No 4wd, I can hear the t-case shift

[mel2002]

I was recently given a '90 Bronco that has been sitting for over a year. I am slowly trying to work out all of the minor issues that have been neglected for so long but am very unfamilar with this era (I have previously owned a '76). I was told the 4x4 worked when I picked it up, but on the first snowfall I found out that it does not work. I can hear the t-case shift when I hit the button so I suspect the locking hubs. From what I understand from another post that the hubs use a cam system to engage/disengage. Is this true? Are there any vacuum lines? Where do I start to trouble shoot? Do I need to clean/**** the hubs? If so any tips?

 

[Broncobill78]

I was recently given a '90 Bronco that has been sitting for over a year. I am slowly trying to work out all of the minor issues that have been neglected for so long but am very unfamilar with this era (I have previously owned a '76). I was told the 4x4 worked when I picked it up, but on the first snowfall I found out that it does not work. I can hear the t-case shift when I hit the button so I suspect the locking hubs. From what I understand from another post that the hubs use a cam system to engage/disengage. Is this true? Are there any vacuum lines? Where do I start to trouble shoot? Do I need to clean/**** the hubs? If so any tips?

I can only offer some tips since I my 88' is the first truck I've had with these auto hubs and to be honest with you I intend to replace them with a manual set. Yes, you can clean & **** them but I'd get a good manual before taking one apart. Once they're unlocked by pushing the button in the cab, they cam forward thru the rotation of the wheel & then disengage the same way when you drive in reverse. That's actually one of my issues with them, I understand that they have a tendency to disengage when you drive in reverse and from time to time I *want* the truck in 4wd while I'm in reverse so that sort of thing would drive me freakin' nuts. So I guess you can grab a manual and a allen wrench & go to town or you could consider just swapping in a set of manual hubs and being done with it. Either way you're taking the whole thing down but if you keep the auto hubs it would probably be a good idea to clean & **** everything as well as you're able.

 

[Justshootme84]

I agree, you should take out the hubs and check the grease. OFten, the grease will harden up and the hubs will fail. When you push the 4x4 button, and the 4x4 light on the dash comes on, and you hear or feel the t-case shift, have someone watch the front driveshaft while you slowly move forward. Then watch if the ds does not move when you switch back to two wheel drive. IF the ds turns in 4x4, the problem is in the front TTB axle. I would also suggest switching to manual-locking hubs, as the cost is less than $100. The auto hubs, even if they're working at the moment, have a habit of failing when you need them the most. Like stranded 2 miles from the nearest road, JSM84