Tired of bolts snapping, nuts stripping? Some tips & ideas for general info Replace, replace, replace - always go higher tensile if possible, Titanium if money is no object If a nut/bolt looks worn or rusted - junk it immediately Never hit/press/saw/grind a bolt or stud without protecting it first - Put a nut over the stud to protect the threads Steel and aluminium are not friends - once they come into contact they will try to "weld" themselves together, a process known as "Galling". Only way to slow it down is to grease the bolts 1st Oil Nuts/Bolts before fitting, it's the bolt stretching that holds it tight, not the threads Only use hex sockets (impact type), - cheapo sockets eat heads & knuckles Always replace philips head bolts with Allen key (hex head) bolts, Black Allen key bolts are usually higher tensile anyway. Use T-handles & Allen key sockets rather than the cheapo "L" shaped keys, gives better control and the chances of stripping/snapping are reduced. The good ones will have a ball shaped head Loosening tight bolts/nuts Use your left hand to hold the socket down, wack the ratchet handle with your right, if there's no room, just give the handle a quick jerk - most nuts/bolts will crack once, sometimes twice, if more - you know there's a problem. Then use slow turning to loosen till it frees up. If it still resists, let it cool for a few minutes and come back to it, forcing a sticky nut/bolt will overheat it and end up snapping, Turning it backward before proceeding helps to "clean" the threads Wheel bolts Many people think they have to tighten wheel bolts and/or studs to breaking point in order to keep the wheel from coming loose. The bolts function is to hold the wheel against the flange only, the centre piece does all the work and takes the weight of the car - NOT THE BOLTS!! Truckers use massive powerbars because the nuts and bolts are also huge, truck hubs do not have a centre flange - hence the need for massive studs and power bars Bolt torque Where possible always use a torque wrench and stick to recommended settings It's a myth that overtorqing a bolt/nut will result in a stronger joint - once a bolts recommended torque setting is exceeded, it begins to stretch and lose torque to a point where it eventually snaps - Take a bolt and a torque wrench and try it for yourself, after the max torque setting it becomes easier and easier to tighten till it snaps Torque Wrenches Never jerk a torque wrench, it gives a false reading and can damage the spring mechanism - think smoooth when using a torque wrench Lube the threads or risk getting readings based on the friction of the threads, never try to torque a bolt or nut without a washer Always use a slow smooth motion when working with a torque wrench Always unwind the torque wrench when not in use, the spring inside can lose it's tension and give crazy readings Always keep it in it's box, dust & dirt inside will also affect operation and accuracy It's best to torque in stages where multiple bolts are concerned, allows the part to clamp down evenly and the bolts chance to settle/cool etc Taps & Dies Any mech worth his salt has his own set of taps & dies and uses them all the time. I don't use the dies much, unless I can't find a replacement bolt Tap each thread and blow them out, removes rust, crud and makes sure your torque wrench gets the correct info when the bolt is oiled Some sizes you'll need: + ()= bolt/nut size M5 X 0.8 (8mm) M6 X 1 (10mm) M8 X 1.25 (12mm) M10 X 1.5 (14mm) M12 X 1.75 (17mm) Of course "Big T" sometimes puts bigger or smaller heads on bolts, luckily it's not common
Great stuff here. I've heard that hitting a rusted bolt with a hammer first will free the rust on it. Have yet to try it, though.
Tapping bolts does help free the threads, must be done carefully though, when doing nuts - never hit naked threads without protecting them with a nut 1st Heating stuck bolts & nuts can help too, let them cool 1st Penetrating oil can help in some cases but takes ages before it can reach the threads.
One last resort trick I use for stuck bolts is to slightly tighten it and then go back and loosen it again. I also tried that CR-Freeze spray with limited success.
Good stuff Kev, the age of our cars need this sort of consideration and respect. I sometimes will tighten a tad first before trying to loosen, be carefull doing this and don't swing on a bolt like there's no tomorrow because they can snap. Giving a bolt a whack with a hammer can help, just make sure you hit it 'square' so not to burr the edges of the bolt and preferably hit it only once. Another trick I use is to put a socket over said bolt then stick a short round solid piece of steel thru the middle of the socket onto the head of the bolt and then I can whack it a few times knowing that it is now impossible to burr the edges of the bolt. I agree with wheel nut torque, and cannot believe that people swing on these like they do, over the years of buying cars I have actually bent and broken stuff trying to undo them :aargh
