So, since the board switched formats, I haven't posted much....sorry for that. Unfortunately, I also lost my 3000+/- post count

OK...Enough about the site. To my problem....

I'll start with the basics....2000 Xterra SE 4x4 w/ 118500 miles. Oil changes done every 3750-5000 miles, always have the tune-ups and checkups done (check up @ 15k, tune-up @ 30k). I drive 40 miles to and from work (each way) Monday thru Friday with speeds varying from 30mph to 75mph (I drive through back country roads and small farming communities to get to work).

About two weeks ago, during acceleration, the engine spools up like it's in 4wd. I shifted into 4wd, drove a short distance (50'), shifted out and backed up the 50'. The loud acceleration went away.....for three days. Then it came back. It will not go away. It sounds like my 4wd is stuck engaged. When shifting from 1st to 2nd gear, it's a very hard transition. Not as smooth as it once was. I've tried shifting in and out of 4wd, but it just will not go away. Acceleration is sluggish (more-so than normal) and LOUD.

Today, I was frustrated with it and shifted it into 4wd. I drove it probably 7 miles home on wet roads and left it in 4wd. I have not shifted out yet. While in 4wd today however, it drives quieter, shifts more smoothly and generally feels fine. I have an appointment to get it in, but not until AFTER the Thanksgiving weekend.

Here are my questions:

1. Does anyone have any idea what it could be?
2. Is it a common problem with the 1st gen X?
3. Is it difficult to fix?
4. Is it going to cost me an arm and a leg to get fixed?
5. Will it hurt the truck if I leave it as is (drive in 2wd, not 4wd) until next Tuesday for my appointment?

Anyone's input is greatly appreciated. Thanks in advance!!

To start I'd want to know what the ATF level looks like. Truck running, Engine & trans hot and in park...you know the drill....

Saturday.

For the most part the transfer cases are pretty much bullet proof. as long as the shift lever is in 2wd (asuming that the linkage is in good shape) there is no physical connection to the rest of the 4wd gearing.

A flush on the tranny might be a good start, but running around in 2wd is not going to do any furthr damage. Is there any slippage while you drive?

Haven't had a chance to check the ATF level. Last oil change (3500 miles ago), they said both the tranny fluid and the transfer case fluids were just about ready to be flushed and replaced. So, I'm hoping that that's all it is.

As far as slippage, there is none. Just the transition between 1st and 2nd is not too smooth. It has a tendency to almost 'jump' into second gear and lurch the truck a bit.

Ok, maybe I misunderstood. what did you mean by "... during acceleration, the engine spools up like it's in 4wd"? I had assumed that the engine got loud, RPMs shot up but truck didn't move correspondingly. A classic sign of low ATF level. Could be something worse if the transmission is headed south, and has a sticky clutch pack or solenoid in the transmission that could cause those symptoms. I wouldn't spend a whole lot of time worrying about the 4wd transfer case as there's really nothing in there that will slip - It's all metal gears and chains. If it's in gear the tuck will move, if it's in neutral it won't. If it's somewhere in between it'll grind. - you know the sound.

Check the ATF level and hope it's a quart low. ATF flush probably wouldn't hurt but may not help if the trans is very far gone...

-Saturday

Well, the ATF was fine. No problems with the transmission at all. They are doing a transfer case service while it's in the shop though.

The noise was a stuck fan clutch. I'm glad it wasn't anything major....a little costly, but not major.