Cool site, glad to join.
91 XLT 4X4 W/ 198,000 ans still rolling. No major problems except now 4X4 not engaging. I can hear the relay in the back clicking and volt meter dips, so it appears its trying to kick. I hate giving money away. Any ideas on what I can do.
Anyways, FORD's Rule.
Thanks to whoever created this site.

could it be your hub locks? those tend to go bad after that many miles.

mwatkins

First of all, welcome to the board, it is a great place to find anything you need to know about your Explorer.
Try going to this link http://www.glue.umd.edu/~singletn/web/pages/tcase.html
Your problem is most likely the transfer case shift motor, it can easily be repaired by yourself in a few hours.
Good luck.

If it ends up being the hubs, you can get the warn manual's here: www.4wheelparts.com. It's the best place that I've found, but if anyone else has better, lemme know cause I'll be getting them soon myself...

Thanks for the link. It worked out great. But now when the 4X4 is engaged there seems to be a trouble with either the auto hubs engaging or something else. I will be driving and something jumps (knocks, thuds, etc.) every so often. Especially if I step one the gas. It feels like it is coming from up front.
Any ides?
Thanks

[I will be driving and something jumps (knocks, thuds, etc.) every so often. Especially if I step one the gas. It feels like it is coming from up front.

Don't use your 4x4 on dry pavement. Make sure you only engage it on dirt roads.
If it still makes noise on dirt then chances are your auto hubs are going bad, if you decide to replace them then you should switch to manual hubs they are cheaper and more efficient.
Also, check you front drive shaft and axel shafts. Bad u-joints will also cause banging noises.