Standardized charts/tables for general torque specifications for fasteners are almost always wrong for gasketed joints, joints of soft materials, and steel threaded items into various aluminum alloys. If no specification by BMW for your specific fastener/location, you can usually use standard table values. As a general rule, there are standards for all the various types of headed screws, bolts, etc. Thus, a nut & bolt may have slightly different ratings. with the same sort of variances for plating, lubrication, etc. Tables are different for NUTS nuts are rated as 8, 10, & 12 in strength. Cadmium plated parts are hardly available anymore from Europe. Separate or included in the same tables may be information if the steel parts are cadmium plated, or otherwise treated ~30% less torque is recommended for cadmium plated parts. In the DIN (German normal standards) system, bolts & nuts are assumed to be phosphate treated, no after-treatment, not galvanized. The tables have the size of the fastener (M6, M8, M12, etc.) & optimum tightening torque for the grade of metal. It will be quite rare that you would have to consult those tables.
#Bmw torque specs wheels manual
The purpose of the tables as shown in the BMW Factory Service Manual is for those rare instances when there is no BMW specification elsewhere's for torque for an item.
There are standardized tables for recommended tightening torque for fasteners. Don't even think about using non-BMW fasteners for the driveshaft U-joint, flywheel or clutch carrier, rods. In some instances BMW uses specially made & treated items. I suggest using BMW-supplied parts! A very complete list of all sorts of BMW nuts, bolts, washers, studs, and other items, is in my hardware article. see later, herein.īMW uses bolts rated stronger than 8.8 in some places, such as shock absorber mounts, brakes, rods, crankshaft-to-flywheel or clutch carrier. and in some instances you can not depend on any markings it may have. While 8.8 is now commonly available in American hardware stores, many stores carry INFERIOR bolts, often unmarked. 8.8 is a fairly strong metal and thus, after manufacturer, it results in a decently strong bolt, & that grade is quite common on BMW's. Ratings (grades) used in the German DIN system are, in increasing order of strength: 5.6 6.8 6.9 8.8 10.9 and 12.9. German bolts are marked on their heads by a number that corresponds to the over-all strength, called a Grade. Fittings from Germany are, of course, Metric-sized. metric fasteners are not coded the same for strength. for American SAE items and, in some cases, U.S. grading systems & standard torque values:įittings from Germany are specified by a grading system that is different from what is used in the U.S. There is no need to carry extra & new sizes of wrenches, if you are careful & knowledgeable. Later model BMW motorcycles are using the smaller heads.
most started with the even numbered sizes. K bikes don't generally have this problem. You likely do not have 18 & 16 mm wrenches in your Airhead tool kit! I have seen 18 mm being substituted for 19 mm 16 mm substituted for 17 mm. A dealership might have both sizes in the same box on their shelves or, perhaps you order a bolt & get one with a different head size than you expected. Torque values between systems of measurement.įoot pounds is same as pound-feet ounce-inches is same as inch-ounces.īMW has been shipping some bolts with one wrench size smaller heads, using the original part numbers. The torque value is the product of the applied force multiplied by the lever length, all as applied 90° to the direction of the force. Torque is the result of force applied, via a lever. if you have not previously, either before or after this article. Snowbum's BMW Motorcycle Repair & Information WebsiteĬlicking on them at every visit helps support this website!Ĭlicking on something inside an advertisement helps even more!