We tow our little jet boat with our van, but have noticed an odd noise that sounds like it's coming from the rear end, but we just can't pin point it.
I can almost always make it do it around 38-40mph, and it only does it with the boat attached, and not all the time, just periodically. Except holding around 40mph.
It sounds like something is slightly grinding, almost like a chain dragging, but I've checked that.
I started to think it could be a few different things, rear rotors, bearings, brake pads, etc... But it did it once while we were stopped.
So now I'm a little worried it might be the tranny, but the sound is coming from the rear.
Anyone else encounter this?

 

So, it only does it when you're towing, yes? I'm thinking with the little bit
of extra weight on the rear, the shocks are down just enough to cause some
rubbing. I'm thinking the exhaust may be rubbing the heat shield, or
a frame rail somewhere. By hooking up your boat (WHEN THE VAN IS OFF and COLD),get
under the van, and feel around at how close the complete exhaust is to various things.
If its minor, and only when you're towing, you can probably leave it alone. It might be
as easy as bending an alluminum heat shield just slightly out of the way for more clearance.