Future_Z_Owner

So i pulled my harmonic balancer hub because i wanted to see if my keyway was there (had a guy destroy my engine twice trying to rebuild it.) The second time he destroyed it a piece of metal that looked like a keyway got into one of my cylinders. Anyways so after spending over $4000 on this rebuild all together i was pretty much done with rebuilding the motor myself. I just wanted to be 100% sure i had my keyway in though. So i pulled the hub off and to my surprise the motor isnt even supposed to have one. Oh well i think at least i wont have it in the back of my mind anymore. So im re-installing the hub with the hub bolt (because the installer i got is completely useless.) Things where going great until the wrenching got pretty easy. I already knew right off the bat what happened. I back the bolt out and i have stripped my crank threads... 5 threads deep. Any suggestions on what to do? Can i tap this POS and use a bigger bolt?

94ltz

Wow man, sounds like a bad day right there... Which end of the threads did you ruin.. the ones that are on the out side toward the hub or in the inside toward the start of the crank.. if it the start ones you might be able to get a reverse tap in there and thread it out and save some you'll just have to be safer installing it next time if you can save it..

shoebox

Lesson learned. You never install a hub with the bolt. Anyone that has ever done and it worked is just lucky. You might be able to somehow clean up what you have and get it to work or you might have to drill an heli-coil or go bigger or worst case you might need a new crank.

Spartan7

I learned that the hard way too. Run a thread chaser through there (not a tap!) and see if you can clean it up some. I took it to a shop and had them take a look at it. I got lucky and mine just needed some cleaning up. But a good shop can helicoil the crank if need be.

This is the tool you should have used to install it:

http://members.***.net/gmarengo/Misc/Misc.htm

Future_Z_Owner

The only chasers i can find are for spark plugs. I really hope i can get this thing fixed. I cant afford to tear this thing down and put it back together again. Money wise or time wise.

meissen

Eh? Did they use an aftermarket crank? My LT1 has a key for the hub... Though maybe it's a difference between '94 and '95?


Though not the best way to install a hub, a sledge hammer and a 2x4 does work. But it's pretty backyard mechanic and you might break other things - use as last restort.

bw_hunter

The 94 and 95 both have keys in the crankshaft. It engages the timing gear and neds to be there. It doesn't engage the hub which is why the OP thought there wasn't one....

You didn't, seriously, whack the hub with a hammer and 2x4, did you? Either way, that's a pretty bad recommendation to give someone...especially when you can rent the proper tool for almost zero dinero.

matLT1

I would install a helicoil kit and call it a day. You can buy the helicoil kits at mom-and-pop autoparts stores for about $30-$50 and they are very easy to install. You could try to chase the threads or drill to a larger hole, but IMO either case may not work and you will only be performing steps that will be leading up to a helicoil. I'd just do it once and do it right. Buy the helicoil kit, carefully follow the instructions AND install the hub with the proper tool (no hammers either).

meissen

Yeah you're right. I was thinking of the hub but it was the timing gear. The hub just aligns the dot to the dot on the timing gear. Been a few months since I've been looking at that part of the engine.

And I sure have - it was actually a recommendation of a few people - a "Use at your own risk" recommendation, of course - in this forum back when I thought I screwed up my crank's threads just like the OP.

And the auto part stores by me don't have the correct puller/installer - only the SBC one which doesn't work with an LT1 because of the bolt sizes being different for the hub. Never saw that bolt setup posted earlier in this thread before - wish I had, seems a lot easier.

wrd1972

I just buy a piece of all thread form a shop with a pair of nuts and washers. Cut a 6" pice of all thread off, thread it in the crank and use some nuts to run the hub on. Works perfect and costs less that $2.

Future_Z_Owner

Kinda curious about this because i cannot find a 6 inch grade 8 bolt fully threaded. The amount of force needed to do this job is pretty high i think we can all agree. So my question is did you have any concerns about the tinsil strength on the all thread that you bought? I just have this horror story playing out in my mind where it breaks flush with the crank snout.

Dave1980

I wound up using non grade 8 and it worked fine. If its going on right, you shouldnt need grade 8. I also had a billet piece of steel that fits into hub with hole to line hub onto threaded rod. This starts the hub on straight, and prevents galling. I have sure learned from the school of hard knocks in past.

95Blackhawk

Yah, what I did but it's more like $5...don't give him too much hope.

Also, I found grade 8 allthread very hard to find and gave up. however, I would suggest grade 8 bolts and BTW, I have stripped bolts putting on the hub but overdid it when I got it to bottom out. Always best to use grease to cut down on friction

wrd1972

It was NON grage 8 all thread, nothing really special. Same with the nuts.
What I did was use two nuts to spread the stress across a wider area and used grease on the threads.

Done this many times. Goes on faster than I can chug a beer.
No worries.

ulakovic22

+1 for all thread 7/16x20 IIRC. You can put the hub in the oven as well and it will go on easier. I have boiled the hub for a while and then used a 2x4 and sledge to knock it on and then torqued the bolt, but it was on an assembly table, not in the car.