Getting ready to install the pressure plate on an Aluminum flywheel. I dont have any torque specs for this setup. The bolt size is 3/8-16. I did the search and came up with, 12-18 ft lbs would be in the ball park. This sounds low, even for an aluminum flywheel. Am I on the right track here?
I bet if you just add a dab of blue Locktite to the threads and bolt it down really snug you will be ok. I did one years ago like this and it turned out fine.
I plan on using locktite. Just wondering if the barely snuged up 12-18 ft. lbs. is accurate for an aluminum flywheel.
Are there inserts in the flywheel, or are you bolting into aluminum threaded holes? If they are aluminum threaded holes, then I wouldn't go past snug either, with Loctite.
Cap screws threading into aluminum may require reductions in torque of 30% or more of grade 5 capscrew torque. The bolt must maintain 2 capscrew diameters of thread engagement. 3/8" x 16 Hex-head Capscrews Grade 5, plain and non-coated 31 ft pounds and + or - 30% torque. Plated grade 5 bolts are 23, and + or minus 30%. Grade 8 bolts are plain 44, and plated are 33, both to include the + or - for aluminum applications. If the flywheel has been heli-coiled or have steel threaded inserts, than no reduction is required. TR
I would like to clarify, the torque specs given above - are for clean and dry threads. Torque is of course reduced with various lubricants, and YES Loc-Tite actually lubricates until it sets up and drys. Plain engine oil for example will generally reduced torque requirements by 10%. TR
Did you get the aluminum flywheel with the intention of being nice to it? Fidanza recommends stock torque specs with their aluminum flywheels. http://www.mossmotors.com/graphics/products/instructions/901-000.pdf Hayes has recommendations for 5/16 and 3/8 cluthc bolts here. http://prestoliteperformance.com/Po...lation_Troubleshooting_Clutches_Flywheels.pdf loctite >>may<< keep a bolt from turning and loosening. But bad things can happen even if the bolt or nut does not turn or"loosen." http://www.boltscience.com/images/boltf6.jpg Insufficent torque means reduced clamping forces and that means surfaces can slip, wear, and awful things to happen next week, even in doweled or keyed joints. http://www.aircooledtech.com/8_doweling_crank/4-dowels2.jpg http://memimage.cardomain.com/ride_images/1/1185/4241/2962120001_large.jpg http://www.miata.net/garage/hsue/Loctite Crank Fix - Part 1_files/crank5.jpg Fairly low grade Aluminum thread engagement of 2 diameters develop full strength of a grade 8 bolt and allow full torque. For charts of what UNBRAKO felt in 1996 were reasonable tapped hole thread strength to consider for a quality socket head capscrew into brass, aluminum, cast iron and mild steel, look at page 66/68 here - http://www.dalecompany.com/pdf/UNBRAKO.pdf often usually 5/16"
Thanks you all for the information. Sounds like a grade 8 bolt, plated; using loctite on an aluminum flywheel with aluminum threaded holes would require a torque of about 20 ft lbs.
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