| Author | Message | ||
     Greg_e |
So in the ongoing "something doesn't want me to ride this year" I spent some time working on putting my engine back together. Torqued the heads down according to the instructions that came with the Cometic gaskets, and starting working on the rocker boxes. Got them set with all the bolts started, set my torque wrench to the 22 foot pounds indicated in the manual for the 4 black main bolts (first ones you are supposed to torque), tightened everything to about half way tight and then started pulling things tighter. Had all 4 to about 3/4 torque and went for the last round. Got one tightened, went to the next and pulled, and pulled, and pulled... Tink... Broke one of those bolts and it never did hit the 22ft/lb that the wench was set to. I was lucky because just enough of the bolt was sticking up to allow me to get vise grips on it, it was not difficult to turn back out so I don't know what the deal was. So the question is, are these bolts something special or are they just normal grade 8 or 10 bolts with a shoulder on the head? They don't appear to be stretch bolts so I should be able to pick up something locally. The holes will them be chased out to clean them and then I'll start over again. I'm going to put new bolts in all eight holes for fear of breaking another. | ||
| Terrys1980 |
Black Oxide 1/4-20 grade 5 or maybe just grade 2 if it broke before you got to 22ft-lbs. (Message edited by TerryS1980 on November 13, 2011) | ||
| Greg_e |
Thanks, that's what I thought except they look more like 3/8-16. I'll measure them before buying something new. | ||
| Nik |
I've found a lot of the torque values in the manual to be excessive. I too broke the rocker box bolts at the specified torque value. They should be the same as Sportster bolts. | ||
| Terrys1980 |
I looked at the wrong ones, my bad. The larger bolts are 5/16-18. | ||
| Greg_e |
22 ft/lb is nothing too serious, I'm beginning to think that most of the fasteners are just plain junk. Comparing torque specs these must have been grade 2, grade 5 should be good for 36, and grade 8 for 44 ft/lb. | ||
| Ian03xl |
Maybe the torque wrench you're using is not calibrated correctly. Has that been considered? | ||
| Greg_e |
I think it was more that these bolts come out really hard because of the loctite. I seem to remember using about three times the force to get them out so they are probably just tweaked from that process and another reason to toss them all for new bolts. | ||
| Bearracing |
Check my post in the classifieds http://www.badweatherbikers.com/buell/messages/21/ 658567.html?1321333844 I might have the bolts your looking for in my parts bin thats pictured.. | ||
| 1324 |
Having been through my XB engine several times, I can tell you to take the manual, it's procedures, and torque values with a grain of salt. I've uncovered missing steps, misinformation, and agreeing with Nik, found many of the torque values to be too high. It could be a combination of the fastener or the mating tapped holes in the aluminum, but I never achieved the full 22 lb-ft, either. Having broken very many bolts in my travels, I knew when to stop. Go by feel (using your properly calibrated torque wrench as a guide, of course); if you don't trust your feel, torque them all evenly in increments and stop when the torque stops increasing! | ||
| Danair |
Buddy did same thing with Harbor Freight torque wrench. They are grossly inaccurate. Whatever torque you're seeking should be roughly mid-range of the wrench ideally. | ||
| Greg_e |
Thanks. They are 5/16-18 which in a grade 8 tops out at about 25 ft/lb. Looking at then and trying to thread them into the bolt size checker at the auto store I can see where all of them have "stuff" on the threads making them bigger, or are all deformed so I bet this didn't help. Now finding a suitable replacement is the hard part, the only thing that most fastener stores have are regular bolts which will then require a washer. Searching for Harley rocker box bolt I get all sorts of fancy things which is strange because I assume there is a cover over the top so you can't see all that chrome. I'll go by feel, I trust it a lot more and can use my 3/8 drive ratchet which takes a huge amount of force to hit 40 ft/lb, so around 20 should be easy to predict. Going to call the dealer in a little while and see if they have 8 of the stock since that looks like the only thing I'll be able to get before the weekend. I'll run a die over the threads to clean them off and apply my own loctite, probably run a tap through the heads to make sure I don't have a binding problem. |
