The harmonic balancer on my 99 came loose at the track today. It moved out enough to throw the belts. I was able to bolt it back down and get it to align correctly and make the 60 mile ride back home.

I see from various posts that the bolt is a single use item and it’s a good idea to replace the balancer also.

How much of a job is this? This can be done with the engine still in the car, right?

Any hints, ..tips etc ??

Thank you!

 

You most definitely leave the engine in the car. Here's a link on ls1tech that gives directions for a heads/cam swap. You can skip a lot of the steps that aren't directly related to getting to the balancer. You don't have to remove the radiator if you're not putting in a cam. Removing the steering rack is the hardest part. I believe the ls1tech site shows using the old balancer bolt to press the new one on. You should probably not do this, and instead use the homemade tool that screws into the crankshaft. Do some searching if you don't know what I"m talking about. Overall, it's a big job, but lots of us have done it.

http://www.ls1howto.com/index.php?article=1

 

Yes, definitely replace the bolt! While you have the balancer off, you are only a few bolts away from a cam swap! Do yourself a huge favor and get an underdrive pulley like the Powerbond (thats what I have on my stroker) and purchase an ARP bolt rather than a GM replacement. Be aware that the torque specs are totally different on the ARP piece and it is way easier to install. Also, be sure to look on LS1 tech and buy a balancer installation tool, do NOT use an old bolt to pull it on! This article covers balancer removal and replacement.

http://ls1howto.com/index.php?article=1

 

How did you bolt it back down? Usually there isn't enough room between it and the rack to get a socket and rachet in there.

It can be done still in the car, but you will have to get the steering rack out of the way. It also helps to remove the fans so you will have room for the puller.

The bolt that holds it on is a "torque to yield" bolt, meaning it stretches when you torque it to spec. The are only about $5 at the dealer. There are some aftermarket ones that can be re-used.

If you have a manual transmission, the balancer is supposed to be marked before removal and put back in the same position.

Since you already have it back on there and it made the trip home, you should be able to just do the installation procedure.




Installation procedure:

-if the balancer is not already on, it may help to heat it to about 150* or so, just prior to installing it. Some people put it in the oven, some put it in boiling water. When I did mine, I didn't heat it at all.

-once balancer is on the crank and as straight as possible, install the old bolt.

-tighten the old bolt to 240 ft lbs to seat the balancer.

-to check if it is seated properly, the end of the crank should be recessed in the balancer .094 - .176 inches (or 2.40 - 4.48 mm)

-once seated, install the new bolt and torque to 37 ft lbs.

-then, using a torque angle meter, tighten the bolt 140*. You can buy a cheap angle meter at any auto parts store for about $10.

-you're done.

 

Thank you guys for fast and great responses!

I was able to use a 15/16ths open end wrench in between the steering rack and the bolt head and turn the bolt 1 nut flat at a time, took about 25 minutes to get the balancer back to where it lined up with the other pullys.

I kept the revs under 2000 for the ride home, no oil leakage (some did spray out at the track duribng that last pass) - the bolt only seemed slighty tight when I arrived home.

 

In the process of doing this job right now. I removed the steering rack, hoses ,and fans to get the old balancer off. Mine broke by the belt pulley flange separating from the balancer hub. Bought a 300mm 16x2.0 piece of threaded rod from McMaster-Carr an some nuts and flat washers from Home Depot to press the new balancer on straight. Cost about $16 to make this up. Got a Powerbond balancer direct replacement from O'Reilly's Auto. Bought new bolt from GM for $6.

Where can I get this ARP bolt from? Sounds like it is a better setup.
Doing some other work on the car so I can replace the bolt now if I can get it within a week.

 

If you are using the GM bolt (torque to yield) you will need to remove the exhaust pipe, starter and bolt down the flywheel to get the 140 deg after it reaches 37 ft=lb. With an aftermarket bolt they suggest 240 ft-lbs. In either case I would add extra locktite because if you run a lot of HPDE's it will probably come lose again.

Using the torque to yield method I could not keep the engine from turning without removing the starter.

 

If you have a manual trans, all you have to do is put it in gear and put the e-brake on.

This is what I did with an automatic. It just takes a few seconds to wrap it up.

http://forums.corvetteforum.com/show...881&highlight=

 

With a manual trans, we could not keep the engine from turning by using the brake and gear. At about 120 degrees it started to move the engine on the motor mounts and then the engine would start turning.

 

I changed mine yesterday, it was comming apart! what a pain! Today I noticed a louder than normal ticking (like injectors) & what sounds like a fan blower inside while driving. To make things worse the clutch pedal feels strange, like it is on the floor after driving at very high revs and speed. I'm switching intakes & t-body tomorrow some I can have the car tuned, so if anyone has any ideas I thank you.