Sc400 Crankshaft Bolt Won't Go In

[xhimsa12x]

Okay guys, the sc was overheating so I narrowed it down to the water pump. Took off the water pump and found that the propeller wouldn't even spin anymore. Was totally froze up. Okay got the new pump on and as you all know, it's a freaking chore to take all the crap off just to get to the water pump. I am trying to assemble this back. I have the crankshaft pulley seated and the bolt won't thread. I can get it in to about the first 3-4 threads and then it stops. I think I screwed up big time. First I thought it was the bolt so I ordered a new one from toyota, just got it yesterday, tried to crank this one down and nothing. same exact probelm. So I have ruled out for sure that it's not the bolt threads that are messed up, it's inside the crankshaft opening. How in the hell do I fix this?? I gotta get this thing back togather by sunday evening or I won't have a ride for work or school. I believe I messed the threads up when I was using the harmonic balancer to remove the pulley. I forgot to put the cone tip on the end of it and I threaded that bolt in a couple of threads. It wouldn't go far at all so I finally figured out I had to seat the cone on the end of the middle bolt. I feel like a complete !Removed! and my car has been down for about 3 weeks now. So how can I fix these internal threads?? any other ideas?? Thanks guys!

[SRK]

You've got a problem alright. You've damaged the internal threads, and you'll have to work carefully to restore them.

Take the bolt to an industrial supply or machine tool store. They can sell you a "tap" that is designed to cut the same thread form as the bolt. Buy what's called a "taper tap" - the initial threads on it are not fully formed, which will allow you to engage the threads in the crank gradually, and then re-cut the ones you've damaged or rounded over. What is very important is that you don't begin cutting threads on top of the existing ones - you must synchronize the tap with the existing ones. If the tap is successful you can then re-install your new bolt and all is well. There should be plenty of thread engagement on the bolt even with a few "cleaned up" threads in the crank.

If you are not familiar with taps and their use find someone who is. You might be able to find a "thread chaser" in the correct metric thread matching the bolt.

You have one chance to fix it - otherwise it may be time to change the crankshaft...

[1JZPWRD]

exaclty what he said.. Be darn careful and make sure it is straight when you get it started. ^^^^^^^^^