I have about 27K miles on the truck, and I had something happen yesterday that has never happened before. While towing my boat home from the dealer it seems like the tranny (I will expalin later why I think it is the tranny) began to make a howling noise! It would start as almost like something turned on, as it would ramp up in noise, stay at a level, and then just go away.

I think it is the tranny as it is the same noise that I get when I begin to move from a stop light...kinda like the load is there and then when it gets through a couple of gears it goes away. When I heard the noise (I was on the highway) the rpm's did not change or the speed. Maybe I am associating this with the tranny by mistake, so let me throw this out. Is there something with the engine fan that could have made the noise? I was towing about 4K in boat, and it was only 30 degrees out...so I am not too sure that this could be it.

Any ideas? It has only happened with a load.

 

This happened to me too. EXACTLY ...My air filter was dirty,, the reminder
gauge showed 60% used,, but then it always does. I replaced my air filter
while I still had my RV hooked up, and voo wha la ! no more howl.
Its actually wheezing. I think its trying to suck air around the filter seal
causing the noise. Like blowin a turky call. Anyway be sure to clean up
the air box real good, don't leave a single spec in the bottom half,, CLEAN!
This was the case for me, hope this helps....HOUTEX

 

May want to check your u joints.

 

The air filter was changed 7K ago, and this only happens (or has happened) since I towed this year. the noise when on the highway was not constant, it sounded like it would kick in (almost sounded like something was turning on as it would ramp up in sound) for a few minutes and then the noise would go away...even at a constant speed. Could there be something with the fan clutch?

Again, when I was at a stop and started off...it sounded like a tranny was cold as it would do it then everytime but as I gained more speed and went through the gears it would go away.

 

Sure it ain't the fan coming on for the a/c? My '03 did that even in cool weather with the a/c in any mode that used the compressor. It would howl when I took off and then shut off at about 25-30mph. The fan is electronically controlled like a Horton so it wouldn't necessarily have to be hot outside. No wind across the condenser could bring on some higher head pressure in the a/c high side and cause the fan to come on.

 

My 2004.5 has a "Owl" type noise during exceleration and decelaration between about 20 to 25mph. From some of the post's I've read it could be the intermidiate bearing on the drive shaft. It would get louder when it was real cold. On warm days, it's not as noticable. Off to the dealer I go......