Alright, a while ago, I replaced my power steering pump due to a leak at the shaft seal and air intrusion. Everything works great and cured my fluid-foaming problem at cold temps.
However, when I replaced the pump, I noticed some thin, hairline cracks near the center of the pulley near the steel sleeve that gets pressed on to the pump shaft.
A little while later, the pulley is makong noise now. Even with the car off, I can try to wiggle the pulley and can hear the plastic "creak". Obviously, I plan to replace this.
Remembering from the other cars I've owned, the plastic power steering pulley was a 4.9 thing introduced in the '90's. However, the 4.1 and 4.5 have all steel power steering pulleys (I've confirmed this with my '90 4.5 and dads '89 4.5. I could replace the pulley with the correct plastic one, but, for piece of mind, I'd rather replace it with a steel pulley if the diameters are the same. Does anyone have any available info that confirms the interchangeability?
You're lucky, Dorman sells a replacement for your model. Okay it's plastic, buy two.
I have a 4.1 and my pulley is warbled a little. Nobody makes a replacement for the pump on the 4.1. I bought a junkyard replacement and it was also bent. So I've been looking at pulleys from other vehicles and while I can get pretty close there is always something just different enough. One of the Jeep pulleys was really close (they use the same pump) but the offset was backwards since they run the belt behind the face instead of on top of it. From what I recall the other 4.x pulleys had completely different shafts. If you want to go on a similar quest, go to dormanproducts.com and find the power steering pulley PDF catalog, look up your part and write down the dimensions, then look at all of the other parts to find similar dimensions.
Just FYI 4.9s in 93 had all steel pulleys on them also so you don't necessarily have to go back to a 4.5. Both my 4.9s are steel so I am pretty sure they are OEM.
Mine is wearing out though, I have had to replace the PS pump 4 times now so the pulley has been removed and installed several times. This last time I had to run a washer and bolt through the pulley into the pump to keep it pressed on, otherwise the pulley would slide off and misalign the belt making the car un-driveable, just something you may want to keep in mind if you are going to be pulling junk yard parts.