Strange sound after changing transfer oil?

[Ghostrider]

I changed the transfer oil at 65K on my 2001 4Runner. I then took it on a drive and swear I hear a "whirring" sound when I put it in AWD above 30 mph. Never heard it before but I rarely use AWD so it could be there all the time. I used 75w90 dino and had the transfer case done at 20 and 40k at the dealer. I was going to do the front diff but cannot get the drain plug loose. That thing is sealed inthere until I can get it on a lift a use a long cheater bar. Any ideas?

 

[chad99]

i noticed that on my 4runner also when its in AWD its like a faint whirring sound but have to have the radio off to hear it and with no one in the truck talking.

 

[pat161]

My 02 does the same thing, a very faint whining sound when in 4wd. Mine did it w/ the factory fluid and does the same thing w/ Redline MT-90. My 2000 w/o the multi mode did not make the same noise so I just figure it has something to do w/ the center diff and seems it works fine and is smooth I'm not worried about it. Mine is under warranty until 09 or 100k so if it is an issue it has almost 3 years and lots of miles to blow up and be fixed for free.

As for the front diff I would avoid a long breaker as those bolts are very easy to round off being hex head or what have you. Soak it real good with PB blaster for a day or two, then put the ratchet on it and hit it with you hand, or a hammer, that will mimic an impact wrench more than just applying steady pressure. I never got the plug off my 00 as I stripped it the first time, using the above technique the plug on my 02 came off so easy I was ashamed of my earlier failure.

 

[wayneboard2]

this is odd because I just logged on to post about this very topic and found this thread. Last week I changed my front and rear diff fluid and my transfer case and have a slight buzzing in the floorboard on the drivers side. I can't figure it out. I have no leaks, the fluid level is up to the fill hole and I can't find anything loose. I don't know if I just noticed it now, but I've had this thing for 3 years so figured I would of noticed this by now. I sure hope some mod or vet can help us out, it's kinda worrying me.