| Author | Message | ||
     Kenb |
I'll start from the top. Bought bike with 16k mi on it. Brought to dealer for recall work, none had been done by PO. Dealer did recall work and said there was a blown head gasket. Took engine apart and found rear headbolts loose on rear cylinder and headgasket burnt through on left side. Reassembled engine with new gaskets and torqued headbolts as per spec in book (1/4 turn past 15 ft lbs). 19k miles noticed some weeping from base gasket on rear cylinder. Grabbed 1/2" wrench and checked exposed headbolts, loose. Engine was hot when checked. My plan is to get a flex head 1/2" 12 point socket(to reach headbolts under rocker cover) and tighten all head bolts to 35 ft lbs. Anybody see any problems here ? I remember once upon a time when you ALWAYS retorqued head bolts after a few heating/cooling cycles but the manual says nothing about doing this. Thanks Ken | ||
| Spiderman |
Well as for the first time I can't tell ya why they were or came loose could be a few things. But when you did it did you oil the bolts and if so how much? If you put an excessive amount of oil on the bolts it can pool and cause them to come loose. Also your head or cyl may be warped I would check that also. Good Luck | ||
| Kenb |
I usually grease any and all threads that don't call for loctite. I hate seized or galled bolts. You don't see a problem with just retorquing do you ? | ||
| Spiderman |
I think I found your problem You don't grease the threads you put 20/50 H-D oil on the flange and outside of the bolts. The man. does not say to use anything on the threads at all. | ||
| Newfie_buell |
I may be wrong but wouldn't greasing or heavily oiling the threads give improper torque readings on the wrench? Where is our mathmetician Blake when we need him??? | ||
| Mikej |
Clean and dry unless otherwise prescribed as a general rule of thumb for true torque values. YMMV. | ||
| Mikej |
http://www.norbar.com/pdf_files/TorqueValueGuide.pdf http://www.norbar.com/FAQ.htm#TorqueValueGuide edited by mikej on July 09, 2003 | ||
| Jssport |
Generally use anti-seize on the threads, light 10 wt oil on the bolt flanges. | ||
| Imonabuss |
Any change in surface friction coefficient will affect the relationship between torque and bolt load. So, if you are given a torque reading for a dry clean thread, DO NOT use that same value for that fastener after you have oiled it or used anti-sieze, and also not if the bolt is all grungy. For a given torque the bolt load will be higher if lubricated, lower if the threads are dirty. So, if you decide to lube up those threads to get a smooth torque reading, don't be surprised when the bolt breaks somewhere down the road (or even while you are tightening it!). For real accuracy, turns in from finger tight is better; fasteners that give you actual applied tensile joint force best of all. But in the real world where time requires use of a torque wrench, you are best off using clean fresh fasteners prepared per manufacturers instructions, and torqued to spec. Most quality manufacturers have taken great pains to come up with a torque reading that comes closest to applying the correct tensile force. When you second guess them, unless you really know what you are doing, you are in trouble. | ||
| Jmartz |
I have done more head jobs on HD motors than I care to remember. No, I am not a mechanic but have been abusing motors since childhood, thus the need to fix them. Ever since the days of pan and shovelheads with those horrid underhead long bolts, though the early evo nut and washer to the present elongated nut, I have never had a head leak, at least not within a week of reassembly. I happened on my Buell when I used Cometic sandwich steel gaskets. The leak occurred when I failed to compress the seal ridges while using the std. factory recommended tightening technique. The nuts received only 25 ft. lbs. of torque after, 9, 15 and 1/4 turn. |
