420A Belt snaps off on high rpms

[2g420aeclipse]

Apparently I've been having some belt issues every time I burn out or when I'm first gear and when I hit 6-7 rpm the belt slips off. I already replace the pulley and it has a new belt. Why does slip off? Is it bad alignment? Or what is it?

 

[ThunderChild]

which belt are you referring too?

 

[dsmcrzy]

My guess would be the ac/ power steering belt since the alternator belt doesn't have an idler pulley.... But maybe he does mean the pulley on the PS/AC/alternator. Or maybe even the crank pulley

 

[2g420aeclipse]

The serpentine belt

 

[ThunderChild]

There are two on the 420a IIRC. I suspect misalignment of the alt, p/s pump or possibly a bad bearing on the a/c pump. Also check the tensioners to make sure they stay tight and aren't backing off.

The crank pulley might have separated and under high load is misaligning slightly and throwing the belt off.

 

[chiefvest]

Do any of the pulleys seem stiff or crooked?