I just replaced the water pump on my 97 Ram Wagon (3.9 V6) I had a heck of a time getting the fan clutch assembly off. The water pump is the one with the pressed on pulley. My question is: when I screwed the thing back on, there's not a good way to tighten it. I used a pipe wrench on the big nut but the pulley started slipping on the belt even with extra tension on the belt. Any suggestions?

 

Yes, don't worry about it. The nut is self tightening due to the rotation of the water pump. You have it as snug as you will get it. I have done three different pumps on these Magnum engines (2 vans, 1 pickup) and no problems.

 

Thanks, I was a little worried about not being able to "cinch it down" and couldn't find any info on it.

 

The Dealer uses a special wrench tool to hold the pulley when installing or removing the fan clutch assembly. If you look on the front of the pulley you will see small holes -- this is where the tool fits in. Like MAR said, no need to worry about getting it too tight on reassembly as the clutch has a reverse thread pattern.

I would recommend some anti-seize compound on the threads, however, to make the clutch easier to remove next time around.

 

A strap or chain wrench wrapped around the pulley does a nice job of holding it from turning.

 

Brilliant application for the "kinda silly" strap wrench of Billy Mays fame. I think Sears has added a few different size strap wrenches to their Craftsman line of tools. Finally a decent reason to own a set.

 

I have never been impressed with a strap wrench. Now a chain wrench I do like even though I don't use mine much.

 

I've used a chain wrench too, but they make me nervous. Unlike a strap wrench, they can scratch or gouge the pulley, and that would make for a very short lifespan for the belt.

 

A trick I use is to cut the old belt and wrap a piece of the belt onto the pulley then put the chain wrench over it. So far no problems and cheap insurance.

 

Wouldn't that be the equivalent of a strap wrench?