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SBC 350 Harmonic Balancer/Pulley wobbles.. VIDEOS INSIDE

12K views 23 replies 7 participants last post by  Sin7 
#1 · (Edited by Moderator)
I finally got my dual Flowmaster 40 series installed and now I can see and hear something that I couldn't before.... Let me rephrase.... The exhaust installation isn't what caused this. Just meant to say that now that I dont have open headers I can hear what the engine is doing and pinpoint noises a little better...

I notice that my lower pulley is wobbling and making an "off balance" rattle. Could it be the pulley or the harmonic balancer?

Take a look for yourself....

First video

second video
 
#3 ·
Pulleys

What ebay seller did you buy these from? I know some folks that also bought chrome pulleys that should be made aware of this. There are some pics on the web of import chrome pulleys that have come apart and caused a lot of damage,I would forward that video to the seller and ask them to warranty the product or refund it.
 
#8 · (Edited)
The good news is that I was able to find the problem. As I was taking the lower outer pully off, one of the 3 bolts that hold it in place just slipped right out. So it's stripped..



That one bolt is what made the entire lower section wrattle. here's a vid with only the inner pulley spinning...

http://www.youtube.com/watch?v=r7jhomDkmC8

Doesn't vibrate at all...

Also swapped the water pump pulley with the stock one.
 
#9 ·
I have the stock one piece lower pulley assembly, so can i just put that one one as a temporary fix just using the center bolt to hold it in place? Or do I need to have the other 3 bolts also???...


Also, can I just use a tap set to rethread that one bolt?
 
#12 · (Edited)
yup, they're 3/8" fine thread. I walked to autozone and they had a bunch of helicoils but he said i needed the 3/8-20 and they didnt carry that. Told me to go to NAPA. I thought since the bolt is already a 3/8 i would need to bump it up in size??

The 3/8 fine bolt just slips right in and out of the current hole. So there's no threads at all...

You answered my other question: Is it necessary to take the balancer off to do this.

When my wife gets home I'll drive to NAPA....
 
#13 ·
Jmark said:
You will actually drill it oversize even more, then use the special tap (it's not a standard size!) to make the threads for the helicoil insert. When it's done, it will be back to 3/8"-20.

Just make sure you don't let it grab and drill into the timing cover!!! LOL Mark the depth on the bit with a small gas line clamp to keep the bit from shooting through.
gotcha...

Thx for the gas line clamp tip. I usually use tape but it tends to slip.
 
#16 ·
Jmark said:
You can get specific size packs at almost any auto parts store. I believe those are 3/8" fine thread? (don't hold me to that! LOL) You will get a drill bit, special tap and about a half dozen inserts. Very simple to do, even in the car. Used them myself the first time on a bunch of stripped holes in my TH350 tans valvebody.
Since you are here in Phoenix the nut and bolt store across the street from The Chrome Guy on 67th ave 1 blk south of Northern sells them seperately.
 
#17 ·
ONCE AGAIN I'D LIKE TO THANK YOU GUYS FOR YOUR HELP...

I picked up a helicoil kit from NAPA and fixed that stripped thread. I must admit that it wasn't until yesterday that I had ever heard of a Helicoil. I was worried i wasn't going to be able to do it myself. But just like every other thing i've done to my car, i'm proud to say i did it myself.

Here are some pics. Most of you could care less to see these, but i'm posting them up for the next person who runs across this. Hopefully they'll be useful to them...



After drilling the hole I tapped it.


Carefull not to go to far:




insert the coil...


New threads.


Good as new:
 
#21 ·
Jmark said:
Wanna take a guess why I needed to come up with that one? LOL :drunk:


BTW....what kind of camera were you using? Very good pictures for such close quarters. I just got a Canon S5 IS and still learning.
its a Nikon Coolpix S5.....

My wife locks up my Nikon D40 when i'm working on the car....
 
#22 ·
heli colis.....

HI,on the bottom of the heli coil theres a little *** that goes across,after you drill,tap, and put in the heli-coil,you have to take a small punch and break this *** off (from the inside) if you dont,the heli coil will work its way back out. breaking the *** off,locks it into place.
 
#23 ·
boatbob2 said:
HI,on the bottom of the heli coil theres a little *** that goes across,after you drill,tap, and put in the heli-coil,you have to take a small punch and break this *** off (from the inside) if you dont,the heli coil will work its way back out. breaking the *** off,locks it into place.
uh oh, i didnt break the tang off... :eek:
 
#24 ·
Jmark said:
You might want to pull the bolt and break off the tang. But, i've left them on before and haven't had a problem, but I use locktite on them too.
I'm gonna leave it on there for now but i'm going to keep a close eye on it. I took the car for a drive around the neighborhood and everything was tight. None of the pulley's wobbled or screeched
 
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