1997 4.0L Idler Pulley replacement part

[dmorris0821]

I need to replace the idler pulley in my 1997 4.0L. I purchased the new pulley, but it is different than the one I pulled off my Ranger. The old pulley has edges on the side to keep the belt in place. I have included photos of the old pulley The new pulley does not. I just want to make sure I get the correct part before replacing Any help is greatly appreciated. 

 

[franklin2]

If you look on www.rockauto.com, most all the replacement pulleys they sell do not have edges. They have one that has grooves and runs on the other side of the belt, I do not know what that is about. But all others are smooth with no edges. Rockauto is a good place to go to see options and different manufacturer part numbers for parts.

 

[SenorNoob]

IF everything else is in good shape, an smooth pulley works just fine without the edges. I'd be willing to bet that it's significantly cheaper to manufacture is why the aftermarket is like that.