Hello!

I have a 93 Dakota 4x4 with a v8. I haven't had it long and have noticed that when I hit 40 mph, a humming sound starts. It sounds as if it's coming from the 4 wheel drive selector. If I grab the selector it feels like it's vibrating a bit. Almost sounds as if it's stuck in 4 wheel drive.

Any ideas what would cause that sound and how to fix it?

I appreciate any thoughts/info!

 

It could be your u joints. Check them for play when you can.

 

If the 4wd was engaged you will feel the steering binding. The transfer case shifter does move/ vibrate. That is normal.

 

Did you ever get this resolved?

If not, I was thinking it could be road noise. On my dakota if you unscrew the 4 or so screws that secure the boot and pull the boot up, you can look right down and see the ground so there's not much noise dampening there.

Also, it could be your shifting linkage, if you ever wanted to you could put some "never cease" in the areas where the different sections of linkage connect and ya never know...just might fix your problem. Hard for linkage to make a vibrating sound when it has a good wad of some type of grease in there, LOL.

 

Thanks for the recommendations. I had a neighbor help me check the u joints and he didn't think they were bad. He's owned trucks before so I trust his opinion; however, I'm not sure what type of "play" is bad.

It does definitely change out of 4 wheel drive so that isn't the issue and the noise definitely isn't road noise. It sounds like something is winding up. It happens or at least becomes noticeable as the speed reaches 40 mph and then winds down as you slow down. It definitely isn't a normal sound.

I changed the transfer case fluid and it had no effect on the noise.

 

could be the power steering, my former room mates car made the same noise. i took it in for her and found it was the power steering, could even be a bearing

 

I took it out for a spin to listen in some more.

The winding/whirring/humming does start at all speeds. It is just light at low speeds. If I shift the transmission into neutral, it lessens the sound significantly, not completely but almost. So that would lead me to believe that it has something to do with the trasnmission.

The power steering fluid is a little on the low side so I'll top that off to make sure.

 

I wouldn't "top off" any fluids, they all need to be at the indicated level that is shown either on the dipsticks/ paperwork/ or manual. Unless by "top off" you meant fill to the indicated line or proper amount.

It could not only be the transmission making the noise since when you shift into neutral the engine rpm's also change. If it were me, I would check the serpentine belt and all of the engine pully's, one of those might be the cause of the noise. I've had experience in this area as well, unfortunately...lol, and the idler pulley and tensioner arm pulley both are really cheap (around $20 new) so if your willing, you could try changing pulley's or the belt which is also inexpensive.

 

check your u joints first.

 

If it is at all speeds your tires could need balancing.