84TAProject

Okay, a friend of mine was installing underdrives on his car, and took the balancer off to get one of the pulleys off, and in the process of using a balancer puller, burred or bent the first thread on the crank, preventing the bolt from going back in. It is a fine thread bolt. What to do with that? He is going to try sanding the beginning of the thread to remove the burr, and says he can feel a burr on it, and the bolt wont even start to go in. What options is there for this? Is sanding the thread a good idea? How about using a tap to redo the threads? What would you guys do, I personally am clueless myself.

How would you personally fix the thread to get a bolt in there? It is an immense amount of work to put a new crank in, and I doubt it needs to go that far, Im sure someone has done this before and figured it out. Thanks for the help guys, hes trying to get the car running for tommorow afternoon, and I may go over there to take a look tommorow morning (hopefully with some solutions in mind). Thanks a bunch.

mystikkal_69

iTrader: (2)

i would use a tap to "clean" up the thread(s). the same thread size not a new one. be very careful and make sure it's going in straight or your going have serious problems.

Vader

Get a 7/16-20 plug tap and chase the threads. Use kerosene or thin oil as a tap lubricant, or get a small bottle of Tap Magic" wherever you purchase the tap. Incidentally, a tap handle will allow a lot better control and a straighter alignment than trying to start or turn the tap with a wrench. Add that to your shopping list, too.

BTW - the 7/16-20 thread is standard in a SBC V-8 or many Chevy V-6s. Which engine is this on? Maybe you should match the tap to the bolt when you go shopping.

84TAProject

My friend fixed the problem this morning, he got a tap for it. The motor was a 3.8 ford in his mustang. He had to tap the threads, and was pretty worried that he killed it. He got it right the first time without using oil and doing it by hand. Am I that brave? Nope.

Yeah I know its not thirdgen related (except that mustang knows it place, and it wont touch the t/a) but I owed him a favor after he spent 6 hours under the hood with me helping me pull a cylinder head.

Thanks for the help guys.