Off track serpentine belt

[Tynan918]

This is the second time my belt has jumped a rib on the crankshaft pulley...

First time I noticed, it was the last belt I had on it, the belt stripped from the same side...

I just replaced the 8" balancer with a 6.75" balancer, and a friend told me maybe because of the different height size balancers, would mean different depth sizes but after measuring the depth on both balancers, they are the same...

...so balancer is crossed out from the list of possible causes.

He said the another possibility he can think of is the crankshaft pulley being wrong depth size, causing the belt to jump a rib...are there different SBC crankshaft pulley sizes between cars and trucks ?

What do you guys think ?

 

[ELCAM]

Should be 3" from the block to the face of the balancer.

 

[Tynan918]

Should be 3" from the block to the face of the balancer.

View attachment 194532

Good reference ! I'll go out and measure that !

 

[ostrich]

Good reference ! I'll go out and measure that !

From your pics the crank pulley is out farther than the ps pulley, the ps, water pump and alternator pulleys are in line with each other? The back on the belt rides on the tensioner so it won't make the belt skip a groove. Take your harmonic balance measurement, I think it will be over 3"

 

[bruisedbanana79]

Well you are measuring the balancer to block take a really good look at the crank pulley itself, I know on my stock pulley it has a protrusion that centers the pulley in the balancer. Just make sure the mounting surface it flush with the balancer

 

[Tynan918]

Well you are measuring the balancer to block take a really good look at the crank pulley itself, I know on my stock pulley it has a protrusion that centers the pulley in the balancer. Just make sure the mounting surface it flush with the balancer

Ok, I'll take a picture.

 

[08Malibu]

How did you use a balancer installation tool if your crank snout won’t hold a bolt? The tool I own uses those threads to hold the installation tool.

 

[Tynan918]

How did you use a balancer installation tool if your crank snout won’t hold a bolt? The tool I own uses those threads to hold the installation tool.

I honestly don't know...thats what I'm trying to figure out...the tool worked but no bolt.

Here is a picture of the backside of the balancer/front side of the timing cover... You can see some balancer shaft, is that normal ?

 

[79 USA 1]

Just a quick question, When you installed your lower timing gear onto the crank did you tap it back until it seated against the journal on the crank? Looking back at a previous thread where the discussion was about removing a broken fastener, the lower gear does not appear seated. This could be the issue that while the balancer is bottomed to the crank gear, the crank gear is not filly seated on the crank.
Your Picture shows very little if any of the key exposed.

This is a photo from Cloyes web site.

 

[Tynan918]

Just a quick question, When you installed your lower timing gear onto the crank did you tap it back until it seated against the journal on the crank? Looking back at a previous thread where the discussion was about removing a broken fastener, the lower gear does not appear seated. This could be the issue that while the balancer is bottomed to the crank gear, the crank gear is not filly seated on the crank.
Your Picture shows very little if any of the key exposed.
View attachment 194578
This is a photo from Cloyes web site.
View attachment 194579

I used the balancer install tool to press the crankshaft gear...

This is as far as I pressed it to the block...I posted in that thread and asked if this was pressed far enough...you can see some key way sticking out...

I greased it and the shaft before pressing it on... I tapped on it real good with a pin and 3 lb mini sledge hammer.

 

[Tynan918]

Should be 3" from the block to the face of the balancer.

View attachment 194532

From your pics the crank pulley is out farther than the ps pulley, the ps, water pump and alternator pulleys are in line with each other? The back on the belt rides on the tensioner so it won't make the belt skip a groove. Take your harmonic balance measurement, I think it will be over 3"

Well because of the serpentine belt brackets attached to the engine, I can't measure from the engine block to balancer...

What's the distance from the oil pan to the balancer ? I can measure that...