Installation instructions for lightweight flywheelsClutch assembly guideTransmissionClutch installationNote
Installation instructions for lightweight flywheels in conjunction with the original as well as tuning clutches
Here you will learn how to proceed step by step to install our lightweight flywheels or clutch set.
Assembly:
The flywheel must be mounted on the crankshaft and aligned according to the drilling pattern (often not symmetrically arranged)
Then it must be checked that the flywheel lies flat on the crankshaft.
Crankshaft Bolts
Ensure that these are screwed straight into the thread.
Initially, tighten by hand and then "cross-tighten" evenly to 116Nm with a torque wrench. (1st stage approx. 65NM - 2nd stage 116NM)
The friction surface (both organic and sintered) is equipped with a "spring basket".
To avoid impairing the function of the clutch, the friction disc must be mounted with the spring basket side facing towards the flywheel.
The friction disc is centrally aligned on the flywheel using a centering pin (not included in the delivery).
Then the pressure plate is pressed onto the pins of the flywheel and screwed on.
Make sure that the friction disc is centered if no centering pin is available for installation.
Screw the pressure plate with the cleaned screws (see above).
Proceed as follows:
1. Initially, screw in all screws of the clutch pressure plate exclusively by hand. Check that no screw hits the back or gets blocked in the thread. The pressure plate must lie completely and flat on the flywheel. If you encounter unusual early or hard resistance, stop the assembly immediately and check the screw length again. The pressure plate must never be pulled onto the flywheel with screws.
2. Screw in the screws crosswise and evenly until the pressure plate lies flat on the flywheel (uneven screwing can lead to tension)
3. Tighten all screws evenly with a torque wrench to 25NM.
To ensure that the kit is installed correctly, we recommend mounting the gearbox and then turning the engine by hand. If installed correctly, everything will move freely, and installation can continue. We point out that installing with an impact wrench can damage the threads of the crankshaft and flywheel.
INSTALLATION OF THE CLUTCH
!!CAUTION!!
Plastic-coated release bearings must not be greased.
The clutch disc must be aligned with a suitable centering tool to the flywheel.
Mount the clutch pressure plate in the correct position on the flywheel using the locating pins.
For truck clutch pressure plates, centering is done via the centering diameter of the pressure plate housing. The correct fit of the clutch pressure plate and the flywheel must be considered.
Screw the clutch pressure plate crosswise with the manufacturer's specific tightening torque.
During gearbox installation, ensure that the gearbox slides smoothly into the clutch disc splines and that the hub is not damaged.
If increased effort is required, the gearbox shaft may need to be realigned. Use a transmission jack to avoid flanging the gearbox without support and at full weight. Ignoring this can damage the clutch system.
Screw the gearbox according to manufacturer specifications.
Bleed the release system or adjust the clutch cable/clutch pedal according to manufacturer instructions.
ADDITIONALLY CHECK!!
Engine mount gearbox mount
Propeller shaft bearing/hardy disc/drive shaft mounting
Crankshaft vibration damper
This installation guide is provided as a recommendation/help. Only the installation instructions from the vehicle manufacturers are binding!
Questions and Answers
Please note the following instructions to ensure that the clutch functions and is installed correctly
Why do I need to break in my clutch?
The principle of a clutch works similarly to that of a brake system. The different materials/surfaces must adapt to each other first. This occurs through friction. With standard clutches or organic linings, this happens relatively quickly as the lining material is "softer" than with sinter-metal linings.
What is the best way to proceed?
The correct "break-in," especially with a sinter-metal disc, requires sensitivity during start-up. The disc is sensitive to prolonged slipping or high revolution during start-up.
It is important to treat the clutch gently during the first hundred kilometers. Engagement should be quick and not too abrupt. We recommend moving the vehicle carefully in stop-and-go traffic. The procedure should be repeated a maximum of 3 times to avoid overheating the clutch.
How will I know when my clutch has worn in?
The initial clutch engagement processes are noticeably less comfortable and can be slightly rough. The feeling will improve as the linings gradually adjust. After about 500 km of mixed driving (city, country, and highway), the set should be worn in.
What do the springs (torsion springs) in the clutch disc do?
The springs help absorb torque peaks and thus protect the engine and transmission. The springs do not assist (!) during start-up.
Why are sinter-metal discs "harsher" than organic discs?
The material of the linings is crucial for power transmission. Since the friction coefficient of a sinter-metal lining disc is significantly higher than that of an organic disc, it can transmit more power. A higher friction coefficient also means a higher resistance when the linings slip, which in turn affects the feeling during engagement. The number of sinter pads is crucial for power transmission and comfort during start-up. More pads -> more comfort -> less wear
Why doesn't my pressure plate fit the flywheel?
If the pressure plate does not fit the flywheel, it might be the wrong variant. At Sachs Performance, there are two different types of pressure plates depending on the vehicle:
Pressure plate based on the original flywheel
Pressure plate based on the Sachs Performance flywheel
It is important to check whether the pressure plate used is indeed intended for the original flywheel. A pressure plate designed for the Sachs Performance flywheel does not fit on the original flywheel.
Therefore, always make sure to use the appropriate pressure plate. If you use an original flywheel, you must use the pressure plate developed based on this flywheel. This is absolutely necessary for correct function and safe installation.
Why is the starter making a grinding noise with the new flywheel? What could be causing this? The installed starter is still the original one?
A grinding noise when starting typically does not indicate a defect in the starter itself but problems with the interaction between the starter and the flywheel. Typical causes are:
Installation position/distance problem
The starter is not sitting correctly or was installed with the wrong screws. Some Opel starters require spacer plates/shims. If these are missing or incorrectly inserted, the pinion sits too deep or too shallow in the ring gear. The result is rubbing or jamming during engagement.Wear on the starter pinion or flywheel
Even with low mileage, the pinion can be worn, e.g., due to repeated cranking. Combined with a new flywheel, this can lead to grinding noises. Additionally, check if the new flywheel is cleanly deburred.Incorrect position due to clutch or transmission
Even small deviations during installation (e.g., due to incorrectly centered clutch or bellhousing) can cause grinding or grinding noises.
👉 Important: Check the play and engagement of the starter pinion –
General Information
Please read the instructions and notes carefully to avoid errors.
The assembly must only be carried out by qualified professionals or a workshop.
We do not assume any warranty and guarantee for improper installation of the parts. Please check the delivered goods to ensure they really fit your vehicle, as well as the bolt length of the crankshaft, and the SAC of the pressure plate (if available in the set), which must be completely reset.
Important: Before installation, be sure to compare the solid flywheel with the originally installed dual-mass flywheel for all relevant dimensions to ensure compatibility and functionality. An exchange of parts is only possible if they do not show any assembly marks and are returned cleanly packaged.
Installation Aid
Please pay attention to the following instructions to ensure that the clutch is installed properly.
Preparation:
CAUTION: Check the screw length of the clutch pressure plate!
The design of the original flywheel may differ from the design of our lightweight flywheel. While the original flywheel may have blind holes for mounting the clutch pressure plate, the lightweight flywheel may have through holes. Therefore, the original screws should not be used without verification.
Be sure to check the screw length before installing the flywheel. To do this, test fit the clutch pressure plate on the flywheel and fully screw in the designated screws by hand. Check how far the screws protrude from the back of the flywheel and whether there is sufficient clearance for the later installation.
The screws must securely fasten the clutch pressure plate and have sufficient thread engagement length. At the same time, they must not touch the crankshaft, crankshaft flange, engine housing, or other components on the back of the flywheel.
If a screw reaches a firm stop before the clutch pressure plate is completely and flatly seated on the flywheel, it must not be tightened further. Further tightening can warp, deform, and permanently damage the flywheel.
In this case, only use screws with the correct thread, suitable strength class, and correct length. Screws must not be adjusted with additional washers, self-cutting, or other makeshift solutions.
The friction surface of the flywheel, the threads of the crankshaft, the crankshaft bolts (only if they do not have thread locking), and the clutch bolts must be cleaned with a cleaner (e.g., brake cleaner) to remove grease, dirt, and dust; otherwise, the clutch may slip after installation. The screws with thread locker must be "medium" coated.
