Belt Splitting...hopping grooves..??????

91 Laredo 4.0 Auto. 196,xxx miles.

Pulled into a parking lot and heard part of the belt flapping around. the belt hopped a "groove" towards the engine (not fans) and was pinched on something really close to the crank shaft pulley and cut the belt.

Got new belt put it on and it happened again within 30 seconds. Killed the engine and put the belt back on and it didnt happen for about a week...and my belt is ruined again.


I have no idea why it is hopping...please help...got any ideas?

Your crankshaft pulley is toast.
There's an inner and outer part of the pulley - held together by a piece of rubber.
The rubber gets old and breaks apart.
Sometimes the outer pulley slides forwards, and sometimes, as in your case, it slides towards the engine.
* Watch out for a groove worn into the timing case cover.
===
By the way, to tell if this is the problem or not, look at the inner and outer parts of the pulley.
They should be flush with each other.
You're going to probably see the outer pulley closer to the timing case cover than the inner pulley.
===
Have fun with that one! :thumbup:

thanks ill check it out tomorrow. If theres anything else that could help me out...i havnt taken one apart yet thanks

I've seen more problems with a loose bolt on the alternator or power steering pump that allows them to get out of parallel.

Concur - check to see which pully is out of line. Typically, it's the crank pully.

You can check it with a straightedge laid across the face of the thing. The whole pully is changed as a unit - and a new pully can be had for around $50-60. Change the crankshaft seal while you're there - it takes an extra five minutes and costs $5-8. Cheap peace of mind - search here, because the job has been covered in some detail a few times. Try "harmonic damper" or "harmonic balancer" for search strings.

thanks guys, once i new it was called a harmonic balancer i found a ton of helpful threads. The rubber ring is deffinately showing...


thanks again