SITRAK WG99211615011 COVER CLUTCH
Product Specifications
| SITRAK | WG99211615011 |
The COVER CLUTCH is the pressure plate assembly — also called the clutch cover — that bolts to the flywheel face and provides the clamping force that presses the clutch disc friction material against the flywheel surface, transmitting engine torque to the transmission input shaft during normal driving. The assembly consists of a pressed steel cover housing bolted through its outer flange to the flywheel, a cast iron or steel pressure plate that bears directly against the clutch disc, and a diaphragm spring — a single Belleville-type conical spring disc with radially cut inner fingers — that stores the mechanical energy required to clamp the disc between the pressure plate and flywheel at approximately 6,000–12,000N of clamping force depending on the vehicle's torque rating. When the clutch pedal is pressed, the release bearing pushes against the diaphragm spring fingers, inverting the spring's cone angle and lifting the pressure plate away from the clutch disc to disengage the drivetrain. The diaphragm spring design provides a self-servo characteristic — as the friction material wears and the disc becomes thinner, the spring geometry changes to increase clamping force slightly, partially compensating for wear and maintaining consistent pedal effort throughout the disc's service life.
This unit — SITRAK WG99211615011 — is manufactured to OEM-equivalent specifications: cover flange bolt circle diameter and hole count for flywheel attachment, pressure plate contact face diameter and flatness tolerance, diaphragm spring rate and clamp load at the designed release bearing travel, finger tip diameter and height for release bearing engagement, and overall assembly balance class are matched to the original part. Supplied as a complete pressure plate assembly ready for installation. Available wholesale from 150.42 USD, MOQ 1 pcs, production lead time 30-45 days.
Pressure plate assemblies fail through diaphragm spring fatigue — the spring loses its calibrated load after high cycle count use, producing a clutch that slips under full throttle loads despite the friction material having serviceable thickness remaining; through pressure plate contact face scoring and heat checking from clutch slip events that generate temperatures exceeding the cast iron's thermal limit; and through cover housing distortion from the same overheating events that crack the pressure plate welds and shift the diaphragm spring's seating geometry. A slipping clutch that has overheated the pressure plate and flywheel cannot be restored by disc replacement alone — both the disc and pressure plate must be replaced, and the flywheel must be inspected for heat checking and surface distortion before a new disc is installed against it.
- Support the transmission independently on a transmission jack before unbolting it from the engine — a manual transmission weighing 40–80 kg will drop when the last bellhousing bolt is removed; lower it slowly and guide the input shaft clear of the clutch disc hub spline to avoid bending the disc damper springs or scoring the release bearing collar guide sleeve on withdrawal.
- Inspect the flywheel face thoroughly before fitting the new pressure plate — examine the full contact area for heat checking (a fine network of radial and circumferential cracks), blue or brown discolouration indicating overheating, deep scoring grooves, and surface hardening evidenced by a glazed, mirror-polished zone; a flywheel with heat checks or surface hardening cannot provide consistent friction to a new disc and must be machined or replaced; fitting a new clutch to a damaged flywheel will reproduce judder from the first engagement.
- Use a clutch alignment tool to centre the disc hub precisely on the crankshaft pilot bearing before tightening the pressure plate bolts — the input shaft must pass through the disc hub spline and into the pilot bearing simultaneously during transmission installation; a disc that is off-centre by more than 0.5 mm will prevent the input shaft from entering the pilot bearing, requiring the transmission to be partially lowered and the disc repositioned; do not attempt to force the shaft through a misaligned disc.
- Tighten all pressure plate cover bolts in the specified spiral sequence in three passes — first pass hand-tight, second pass to half the final torque, third pass to the OEM torque value; tightening in a random sequence or fully torquing individual bolts before others distorts the cover housing, shifting the diaphragm spring seating geometry and producing the same uneven clamping force as a heat-damaged cover; typical torque values are 18–25 Nm for passenger car applications.
- Apply a small amount of high-melting-point grease to the input shaft spline — not molybdenum disulphide paste, which migrates onto the friction faces — at the disc hub contact zone before inserting the shaft; the spline must slide freely to allow the disc to centralise during engagement; a dry spline that corrodes in service produces a disc that sticks on the spline under light load, causing a dragging clutch symptom that appears identical to a failed pressure plate.
- Install the new COVER CLUTCH (SITRAK WG99211615011), reinstall the transmission, torque all bellhousing bolts to OEM specification in the diagonal sequence, reconnect the clutch hydraulic or mechanical linkage, bleed the clutch hydraulic circuit, adjust pedal free play on mechanical linkage systems, start the engine and verify no clutch judder during gentle take-off, no slip under firm acceleration in third gear, and correct pedal feel and travel before returning the vehicle to service.
| Part | Reason for Combined Replacement |
|---|---|
| Clutch Disc OEM ref. varies by engine torque and transmission | The clutch disc and pressure plate are a matched friction pair that must always be replaced simultaneously. A new pressure plate paired with a worn disc has uneven friction material distribution that causes the pressure plate to make full contact on the thicker worn areas and no contact on the thinner unworn areas, producing immediate judder and accelerated wear on both components from the first engagement cycle. |
| Release Bearing OEM ref. varies by transmission type | The release bearing contacts the pressure plate diaphragm spring fingers thousands of times per year on every clutch pedal depression. Its bearing and thrust face accumulate fatigue at the same rate as the disc and pressure plate over identical mileage. Replacing the release bearing simultaneously with the pressure plate and disc eliminates a bearing noise failure within a short interval that would otherwise require a repeat transmission removal. Every reputable clutch kit includes the release bearing for this reason. |
| Flywheel OEM ref. varies by engine and transmission | A flywheel that has been subjected to the same slip events that destroyed the pressure plate will have heat checks, surface hardening, or flatness deviation that causes judder with any new clutch disc. Inspect the flywheel face at every clutch service — if any defect requiring more than light resurfacing is found, or if the remaining material after resurfacing would be below minimum thickness, replace the flywheel simultaneously with the clutch kit to restore the complete clutch system to new condition. |