no transfer case fluid change ever

Hi;

After driving my 90 XJ (4.0L, AW4), with NP231 transfer case, for about 270K miles, I learned that the TC fluid needed changing even though the truck has been in 4WD only 3-4 times in her life. Like a dummy, I wrongly assumed that if I don't use 4WD I don't need to change the TC fluid. I drained the black fluid and 1/2 quart came out. I refilled with fresh DEX III and Seafoam Trans Tuner, drove for a week, and changed the fluid again. This time the fluid was all red.

Since the vacuum disconnect on the front axle is all shot up, I can't test to see if the TC and the 4WD work.

What damage could I have caused the transfer case becasue of running without fluid change for such a long time? Should I assume the TC is all ruined?

TIA for any clues ......

It still works right?
Too late to worry about it now.

Any problems associated with a lack of lubrication would show up in 2wd use.

Therefore, if the transfer case is functioning normally in 2wd and does not make any funny noises, do not worry about it.

Most gear boxes, including standard transmissions, differentials and transfer cases are designed to function for many miles over many years without a fluid change.

IMO it is much more important to maintain the correct fluid level than to change the fluid. Even old, black fluid is much better than none at all. If only 1/2 quart came out, then you had not been maintaining the level. You should check the level regularly, at least at every oil change; more often if you believe it is leaking.

Any problems associated with a lack of lubrication would show up in 2wd use.

Therefore, if the transfer case is functioning normally in 2wd and does not make any funny noises, do not worry about it.

Thanks. It's good to know that any problems would've surfaced in 2WD mode.

As to funny noises, when the truck is started cold, I hear a faint ticking noise from the TC area which goes away after about a minute. I can't tell if it is from the case itself, the linkage, or something else in the vicinity of the TC. Then again, with the age/mileage of the truck, funny noises are more the rule than the exception.

Thanks for the replies.

For that ^, I'd search "flexplate" / "flexplate bolts". They tend to loosen up and make the 'ticking" sounds.