Possible stripped crank threads/bolt
3rd Gear
Joined: Feb 2020
Posts: 3
Likes: 0
From: Washington State
I know this is an old thread, but hopefully someone will be able to respond to this. If not I will make a new one.
I have a similar problem to creator of this thread, however in my case the crank bolt did not get stuck, but I believe I damaged the first couple of threads in the shaft itself. I was attempting to seat the new balancer on with the stock bolt after giving the pulley a couple of taps with a hammer to seat it in far enough to get the bolt to catch. Unfortunately, I should've just gotten a longer bolt or installation tool to get it on because as I began to turn the stock bolt I wasn't actually pushing the balancer on, it was really just damaging the threads because I didn't get the bolt in far enough. Now I can't even thread anything on. I want to do this right and make sure I never have to deal with this nightmare again, so:
Would it be okay to just tap the same size and try a longer bolt? Or should I contact a machine shop to do it professionally?
What is the pricing for a machinist to come out and do this repair?
Thank you to anyone who sees and responds to this, I appreciate your help!
I have a similar problem to creator of this thread, however in my case the crank bolt did not get stuck, but I believe I damaged the first couple of threads in the shaft itself. I was attempting to seat the new balancer on with the stock bolt after giving the pulley a couple of taps with a hammer to seat it in far enough to get the bolt to catch. Unfortunately, I should've just gotten a longer bolt or installation tool to get it on because as I began to turn the stock bolt I wasn't actually pushing the balancer on, it was really just damaging the threads because I didn't get the bolt in far enough. Now I can't even thread anything on. I want to do this right and make sure I never have to deal with this nightmare again, so:
Would it be okay to just tap the same size and try a longer bolt? Or should I contact a machine shop to do it professionally?
What is the pricing for a machinist to come out and do this repair?
Thank you to anyone who sees and responds to this, I appreciate your help!
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
I know this is an old thread, but hopefully someone will be able to respond to this. If not I will make a new one.
I have a similar problem to creator of this thread, however in my case the crank bolt did not get stuck, but I believe I damaged the first couple of threads in the shaft itself. I was attempting to seat the new balancer on with the stock bolt after giving the pulley a couple of taps with a hammer to seat it in far enough to get the bolt to catch. Unfortunately, I should've just gotten a longer bolt or installation tool to get it on because as I began to turn the stock bolt I wasn't actually pushing the balancer on, it was really just damaging the threads because I didn't get the bolt in far enough. Now I can't even thread anything on. I want to do this right and make sure I never have to deal with this nightmare again, so:
Would it be okay to just tap the same size and try a longer bolt? Or should I contact a machine shop to do it professionally?
What is the pricing for a machinist to come out and do this repair?
Thank you to anyone who sees and responds to this, I appreciate your help!
I have a similar problem to creator of this thread, however in my case the crank bolt did not get stuck, but I believe I damaged the first couple of threads in the shaft itself. I was attempting to seat the new balancer on with the stock bolt after giving the pulley a couple of taps with a hammer to seat it in far enough to get the bolt to catch. Unfortunately, I should've just gotten a longer bolt or installation tool to get it on because as I began to turn the stock bolt I wasn't actually pushing the balancer on, it was really just damaging the threads because I didn't get the bolt in far enough. Now I can't even thread anything on. I want to do this right and make sure I never have to deal with this nightmare again, so:
Would it be okay to just tap the same size and try a longer bolt? Or should I contact a machine shop to do it professionally?
What is the pricing for a machinist to come out and do this repair?
Thank you to anyone who sees and responds to this, I appreciate your help!
Remove the old bolt. Clean up the existing threads with a tap. Install using a threaded rod, then install new crank bolt and tighten to spec.
Instructor
Joined: Jul 2016
Posts: 128
Likes: 26
From: Oak Ridhe MIssouri
Muncie21 is giving you excellent advice. Go buy a tap. Yes I know they can be expensive. But it's nothing compared to having a bolt galled in the end of the crank. This is one of those deals that can get bad fast. Good luck. And take your time. Use lube.
Instructor
Joined: Feb 2020
Posts: 129
Likes: 26
This past weekend I attempted HB replacement as well as a cam install with a buddy. As I was away from the car taking a phone call, my buddy attempted to install the UD Harmonic balancer on his own. Once I got off the phone, he tells me the bolt won't back out 
My question is, is the crank repairable or am I screwed? I put the car back together as best as I could. I did the job due to a wobbling balancer and now is doing exactly the same thing just not as bad.
Thanks in advance
My question is, is the crank repairable or am I screwed? I put the car back together as best as I could. I did the job due to a wobbling balancer and now is doing exactly the same thing just not as bad.Thanks in advance
Instructor
Joined: Jul 2016
Posts: 128
Likes: 26
From: Oak Ridhe MIssouri
My first thought is the bolt bottomed out. Mashed the end threads and then galled as he tried to back it out. Or it was installed too dry and galled. If it won't back out then you're best to not try to remove it because it'll take the crank threads with it. And or twist off. This is mess I was referring to in an earlier post. My living involved cranks for years. I once spun a bolt in by hand and it galled. Had to machine it out on a mill. The right craftsman could prob drill it out and pick out the remaining threads. Gonna be a bitch because of where it is. Might be borderline quicker to pull off everything in the way so you have better access. Worst case you pull the engine. Even worse case yet you put in a crank. I feel your pain. The other possibility I can think of is the bolt had loktite on it. If that's all it is then you can heat the end of the bolt head and it'll break loose. Prob have to be hotter than you can get with a common propane torch. Best of luck be
