Possible rear end noise.

So I've got a noise at all speeds that matches the speed of the truck. Almost sounds like another engine lol. Trucks at close to 300k. I've gotten toyo open country at3s the 10bply and had them mounted and balanced to the wheels then took them home and put on the truck. It sounds like it's coming from the back. Any ideas? My hope is it's the tires

 

If you just put the tires on and the noise started then its the tires. I'm not familiar with those Toyos but I do know that more aggressive AT and especially MTs will make a lot of road noise. What PSI are you running them at

 

At 35 psi. It's hard to say when the noise started. What's weird is if my windows are down it's almost un noticeable. Now that's its cold out and my windows are up I can really hear it. It's not on acceleration or deceleration it matches the speed of the truck. This is why I think tires. The last 2 sets of tires were VERY loud mud terrains.

 

What does noise sound like? If it was tire hum it’s should happen all the time and get louder with greater speed. Check your out your drive shaft and differential.

 

Why is it hard to pin down when the noise started? It either started before you changed the tires, or after you did. 35 PSI is high for a 1st gen Tacoma.

That being said, you need to start inspecting your drive line to rule that out. Put the rear end up on some jack stands, and rotate the wheels. You're listening for bad bearings or u joints- wheel, diff, etc...

 

assuming you truck has a spare tire. Round up 1 more spare and swap out your rear tires to see if that changes anything.

 

I'll try flipping them around. No spare

 

Just to try to save you some time- I don't think rotating the current tires will make a difference if the tires are making the noise. The point of using a spare (or rather two spares) is to change the whole tire itself. Edit: And just to put this out there- don't swap just one spare on if the tires are different sizes, you'll grenade your diff.

You still haven't clarified if the sound is new since the tires or preexisting. If it's at all preexisting, the tires are a complete red herring, and you need to be inspecting other components in the drive line for wear.