Ok guy/gals. Ive run into a problem that I can't seem fix. I've talked to some people in the industry and no one has any solid answers. Btw thanks for your time Travis! I bought a gm crate lsx454 straight for gm. Come with the harmonic balancer already installed. I then found a full used setup and bought it all (was told it had very low miles). That whole set up came with a harmonic balancer but I decided to run the one that came with the motor. So when I brought the car to the tuner for the first time and he was trying to do the crank relearn (revs the motor up to 4k) he says it threw the belt due to it not being in line. That the crank is sunk in 1/4". So I get the car back and take look..now I come to the conclusion it was one of two things. Either the crank is in too far causing it to throw the belt or when the motor torqued the belt touched the upper control arm on the drivers side and caused it to throw it.(which I plan to file down some more- has about 1/2-3/4" of clearance ATM.)


So being that I had the other harmonic balancer I decided to change it to the one that came with the assessories. Changed it out and here's a comparison.
One that came with the lsx454 motor on the left and one the left the one that I bought as a kit used.









So I swapped them out and figured the problem was solved. Go to start the car this past saturday and I can hear a repeatedly slapping. Go to the front of the motor to see the passenger tensioner slapping repeatedly and the belt going in and coming off the harmonic balancer is almost ribbing in a way like its trying to walk off but is not. But it does not throw the belt. On Sunday I start the car again.. This time no slapping of any kind and seems to be on just fine.. Started the car again later on Sunday same thing..totally fine. I'm lost on what to do..aside front buy a whole new front end setup. The only thing I can think now is to shave the mounting bracket that houses the alternator, power steering pump and drivers tensioner. I'm thinking shaving the back side a 1/4 " will help the problem...any one have any suggestions or input it would be greatly appreciated. Thanks Steven


One with the old harmonic balancer:

 

Do you have any side pics to show the alignment of the pullies?

James

 

What brackets are you running, they are don't look factory. I'm betting the problem is in the bracket not the balancer....

 

What they said. Pics would be very helpful, from both sides of the engine.

You also said, "passenger tensioner slapping repeatedly and the belt...". In addition to an alignment issue you may have an issue with the passenger tensioner.

 

Thanks for all the reply's. Here is the for sale add that I bought the whole set up from. From what I see and read it all stock gm parts.

"I have a C6 front drive which includes water pump,alternator,power steering pump,brackets,belt,power steering lines to hook up to 1969 camaro steering box.These parts have 1900 miles on them,I have a 1969 camaro with a new LS2 crate motor in it and I went with a Vintage Air Frontrunner.This front runner works great in a LS swap in an F body."

At the moment I do not have any side shots. When the last harmonic balancer was on and I put a staight edge on the power steering pulley and the tensioner on the driver side and the harmonic balancer was about 1/4" in. As for the braket being out of whack I thought about that. But for something that structural to be bent seem a bit off. It would had have to took a real beating and I would think would visually show some kind of damage. Either way Im going to pull that off tonight and probley shave the back of it down around a 1/8" -1/4" I was told an 1/8" of difference over 2' is fine. Any more suggestions on what to check/ look at? Thanks Guys!!

 

I wouldn't start modifying things yet. For anyone to truly give you an answer we need more information, like pictures from the side. Does everything else line up EXCEPT for the balancer or is the the p/s bracket that's the only one off?

 

Check the alignment of all ribbed pulleys. The PS pulley is press fit and can be pushed on too far or not far enough.

 

I will get some picture when I get to the car tonight and post them up. As far as I know everything else seems to line up. If I remeber correctly there are three on the pulleys that run off that bracket - (ps, alt, and driver tensioner) The water pump has no ribs so that can go either way and it does run true-no wobbles. The belt is more twords the back of that. Then there is the balancer and the drivers tensioner which I forget how that mounts. As I see it I have 2 options at this point. Get a 1/4" spacer for the crank or pull everything closer to the motor around 1/4"...could the crank snout be different from a c6 vette? shorter I guess?

I did take that off with a puller to hook up the power steering line. But I put it back on with a installer and I checked it twice to make sure it was all the way on. Which means I cant go back any more. If it was the other way then that might be the problem. I might rent the installer again and double check again..

 

As promised 3/16" is what I'm coming up with..




And here's on of the drivers tensioner..look a bit uneven to me..

 

Answered your "duplicate" post in Gen IV. These guys covered it well...

 

I'm having same problem. I haven't had a chance to diagnose but at last glance it looked like my ps pump was at a bit of an angle...most likely due to bracket or pulley not set evenly.

 

"I did take that off with a puller to hook up the power steering line. But I put it back on with a installer and I checked it twice to make sure it was all the way on. Which means I cant go back any more. If it was the other way then that might be the problem. I might rent the installer again and double check again.."

Been considerable discussion on this topic..
Someone mentioned that GM has a TSB about the location of the p/s pulley.
It has to be pressed FLUSH w/ the end of the shaft...If it's not, belt damage, and/or squeeking can/will occur.
BTDT....

 

I took a look at it last night just to check it again. The arm of the actually pulley is less than 1/8 away from the pump itself. I am almost possitive it can not go back any more. I did rent the installer again and will probley put it on tonight just to really check..

 

Ive been pulling my hair out trying to figure out what is the issue..Id be intrested when you dive in to see what you are coming up with. Thanks Steven

 

The offset of the pulley grooves from the edge is not always consistant between the pulleys. Without a lazer alignment tool, put a strait edge along the front of the crank pulley. Measure from the strat edge to one of the crank pulley groves or ridges. Keep the strait edge on the crank pulley and measure from the strait edge to the same groove/ridge on the alt/PS/tensioner pulleys.

 

+1

You need to measure from the straight edge to a groove or ridge. I clamped an aluminum saw guide so it laid flat on the face of the crank pulley then kind of spun it to measure the distance from it to the first pulley groove on both the crank and accessory pulleys.

Since your crank pulley is recessed the straight edge will need to be to the side of the accessory pulleys. Gonna be tough while it is in the car. But from the looks of things the crank pulley is pressed too far onto the crank.

Truck, vette and F body belt spacings are all 20 mm apart (about 3/4 inch), so the problem isn't mismatched accessories.

 

Check and see if you don't have the idler pulley on backwards. The cup washer under the bolt looks wrong, it should be inset....not sticking out like it is...

T,

 

X2 on idler around the wrong way also try straight edge from alternator pulley accross p/steer pulley to harmonic balancer (disguard idler). also check outer on harmonic balancer has not come away for inner section ??? cheers