OK.... I have no idea where to look for the vacuum lines to see if they are good to go on my 86 GW. The previous owner put manual hubs (No, I don't know why) on and they are not locking up. I'm guessing there is a vacuum line somewhere not engaging. When I throw the switch (OK, flick) on the dash from 2wd to 4wd I hear the vacuum 'thump' (For lack of a better sound effect) from the dash and do not hear anything else coming from the T-case. (NP 208 or 209?). I crawled up under and found an oil leak coming off the rear main seal (Joy...) and no damage (JOY!) to anything. The drive shaft IS attached (Just HAD to double check) and the there appear to be 2 'lines' running to the critter. One on the pass front which appears to be electrical and then one on the P/S rear which I have NO clue on. Any schematics, step by step help or whatever would be awesome.