LVZ2881

iTrader: (4)

It appears that when reinstalling my crank hub tonight, I stripped the threads out of the crank, as the balancer bolt will not tighten. I pulled the bolt back out and there were metal "rings" (you all know what a stripped thread looks like) on the bolt. I freely admit that this is my first time reinstalling an LT1 crank hub, and apparently did not know when the hub was fully seated, thus, making myself an idiot.

What are my options??

I'm going to first try and retap it, and if that doesnt work, my next guess is to helicoil it. Luckily the motor is out and on a stand.

jlpz

iTrader: (8)

Helicoil is the best way to fix it..I don't think retaping it will work if the threads are really messed up..

93 LT1 Vette

I'd say your options are a new 3.48 stroke or 3.75 stroker crank. Helicoil, JB weld or loctite will not be an option at 5500 or 6000 rpms on a moving mass. It is a critical TQ that must be achieved. I've lived the after effects of a harmonic balancer departing a fresh 383 at 5500 because the snout bolt was not installed. It vibrated so bad that I couldn't see out the windshield of the car and ripped the hoses off the frontend of motor and broke the water pump in two. The rod and main bearings were flat spotted not to mention the guy driving was head long into the pedal at 105 mph when it came unglued.

Sorry but thats what I'd do.

henry172

iTrader: (2)

Helicoil is working fine on my crank

moehorsepower

iTrader: (3)

This happened to me once, I measured the length of the bolt then the depth of the crank snout, In my case there was quite a bit of good threads left inside the crank, I took measurements, and got a longer bolt making sure it did not bottom out in the crank, and to my surprise, it worked, took the full torque requirements with no problems..But as said a helicoil will work and actually is stronger than the threads.

RamAir95TA

iTrader: (2)

There is nothing wrong with a heli coil in the crank.

But I would prefer a Timesert instead.

Shame on people who would rather spend $1000+ on a rebuild, just to fix one screwed up bolt hole.

shbox

You use a torque wrench to tighten the bolt to 74 lb. ft. and you never use the bolt to pull the hub on. A helicoil or insert should work and be thankful you have the engine out to have room to do it.

moehorsepower

iTrader: (3)

He is correct, How many times have I seen and I hate to admit back in the day I did it too, where people try to install the hub by trying to press it on with the crank bolt, there is a special tool for installing the hub...

quik95lt1

iTrader: (7)

yep a helicoil will work just fine.........nothing wrong with it......the threads on the bolt will still achieve their stretch

96TransAmboosted

iTrader: (8)

I agree with the timersert much stronger and better. Sometimes hard to find but worth it in the end.

I would try and chace the threads clean them out good and see what your working with. You may get luck and have enough to re tap and install correctly.

Ls2SilverBullet

I know what a helicoil is but what is a timersert?

fex77k

iTrader: (2)

RamAir95TA

iTrader: (2)

http://lmgtfy.com/?q=Timesert

LVZ2881

iTrader: (4)

Also, just FYI, I was installing the hub with a 3'ft peice of 7/16 x20 all thread, washers and nuts. guess I went too far.

EDIT: That timesert stuff looks interesting. Never heard of it before now.

shbox

Or maybe you were just unlucky or the threads had some previously unknown damage. Again, since you have good access, there should be no problem in taking care of it.

96TransAmboosted

iTrader: (8)

Timesert is a much stronger type of helli coil. We use these at the dealership and there worth the extra money. The strength is 2nd to none and in over 12 years I have never had one fail. Smetimes you van even fetal them if needed.

shbox

If you read that fast, it sounds German. Tell me, what does it mean?

96TransAmboosted

iTrader: (8)

lol i guess i should proof read when using my phone,

I was trying to say that the timesert is so strong that you can even chase them down the road if needed.

97LT1

iTrader: (3)

Here is what I used on my crank hub after having some trouble. It is basically a threaded rod that you screw into crank, then tighten the nut that presses the metal slug into crank hub opening. This presses the hub on the right way. I bet a machine shop can make you one of these.

I was having major issues getting hub on even with this tool, until i realized that the aftermarket hub was not machined correctly and was too small. I was sweating bullets, because i was almost messing up my brand new forged crank.