LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Don't know what to think. Please Help!!

Old Jan 31, 2008 | 03:18 PM
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Default Don't know what to think. Please Help!!

1997 Trans Am

Got in my car today and noticed that my power steering was not working. I immediately pulled back into my driveway, and popped the hood open. First thing i saw was my belt was not spinning and I figured one of the accessory pullies must have locked up, but instead by crank/harmonic pulley is not spinning at all. Forgive my lack of knowledge on this, but I have no idea whats wrong. Staying in park the engine runs/sounds just fine, but the crank pulley is not spinning. Any idea as to what is wrong???
Thanks in advance for any advice,
Dan
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Old Jan 31, 2008 | 04:35 PM
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update:

I'm pretty sure the water pump runs off the timing chain, so to see if the timing chain was the problem, i let the engine run for 10-15 minutes and the water pump seems to be working (the engine didn't overheat). Afterwards, I look underneath the car to see if the crank/harmonic balancer was still not turning. No!! The whole damn crank pulley+hub piece is laying on the ground, with the belt hanging from the engine.

My opti-spark was replaced at a mechanic shop last July. If they screwed something up then, is it possible the car still just ran fine for 6 months and 5,000 miles??? until finally the crankshaft hub just wiggled loose and fell off??
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Old Jan 31, 2008 | 05:05 PM
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thw water pump runs off the cam gear. it's possible that a bolt wasn't tightened correctly, or may have been cross-threaded (resulting in a lose fit). that may cause it to just fall off. i know i've heard stories like this from other people, as well.

EDIT: either that or your car is SOOOO damn powerful that it's ripping itself apart from the inside and unleashing it's full power! haha good luck

Last edited by sdm1234; Jan 31, 2008 at 05:12 PM.
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Old Jan 31, 2008 | 06:00 PM
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cool. I never heard of this happening to anyone else's car before. Thanks for the reply
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Old Jan 31, 2008 | 06:36 PM
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Originally Posted by palm0913
update: I'm pretty sure the water pump runs off the timing chain, so to see if the timing chain was the problem, i let the engine run for 10-15 minutes and the water pump seems to be working (the engine didn't overheat). Afterwards, I look underneath the car to see if the crank/harmonic balancer was still not turning. No!! The whole damn crank pulley+hub piece is laying on the ground, with the belt hanging from the engine.

My opti-spark was replaced at a mechanic shop last July. If they screwed something up then, is it possible the car still just ran fine for 6 months and 5,000 miles??? until finally the crankshaft hub just wiggled loose and fell off??
Yes, the water pump runs off a splined shaft and its gear end meshes with the cam gear, so does not require the serpentine belt.

There are three bolts that hold on the balancer/pulley unit. It's hard to imagine that all three bolts worked their way loose. However, if 1 or 2 worked their way loose, then the vibration would certainly work the others loose or to break off. Whoever worked on this should have used Loctite on the bolts and [obviously] torqued the bolts.

Do you see the hub? Is it still there? It slides on the crankshaft snout - it's a round piece of iron with three "ears" on it where the balancer/pulley bolts to.
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Old Jan 31, 2008 | 07:50 PM
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Originally Posted by caldercay
Yes, the water pump runs off a splined shaft and its gear end meshes with the cam gear, so does not require the serpentine belt.

There are three bolts that hold on the balancer/pulley unit. It's hard to imagine that all three bolts worked their way loose. However, if 1 or 2 worked their way loose, then the vibration would certainly work the others loose or to break off. Whoever worked on this should have used Loctite on the bolts and [obviously] torqued the bolts.

Do you see the hub? Is it still there? It slides on the crankshaft snout - it's a round piece of iron with three "ears" on it where the balancer/pulley bolts to.

The hub came off with the pulley. The pulley and hub are still attached to each other, and they fell off the engine in one piece. I'm guessing the last person who put the hub and pulley back on my car forgot to put the hub bolt on. Probably slid the hub on the crankshaft (which fits tightly), forgot to secure it by screwing in the bolt, then attached the pulley to the unsecured hub (with the 3 bolts). So, it was only a matter of time before the hub worked its way off the crankshaft.

Does this seem about right?
Needless to say, I don't wanna bring my car back to their shop unless I have to. Will having a loose hub/pulley like that give me problems further down the line that aren't showing up now?
Can I just go buy the hub bolt and put it back on correctly myself, or does this kind of job call for special tools or proper balancing?

thanks again guys
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Old Jan 31, 2008 | 08:51 PM
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Originally Posted by palm0913
The hub came off with the pulley.
[snipped]

Needless to say, I don't wanna bring my car back to their shop unless I have to. Will having a loose hub/pulley like that give me problems further down the line that aren't showing up now?
Can I just go buy the hub bolt and put it back on correctly myself, or does this kind of job call for special tools or proper balancing?
I'd say you'll be fine with buying a new hub bolt and re-install the hub, then re-install the balancer/pulley. There are no special tools required, but if it were me, I'd mic the outside diameter of the crank snout and then the inside diameter of the hub to be sure the I.D. didnt wallow out. Also, be sure when you install the hub, that you use the alignment (arrow) marks (engine at TDC) - there's one on the hub and one on the timing chain rib cover (the crank snout/hub are not keyed).
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