Driveline noise

[M-three]

My explorer has been making a 'howling' noise that appears to be coming from the transmision/transfer case area. Im not quite sure where it is coming from because i only hear it when the truck is in gear and the engine is spinning over 1500 rpm. It does not make the noise in neutral or park, only when the truck is moving. i think it goes away below 1500 rpm, and over about 4k rpm. any ideas?

 

[Creager]

manual tranny? output shaft bearing? or is it the input shaft bearing thats known to go on these things?

i dunno id change the fluid in those things and see if that helps. which it probably wont, once these things start to make noise they usually dont stop.

howling... explain it more... it goes up and down with engine speed? or does it go up and down with the vehical speed?

engine speed, you are correct to look towards engine, tranny and the transfercase (in some instances)...

if it goes up and down with vehical speed you wanna look towards transfercase, u-joints, and rear end.

2wd?

OK so you only hear it in GEAR? hrmm.. so you sit in the driveway, and you pump it to 2.5k RPMs (i guess when the noise would be at its loudest) you dont hear the noise?

Transmission maybe. i dunno im no expert. just using process of elimination.

 

[M-three]

Auto trans. The noise gets louder with engine speed. Probably worst between 2.5k and 4.5k. Really bad at highway speeds (75-80mph). Exactly, sitting in gear hitting the gas I do not hear the noise. and it is a 4wd.
Would adding some fluid the the transfer case help. i took out the fill plug on it today but really am not sure how to check the level. any advice would be appreciated. thanks for the response Creager.

 

[Creager]

Auto trans. The noise gets louder with engine speed. Probably worst between 2.5k and 4.5k. Really bad at highway speeds (75-80mph). Exactly, sitting in gear hitting the gas I do not hear the noise. and it is a 4wd.
Would adding some fluid the the transfer case help. i took out the fill plug on it today but really am not sure how to check the level. any advice would be appreciated. thanks for the response Creager.

yr gonna want to get a haynes manual for sure, because ive never been under your year truck

normally you just fill up to the fill hole. Bascially till you cant put anymore in. Normally thats how it works

If its going up and down with engine speed then it can be Numerous things. But it will be probably be centralized around the engine or tranny. Id start looking at the engine pullies first. Idler puller going bad?

Does it sound like it might be comming from the very front, like where the power steering and airconditioning is?

 

[M-three]

thanks for the advice. it sounds like its coming right from under the front seats. thats what made me think tranfer case. im going to try adding some more fluid tomorrow. all i need to add is regular mercon III right? Wouldnt the idler pulley make noise even when the truck is out of gear?

 

[M-three]

sorry i messed up my first reply. when i sit in the driving in neutral or park, i DO NOT hear the noise. i only hear it moving and while in gear. even if i am moving and i put it into neutral i wont hear it when i give it gas. hope that makes sense.