Would it be a good idea to replace the belt pulley's when you replace the alternator? would be on an 02 van 5.2.

 

do you mean the idler pulley?

 

basically any or all of the pulley's like belt tensioner pulley, idle pulley and such.

 

really depends if the bearings are shot. My idler was shot. How did I know that. When the belt was off I just spun the pulley. If it sounds like it has rocks in it, it is bad...
Good luck.

 

Agree with Funair02 when the belt is off spin the pully by hand should it spin freely and have no play why change it?

 

I have had and seen several that seemed good when changing the belt only to find out the old bearing went very quickly after the new belt is installed. Personally I recommend and do change my idler, tensioner pulleys when I change my belt. A few dollars now saves many headaches later!

 

By replacing the pulleys with oem pieces can't hurt but not me.

The War Department(wife) drove a 5.9 Dakota 150K I have
two 5.9 Vans which I have put at least 200k+ between the two.

Out of the three motors the only things to fail was a cracked exhuast
manifold and a starter both on the same van.

We pull our sailboat from Massachusetts to Miami once a year and use the same van pull a camper to Quebec City each fall we have never had a breakdown( knock on wood).

You can replace a lot of things but if it ain't broke and looks/sounds normal I don't touch it.

Just my opinion we all are allowed to have one.

Regards