4 X 4 sytem

hey guys would appreciate any help you could offer, I've got a 2000 rodeo and the truck has been great the problem i have is with my 4 wheel drive when i hit the button it turns on right away but when i shut it off it wont disengage and the light keeps flashing, if i keep driving it will shut off about a mile later, also i know there's a resavour under the from of the truck thats suppose to activate the front diffs and my question is whats the resavour for and does oil run throught the lines to engage and disengage the front diffs, again thanks and your help would be appreciated.

slicker- Sounds like your sift on the fly (SOTF) actuator is binding up a bit. The SOTF actuator on 1998+ rodeos is basically an electric motor that moves a fork that slides/splines together the left front (driver side)axle. It's mounted on the driver side of the front axle. The SOTF actuator does hold a small amount of axle lube, and should be checked & changed every 3yrs or so. This is a very common issue that can be avoided if you cycle your 4x4 a few times a month to keep this actuator oiled & free moving. I engage my 4x4 as I'm rolling out of my driveway & then turn it off before I hit the street as to not stress the drivetrain on dry pavement. If you just turn your key to "on" & press the 4x4 button, you should here the SOTF working. G/luck!!
Joel

I too love my truck, except........My 2001 Rodeo does the same thing except it will only disengage when you turn the corner. I took it to the dealer in which I purchased it from...I was told:

It is normal, read the owners manual, it states you may have to turn the wheel to disenge (This is incorrect, and it will ONLY disengage at a full turn and worked properly for the first 40K miles)

After further conversation......

I was then told that it was because we purchased two new front tires...They were the SAME make etc as the tires that were originally on the vehicle..(Could someone please tell me what would happen if you had to put the full size spare on - would it be required to purchse four new tires so they are ALL the same circumfrerence??)The service manger is claiming that It will not disengage because the tires are not the same in diameter....Even 1/4" off will do this....Is the 4x4 system this fragile???

Also, it popped out of 4H while driving....twice....after this 4x4 (SOTF) would not disenge..

Isuzu headquaarters told me if thats what they told you, there was nothing they could do.........Great customer service huh!!!!!

My next step is NTHS or Lemon Law if I can not get it fixed...It is still under warranty...

Any suggestions would be appreciated!!!!!!!

What Isuzu is telling you is 100% correct!!! If all 4 tires are not EXACTLY the same diameter, the 4x4 drivetrain will bind, will not engage/disengage properly, and will pop the xfer case out of 4hi due to the binding. That's just the nature of ALL 4x4 systems. There is no "give" in the system to account for different tire rotational speeds cause by slightly different diameter tires. In 4x4 mode, all 4 wheels are mechanically locked together by the drivetrain and are forced to rotate at the same speed. Different (sized) tires place HUGE forces on the drive shafts, axles, gearboxes, etc- that are trying to spin all wheels at the same speed. Don't put your truck in 4x4 unless you have a complete matched set of tires. Also- be sure to rotate your tires every 5000mi so they all wear evenly, or you'll wind-up in the same boat again!! Sorry to be the bearer of bad news. Hope it works out for you.
G/luck
Joel