Because of standard OEM factory manufacturing tolerances, the aluminum flywheel to crankshaft fit may vary from slip to interference. If an interference is present, check to see that when the flywheel bolts are torqued, the flywheel is pulled tight against the mating crankshaft surface. Remove the flywheel and inspect for evidence of proper fit. Excessive flywheel run-out is the evidence of improper fit. Interference at the crankshaft 'boss' can be corrected by removing excessive material with a 3 cornered scraper or by heating the flywheel on an electric 'hot plate.' Never leave the hot plate unattended. Aluminum expands at twice the rate of steel so that in order to retain a tight fit when the engine and flywheel gets hot, the aluminum flywheel has to go on tighter at ambient temperatures for a proper tight fit at running temperatures. Test the flywheel and clutch that you plan to use for rotational clearance inside of the bell housing and to the engine for clearance before final assembly. Normal manufacturing tolerances with the factory bell housings, oil pan, sensors, engine blocks, and or any other area that could cause clearance problems must be checked. The flywheel application has been derived using the best possible sources. The end user must verify fitment before installation.
For vehicles equipped with sensors triggered off of the flywheel, measure the clearance between the flywheel and trigger before removal of the original flywheel. This clearance must be matched after installation of your new flywheel. This may require shimming for clearance or moving the senor in. Failure to do so will result in a vehicle that runs poorly or not at all. Apply a small amount of Loctite to the OD of your pilot bearing when installing it in your new flywheel. The fit is not as tight as your OEM steel flywheel as the aluminum flywheel and steel bearing heat differently. The flywheel must be designed this way to work properly. Clutch threaded bolt holes are USS (coarse thread) or standard Metric as this is stronger for aluminum. If your flywheel uses dowels for the clutch, the dowels should be pressed in with a vise. You must apply a small amount permanent Loctite on each dowel before installation. Follow the OEM specifications for the flywheel to crank bolts and torque the clutch mounting bolts to OEM Specifications. Wipe the friction surface with brake cleaner to remove protective film.
Since this is a CNC machined aluminum flywheel, it is very close to the correct balance, but you should always check the balance with your clutch pressure plate and your particular engine - especially if it is an external balance configuration.
Do not use Loctite on the crank register because it prevents the flywheel from properly seating against the crank. Dual Mass replacement flywheels may cause added gearbox noise. This is a normal effect that is well worth the added performance. The noise comes from the idler gears and does not pose a premature wear problem.
Inspect flywheel whenever possible for fatigue cracks. Some of the most critical areas to inspect are:
Extreme heat can adversely affect the dowels and ring gear. For performance use vehicles special dowels are available. Extreme heat can, as with any flywheel, affect the ring gear causing the ring gear to grow and not return to it’s static diameter. Precautions must be taken in performance use vehicles for this situation. The use of a scatter shield for the clutch and flywheel area is a must in all performance use vehicles. High Performance parts and Service excluded from warranty. Due to the unusual stress placed on racing parts, and because of the circumstances under which they are often used, racing parts are sold without warranty, as is, and all warranties, express or implied, of merchantability, or of fitness for a particular purpose, or otherwise are expressly disclaimed and denied. See reverse side for specific number instructions and policies.