Belt squeal at full throttle

['05_Z71]

Hey,

 

I got a full throttle belt squeal that happens only when the truck shifts from 1st to 2nd gear. Anyone had this problem before or know a good way to identify which pulley is causing the problem? Also seem to get excessive knocking from time to time too but that seems quasi normal for these engines.

 

Thanks in advance.

[Bish]

Hey,

 

I got a full throttle belt squeal that happens only when the truck shifts from 1st to 2nd gear.  Anyone had this problem before or know a good way to identify which pulley is causing the problem?  Also seem to get excessive knocking from time to time too but that seems quasi normal for these engines.

 

Thanks in advance.

 

<{POST_SNAPBACK}>

 

 

 

Belt squeal is normally seen in the 1-2 shift after a shift kit is installed. It's caused by the accessories overspinning when the engine shifts to and the rpms drop quickly. Mine does it ever since the built trans went in. Some had had luck with gatorback belts and other suggest belt dressing. I've never liked using belt dressing as it tends to gum things up. Some have also had success cleaning all the pulleys and using a new belt.

 

I just live with it.

 

Regarding the knocking, never is knocking a good thing. I used to get knock when I was running a Hypertech Programmer but none since going with a tune. I do get some knocking when the intake and top end start to build up carbon deposits. When I do a top engine cleaning (including spraying it into each spark plug hole and sitting overnight) it usially eliminates any knock or ping until the next 30K or so when it needs cleaning again.

['05_Z71]

Hey,

 

I got a full throttle belt squeal that happens only when the truck shifts from 1st to 2nd gear.  Anyone had this problem before or know a good way to identify which pulley is causing the problem?  Also seem to get excessive knocking from time to time too but that seems quasi normal for these engines.

 

Thanks in advance.

 

<{POST_SNAPBACK}>

 

 

 

Belt squeal is normally seen in the 1-2 shift after a shift kit is installed. It's caused by the accessories overspinning when the engine shifts to and the rpms drop quickly. Mine does it ever since the built trans went in. Some had had luck with gatorback belts and other suggest belt dressing. I've never liked using belt dressing as it tends to gum things up. Some have also had success cleaning all the pulleys and using a new belt.

 

I just live with it.

 

Regarding the knocking, never is knocking a good thing. I used to get knock when I was running a Hypertech Programmer but none since going with a tune. I do get some knocking when the intake and top end start to build up carbon deposits. When I do a top engine cleaning (including spraying it into each spark plug hole and sitting overnight) it usially eliminates any knock or ping until the next 30K or so when it needs cleaning again.

 

<{POST_SNAPBACK}>

 

 

 

 

Drivetrain wise, my truck is bone stock so I'll just chalk up my issues to GM.

[vhato]

I was driving my fiance's '05 Crew Cab the other day and noticed the same things.

 

I can hear exessive knocking when runnin 87 octane fuel and at WOT just as it shifts into 2nd gear I hear belt squeal.

 

I assumed the knocking was from the Vortec 5300's *more* agressive timing advance tables, but the belt squeal really bothered me.