I'm a new Ford owner, when I engage 4wd I get a fairly annoying whinning / wheering sound that sound like the front end. Only makes sound under acceleration not coasting. No vibration at all. Any ideas would be great!

 

Welcome to FTE!

What kind of surface are you driving on? If on pavement, STOP!

4wd is for limited traction surfaces, not wet pavement, never dry pavement and not even dry dirt or gravel.

Snow, ice, mud, loose hills--stuff you can't pull through in 2wd.

 

it makes the same sounds regardless of the type of terrain I'm driving over

 

Same noise in low range and high range?

 

yes same noise and either low range or high range

 

Check the oil in the diff first, then TC. Since it's the same noise, if it's in the TC, it may be the output shaft bearing, if it's the TC.

Can you run it for a while and check the cases for heat?

Do you have manual hubs? If so, does it make noise when the hubs are locked but the TC is in 2wd?

 

Just had tc fluid changed, oil in the dif was good, tech said it came out of the tc really hot, auto hub not manual.

 

Did the tech find anything in the oil? Did it make the noise before the oil change?

This is the stage in internet diagnosis where we start grasping at straws.

Perhaps you could pull the front DS, put it in 4wd and give it go--see if the noise changes, or if the output on the TC gets hot.



Usually someone with this same problem comes by here about 2AM, so stand by.....

 

Yes the noise was there before and after the tc service. Nothing was noted about the fluid other than ot was broken down and really hot.

 

TC = Transfer case, right? TC should not run "hot" and break down the oil. Takes a lot to break down 90w gear oil methinks.

If it's not shedding metal into the oil, maybe you live with it and see what happens unless you want to pull the TC and go through it.

Perhaps a better idea will pop up.

 

Thanks either way ill prob run it till it blows out...idk its a Ford the reason I had so many Toyota's before this truck.

 

Well, you can't pin troubles with a '98 on Ford at this date. Who knows how it was take care of, and what was done with it....