Holy cow..main crank shaft pully loose on my 4.0 engine

[bradleyheathhays]

The 4.0 inline 6 engine in my '96 Cherokee has 188 k miles on it and (I thought) the serpentine belt or something close by has been squeaking badly for a month now. Tried all kinds of idler pulley tension adjustments and the squeaking continued. I go to start it today and the serp belt jumps right off. Turn the engine off, open the hood to find the belts off. I rotate the main belt driven cooling fan and the blades now nick the main crank case pulley. Started moving the main crank pulley and sure enough it tilts up and down a bit with hand movement and since it's hitting the fan blade I guess it's loosened up enough where it's migrated forward, away from the engine some.

I have zero experience dealing with this pulley but since there's plenty of clearance hopefully I can do what it takes to get it fixed.

Anybody have an idea of what's gone wrong or what part I need to replace?

[JPNinPA]

Pic of the pulley ??
Is it salvageable or is it bent or nicked where it will ware or jump the belt?


Never look down on anyone unless you are helping them up - Jesse Jackson

[bradleyheathhays]

Looks like it's called the harmonic balancer. I've seen where the inner and outer wheel can become disconnected causing my problem so at my mileage I'm gonna go ahead and replace the thing. Just found some videos that make it look fairly straight forward. Only thing is none of them went so far as to replace the main front seal. Is there a problem with replacing that seal? I'd like to get mine done while I'm in there.

[JPNinPA]

Not that I’m aware of. Typically its the rear main seal that leaks.


Never look down on anyone unless you are helping them up - Jesse Jackson