hole 17. This arrangement minimizes pressure loss during meshing gear operation that sweeps up lubricant.


A car’s transmission contains numerous parts, but one of the most critical is the bell housing. Situated between the information and engine, it protects vital components like clutch, flywheel, and torque converter in manual transmission applications as well as road conditions and the environment below. Made from aluminum, steel, or cast iron and interchangeable between engines – its placement on this part of the transmission makes all the difference for its proper function.

JEGS offers an impressive selection of transmission bell housings suitable for street and race use, both certified SFI 6.1 specifications and featuring flywheels that explode between 8,000 to 9,000rpm, depending on their application.

Many automotive bell housings are cast as one unit; however, there are a few models made as separate components. A “split housing” typically features top and side openings to access the gearbox as well as connect to the clutch and other mechanical parts; servicing this type of housing is generally simpler compared to its one-piece counterpart but incurs additional weight and cost considerations.

Castings have become an indispensable manufacturing technique in the automotive industry, producing complex parts that would be challenging or impossible to create with other methods. Die casting is an example of this manufacturing method in which molten metal is injected under high pressure into a mold with the desired part’s cavity. After solidification occurs, this material can then be machined or finished as necessary before being taken out from its mold and machined or finished as part of an assembled, semi-finished, or completed part.

CIC supplies an assortment of special casting alloys as well as more commonly-used varieties like gray iron, ductile iron, carbon steels and stainless steels used in industries spanning transport (railway, shipping, aircraft, and aerospace), heavy equipment (construction, mining, and farming), plant machinery hardware applications as well as military hardware such as military hardware applications for both government and the army applications, home appliances automobiles or any vehicle as well as power generation or industrial purposes.

Clutch Cover

A clutch cover is a metal extension that bolts to an engine, protecting critical components such as the flywheel and clutch or torque converter from harm. Sometimes, it is interchangeable for custom applications. Some clutch covers even feature features to facilitate cooling or facilitate quick clutch adjustments between laps – perfect for road or racing use!

A clutch cover can be constructed of aluminum, cast iron, or steel material and serves to support and regulate pressure exerted by diaphragm springs or coil springs in order to press against clutch discs to transmit power from transmission systems. Proper maintenance of this component of transmission systems is essential to their optimal performance and may ensure maximum performance levels are attained.

Suppose a diaphragm spring is misaligned with its release bearing. In that case, more force will be necessary to press the clutch disc against the flywheel and generate more heat, potentially leading to damage to the clutch disc and transmission system components. Furthermore, damaged release bearings require replacement clutch covers;

The design of clutch covers plays an integral role in how easily they disengage a clutch. A large-sized clutch cover, for instance, uses a pull lever instead of a push lever for disengaging grips; this type of clutch cover provides greater longevity while decreasing pedal effort caused by wear and tear.

Additionally, clutch covers feature an oil passageway to introduce lubricating oil into the main housing and drain excess from the extension housing back into it. This feature helps prevent meshing gears in the main housing from sucking up too much lubricant – which could otherwise reduce transmission efficiency – leading to reduced transmission efficiency. Furthermore, clutch covers serve an additional safety function by protecting engines against debris should drive belt failure occur – so regularly replacing or renewing them as soon as there are signs of wear is wise.

Clutch Plate

The clutch plate is one of two sides between which a driven friction disc rests; it is bolted to the flywheel for rotation and contains a diaphragm spring that applies pressure when the drive is engaged – this force is applied by “fingers” at the center of the plate that apply pressure through clamping force; upon disengagement from the pedal, these fingers disengage to allow central casting of driven friction disc to lift off from the guided surface.

When engaged, the clutch plate features splines that correspond with the teeth on the gearbox input shaft; this allows it to rotate at an equal pace as both the flywheel and clutch plate, effectively transferring the torque from the flywheel to the gearbox while stopping its output shaft from spinning freely.

Clutch plates come in various forms, from Bellville styles with nine springs and three levers commonly found on racing vehicles to Borg & Beck varieties with the same number of springs but wider levers found on late model cars, and even diaphragm clutch plates, which may be found in newer models. Each type offers its own set of advantages and disadvantages depending on which application they’re being used for.

When depressing a car clutch, its throwout bearing acts to release pressure on the clutch plate, leaving it free from contact with the flywheel and permitting gearbox rotation freely. Springs in the center of clutch plates act as torsional vibration dampers for reduced power delivery fluctuations and provide smoother ride quality when driving.

The slave cylinder is connected to the clutch fork by means of a push rod, so when the clutch pedal is depressed, fluid from the master cylinder is forced through its pipe into the slave cylinder, forcing its piston outward and out, which in turn pushes out its push rod, riding upon clutch fork compressing release bearing and compressing spring; once released this pressure is released and fork returns into its normal position.

Clutch Sleeve

Transmissions are complex and expensive machines. To make sure it functions smoothly, all parts must be well maintained to keep working together correctly. Unfortunately, clutch input shaft sleeve (guide/bush) and seal are often neglected by garages, leading to expensive and frustrating failures; sometimes, broken or worn-through shaft sleeves require the entire case to be replaced, costing thousands. PDM offers simple yet cost-effective repair kits that preserve original input shaft sleeves while saving thousands on replacement costs.

PDM Solutions proposes replacing the clutch input shaft sleeve with an aluminum sleeve that fits over its predecessor and can be secured using four set screws, providing proper oil circulation. This sleeve also features a built-in bushing and seal to maintain optimal oil flow while simultaneously protecting the clutch hub from sliding off its end of the shaft, potentially leading to costly repairs of damaged cases or expensive replacement costs.

As no known art describes an intermediate sleeve that provides for relatively easy linear or translational movement of bearings such as clutch release bearings onto guide elements such as quill or transmission retainer shafts, this invention aims to develop such an intermediate sleeve.

As part of the invention, clutch housings are equipped with release-bearing sleeves formed separately from them and connected by male screw threads to female threads on their surface. A release bearing sleeve, called 46a or 46b, depending on its design, can be attached via male screw threads for quick detachment from its clutch housing counterpart via male and female screw threads forming male screw threads which match opposite female screw threads formed on its surface; furthermore a flat portion attached by pressure-fitting means is attached by pressure-fitting means to its base portion 46a; additionally an oil seal surrounded by and in sealing contact with this release bearing sleeve can automatically remove itself when detached from its clutch housing counterpart; should this happen.