How do you fix a stripped harmonic balancer bolt? I'm not sure how this happened, but after I pulled the bolt out after getting the hub most of the way off the threads were stripped about 1/2 an inch worth on the end of the bolt. I tried screwing it back in but it doesn't want to go really. I can try forcing it but I'm not sure that's the right answer.

I tried putting a clean new crank bolt in it but it doesn't want to go. I've got the engine on the stand right now. Please tell me there's an easy way to fix this. I was planning on working this whole weekend on the car and I'm stuck if this doesnt' work. Please help

 

Don't EVEN try to use the damaged bolt. I know...too late. Try to chase the threads with a tap. If that isn't successful, you'll have to drill it out, and tap it for a 1/2" thread, and use a big block bolt.

RACE ON!!!

 

Is this your crank your talking about? Do you have access to a good quality tool and die set? If not, stop right there and match up the bolt threads with a high quality tap. Re-tap the hole carefully and your back in business. If it is REAL bad you could put a heli-coil in it..but, I dunno about the crank. You might want to call a machinist if it is real bad Good luck

 

Try running a tap through to clean up the threads and see if a clean bolt threads in. If it has enough threads left to hold, use some locktite (permanent type). If it is still a problem you can use a Heli-coil to replace the threads. They work really well if installed correctly.

 

my god, i thought i was the only person on earth who has had this happen to them...

I almost had a stroke when it happened to me... Cleaned the threads and a new bolt, and it seems to be working fine...

 

Well guys, total cost of this screw up $10.81. I took it to a machine shop and told the guy what I did and he said we'll just retap it to a half inch or helicoil it. And they were out of helicoils so we upped it to a 1/2" bolt. The bolt cost me $0.81 and the guy charged me $5 to do it and I gave him a $5 tip.

I also made myself a little tool that will prevent this in the future. I took a bolt smaller than the diameter of the whole and about 6" long and this bolt will go all the way back to the back of the crank and not push against the threads. It was a little fun making the round top of the bolt flat, but you gotta love cutoff drop saws.

Now all I have to do is check the washer inner diameter. It may have to be "adjusted" to fit the new bolt. I'm pretty sure the hub has enough clearance though.

But it's all a learning experience, atleast this one was cheap to fix but enough of a pain in the butt that I'll remember from now on.

 

 

Been there, done that. Stripped one on a 305 once; had to pull the radiator and all kinds of stuff to get at it. Heli-coil saved me ****.

 

I'm glad you got it fixed. And so reasonably, too. I'm not sure I understand what you are explaining in what I quoted, above. Is that to pull the damper? I bought a puller at one of the parts chain stores for under $15.00. It has a "vee" that fits over the end of the forcing screw, so the threads of the crank never get involved in the pulling operation. That store (and most others) "rent" a puller, for free. I have made my own installer.

RACE ON!!!

 

Well, I have a puller that I used but you are supose to pull out the bolt, remove the washer, then put the bolt back in a few turns and the puller pushes off of that. Which causes stress on the threads in the crank and on the bolt.

When putting it back on then it I use the "vee" attachment that pushes on the balancer itself and I usually push off against the crossmember of the car. Doing this with the engine out I purchased a bolt that was about an inch longer than the normal bolt and tightened this on. The exta inch is there to get more thread grip while the balancer is sticking out so far. I did it 4 times, one with the long bolt, then the long bolt with the washer, one with the normal bolt and then one with the normal bolt and the washer.

Oh and by the way, you do need to drill out the balancer as well to get the 1/2" bolt to fit.

 

I can see how the threads got screwed up. The "vee" that slips over the end of my forcing screw has an OD of about 3/4"-1". The "vee" part is a 45* angled cone that matches the chamfer in the crank bolt hole. Therefore neither the damper bolt nor the threads in the crank come into play during the pulling process.

For an installing tool, I bought an extra long bolt. I used a truck spring center bolt. They are available in different lengths. I also bought a spring, u bolt "hi nut", two small flat Torrington bearings and three hefty flat washers to act as bearing races. First, I get the damper into position. I screw the nut, all the way onto the spring bolt. Then, I load a flat washer, a Torrington bearing, another flat washer, another Torrington bearing, the third flat washer, and finally the stock damper washer, onto the spring bolt, in that order. I applied wheel bearing grease to the Torrington bearings and threaded the spring bolt all the way into the crank, until the bolt bottomed. With the spring bolt bottomed, I am engaging ALL of the crank threads. Then I tighten the "hi nut", and it forces the damper into place. The Torrington bearings prevent excessive friction with a tight damper. You could use your "vee" instead of the stock damper washer. Just make sure your "vee" doesn't contact the end of the crank, before the damper is all the way on. This "tool" works on the engine stand OR in the chassis. Huh? I don't understand THAT, at all.

RACE ON!!!