toolman Posted October 31, 2009 Report Share Posted October 31, 2009 Getting ready to weld my crank pins. My rod side clearance is .019 thousands. The manual says .0098 to.0295 thousands. should i press it tighter or just weld it like it is? Thanks Quote Link to comment Share on other sites More sharing options...
AKheathen Posted November 1, 2009 Report Share Posted November 1, 2009 if you are currently assembling the crank assembly, then go ahead and finish tightening it up just a little, if you can squeeze the extra >.009 out, but if it has been running that way previously, or you don't have the means to be that precise, then leave it alone and weld it that way. although, it doesn't sound like you are an experienced crank builder (no offense) in which case, i would just leave it as not to risk going too far, and having to figure out how to spread it again and further weaken the interferance fit. it's well within spec already. Quote Link to comment Share on other sites More sharing options...
toolman Posted November 1, 2009 Author Report Share Posted November 1, 2009 Your right I'm not a crank builder. But I'm a very experienced welder and machinist 30 years and I do have the tools to do the job. I was just asking the question without the long story. I took the bike apart for trans trouble and found the crank coming apart. the fly wheel side had opened up to .042" which was out of spec per the manual. I was going to send it out but never got it done. So A nice rainy Saturday here so I took the bearings off put it in the press measured the other side and pressed it back on so the 2 side were equal so that brought me to the question should it be tighter or what are the factory or after market cranks side clearance set at new? Thanks Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted November 1, 2009 Report Share Posted November 1, 2009 If my crank had opened up that much and I had the engine apart, I would tear the crank apart and inspect EVERYTHING, maybe throw some rod kits at it and have it trued and welded. When a crank lets go, it can fuck up alot of costly parts. If you don't have the equipment to press it apart and back together, get it phased correctly and true before you weld it, you should send it to a rebuilder or buy a rebuilt or new one already trued and welded. Sometimes it is hard to spend money when you think you can do it yourself, but if you deal with reputable people, you get what you pay for- a solid crank that will last for a long time and not fuck up the rest of your engine. Quote Link to comment Share on other sites More sharing options...
toolman Posted November 1, 2009 Author Report Share Posted November 1, 2009 Understood!!!!!!!!! I'm going to put new bearings on it and check every tolerence. I just can not afford a new crank right now and buying a used one is out you just do not know what your buying. Thanks Quote Link to comment Share on other sites More sharing options...
blowit Posted November 1, 2009 Report Share Posted November 1, 2009 Understood!!!!!!!!! I'm going to put new bearings on it and check every tolerence. I just can not afford a new crank right now and buying a used one is out you just do not know what your buying. Thanks If you have the means to press the crank properly, I would recommend bring it back down to OE min tolerance to get the best life out of it. The washers are typically what wear down over time so just pushing things back a little tighter will help you. Keep in mind that getting things too tight will deprive the bearings of lubrication. Also remember if you take the crank apart, you will need to rework the runout and phasing of the crank. IMO, not worth it on a used crank. Push it together, weld it, run it till it is done which will probably be years. Good idea to replace the outer bearings though. Easy swap.. Mull Engineering Quote Link to comment Share on other sites More sharing options...
AKheathen Posted November 1, 2009 Report Share Posted November 1, 2009 i would strongly recomend truing it first. like i said, i wasn't tying to offend. we get the same questions from the average joe. just set yourself the jig and go to town.... Quote Link to comment Share on other sites More sharing options...
toolman Posted November 2, 2009 Author Report Share Posted November 2, 2009 No offense taken. I was in a hurry with the first post and did not explain the situation fully. Does any one know what the O.E. spec's are. Also I'm going to tig weld it with .030 stainless filler rod just about a third of the diameter of the pin. This what i have seen in the past on other cranks. Is this right or wrong. Thanks Quote Link to comment Share on other sites More sharing options...
Screaming Yellow Zonker Posted November 2, 2009 Report Share Posted November 2, 2009 good luck Quote Link to comment Share on other sites More sharing options...
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