If the hole in the crank is the least bit misshapen, no amount of tightening will keep it on there. Is the crank held on by a bolt or nut? Bolts are better! Also, once you get a new left crank, check the bolt or nut the first time you hear the slightest creak. That creak is your first and only warning. Then the creak stops and the arm falls off!
Go get it fixed right. I shouldn't be more than $20 out the door!
Scott Gambler, Scott Ransom, Kona Bear, Bianchi 928 Carbon/Chorus, C'Dale Rize4
I say just grit your teeth and fork out the cash for a new set of cranks and bb. get a splined set. I used to go through cranks and bb's all the time because they rounded out. I got a set from AC componets that were not supposed to do it. The guys at AC said I put them together wrong, ha. So they gave me a new set for free and installed them for me. They rounded out. They said that pair was defective gave me another set and wouldent ya know, it happend again. They gave me a free set again. Since then I have switched to KookaKranks and they are finally starting to go( after 2 hard years. Next set will be splined on all 3 bikes.