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Robert, You must have a tapered crankshaft engine. This engine has a removable hub assembly. To remove the hub, the prop should be mounted on the hub...do not remove the prop from the hub. Loosen the hub nut, using a 5/8 inch steel bar. back off the nut ( counter clockwise) as far as you can by using your hands. When the hub nut is out as far as you can screw it, hold onto the prop - pulling it away from the engine as far as it will come with one hand, and quickly smack the end of the hub nut with a 2 pound lead hammer. The mass of the prop, and the hub, will now cause the hub to separate from the tapered shaft; so you can now loosen the nut further and take off the hub assy. Now you can dis-assemble the hub assy from the prop and inspect for damage and cracks. You may want to mark the hub and prop for correct replacement location, after inspection or replacement. Replacement is the reverse of the above, with proper cleaning of the shaft, hub assy, and lubrication of the shaft before re-installation. Proper torque for a wood prop bolts is 200-220 inch pounds. Proper torque for a metal prop bolts is 30 foot pounds Installing the hub assy, with prop already attached and bolts torqued is : Old process: Using a 5/8 inch two foot steel shaft, tighten the hub nut as tight as possible by hand.... When the hub nut is seated, using a lead mallet, give the end of the steel bar two or three whacks to set the taper hub. be sure to align the pin holes so a bolt can be installed from inside, with nut on outside. ERCOUPE Service manual: January 1, 1947: Page 44, para 8, (a) quote: "Crankshaft and threads of taper shaft engine should be clean, free from gall marks, and properly lubricated prior to hub installation. (for taper shaft lubrication, Continental Motors Corp. recommends Lubriplate NO. 707 manufactured by Fisk Bros. Refining Co., Toledo, Ohio.) Exercise care to prevent cross threading nut. (If propeller hub nut becomes galled before it is completely tightened, or is difficult to remove, remove propeller from hub, and split nut with hacksaw before attempting to remove it; this will prevent damage to shaft and consequent costly repairs.) Tighten to 1200 inch-pounds, and recheck after engine run-in. For smooth operation, track and adjust propeller by paper shims to provide a 1/32 inch maximum run out. Continental C Engine Repair manual 7-63, page 27, para 6-4 Propeller Installation (I): Install the propeller, hub and nut assembly on the crankshaft, and screw the nut in. Then, tighten the shaft nut with a 5/8 inch steel bar. Two or three sharp blows with a lead mallet will tighten it securely. Make sure that one pair of locking pin holes in nut and crankshaft are aligned. Continental overhaul manual, January, 1984, page 38, 6-4 Propeller Installation; sub para i.: "Install the propeller, hub and nut assembly on the crankshaft, and screw the nut in. Torque to 200-225 foot pounds." I have quoted the preceding procedures as written in the referenced books....Even after discussing the torque value issues with Continental Service Engineers, I still have some concern that the later specifications may be too tight, causing hub cracking from excessive pressure on a tapered shaft. Ercoupe says 100 foot pounds; Continental says 200-225 foot pounds in the latest manual; while specifying two or three Sharp whacks with a lead mallet in earlier manuals. ( two or three sharp blows might produce excessive torque, also.) Who knows what a sharp blow is ??? One Continental specification may be the cause of the differences...as they list prop bolts torque of 200- 220 inch pounds ( See page 118 of the January 1984 Continental Overhaul Manual - Bolt, Propeller Hub 3/8-24 200-220 inch pounds 16.7 - 18-3 foot pounds) (A quick read might lead one to think the 200-220 was foot pounds, not inch pounds, and applied to the hub nut, not prop bolts.; but notice it applies to 3/8-24 bolts. The earlier Continental manual 7/63 lists prop bolt torque of 180-220 inch pounds. Ercoupe Manual lists prop bolt torque as 125 - 175 inch pounds ( Wood prop). page 44, para 8. McCauley lists proper torque for a metal prop 3/8 inch bolts as 25 - 30 foot pounds, page 209, Univair parts cataloge. I also recognize that a too loose hub will cause damage and potential cracking of the hub...; So, take your pick, with the best advice from your experienced engine mechanic..To torque the nut, requires the building of a special hub wrench adapted to a torque wrench. I am not aware of such a wrench being available in the market, tho it is not difficult to build one. Fly Safe - Have Fun Harry Francis N93530 Elliston, VA ============================================================================== To leave this forum go to: http://ercoupers.com/lists.htm
