so, while i was getting off the beach from a very light ride..before i disengaged my 4wd..i heard a loud BANG. sounded like my axle wasnt engaged, then suddenly dropped in 4 while i was driving. sand kicked up in the air and all too so i knew it randomly dropped in. but, i already had it clicked in 4. weird. so, im driving down the road and i hear this whizzing noize. sounds like a nest of bees inside my hubs. then, i stopped, dropped her in 4 and suddenly...no buzzing. so im thinking its my hubs. furthermore, i disengage it to see if maybe it was just temporary..nope. sound came back. then im back on the beach the next night with a few buddys and im down pretty far in some really loose sand and shes kickin out some R's. and once again while im in 4, she starts to get stuck. then like before..BANG! 4 kicks in. followed by several other little clicks and pops. then that was it for me. i high tailed it off the beach hoping nothing would go wrong. then i hit a loose spot on my way out..she wasnt in 4 again, while the 4wd light was obviously on. it got so bad that it was just popping multiple times now. and the 4 only locks in while in reverse. any ideas on what to do? buddy of mine told me my hubs are blown out.?? any input is highly appreciated. these twin beam axles are annoying, i never worked on em before..so, im clueless. thanks.

 

auto hubs or manual hubs? sounds like you also have electric tcase correct??

if you have auto hubs i would get those replaced with some manual hubs. see if the problem continues, if it does i would suspect some damage to either the Tcase or the electric motor that engages the tcase.

 

Sounds like your auto hubs are prob smoked, bearings are probably gone, if you hear whirling sounds, whizzing noises its definitely a bearing.

 

Remember that if you are moving while in 4H, and "disengage" 4H back to 2H, that just means the transfer case is no longer powering the front drive shaft. The the road continues to turn the front wheels, the auto hubs are still locked, both axle shafts are turned by the wheels, and the front differential turns the front drive shaft. So all of that rotating mass and frictional loss continues.

When you stop, and go the opposite direction you were going when you disengaged 4H, THEN and only THEN the auto hubs will disengage themselves, and both axle shafts, front diff, and front driveshaft will come to a stop finally. Now ALL of the front drive system is totally disengaged.
The auto hub unlock distance mentioned in the manual is 10 feet, they wanted to cover all possibilities and not have people come back under warranty and complain over a couple feet. My Bronco's unlock within about 2 feet of opposite travel. One unlocks before the other, I can hear them do it.

The whizzing/clicking sound in 2H after being in 4H can be a hub that didn't lock, and remains unlocked. The front wheel with the locked hub turns that axle shaft, which turns the front diff, with the other hub unlocked, the action of the diff tends to spin the unlocked axle shaft the OPPOSITE direction, against the direction of travel. The unlocked hub now ratchets wildly.

The other scenario that causes whizzing/clicking is a hub that didn't UNLOCK after the driver properly followed the unlocking procedure. Here again, one front wheel drives everything, and the other hub is clicking.

It's possible they just need disassembly and cleaning. Certainly can not rule out part breakage.

You can make auto hubs last longer by avoiding abuse, abuse like putting it into 4H at a stop, and then tromping on the gas, causing a big impact load on the auto hubs when they go to engage. Or being stuck and spinning one or more rear wheels fast so T-case RPM is up, then engaging 4H with a bang.
When I was looking for a Bronco years ago, I found many that had this problem. No doubt that manual hubs are stronger, just by the act of manually engaging the hub means that there isn't an initial impact load, because you have to be out of the truck and next to a wheel to lock the hub!

 

Anyway... check the link in my signature (Fron End Rebuild) in order to check your hubs, it doesn't matter if they're auto or manual, I've covered both since it was a replacement.

 

I had a bad clicking noise on my 93' on the passenger side shortly after I got the truck..

I went to Advance and got some MileMarkers for like $60 (or less with a coupon).. took 20 minutes to install them.. no noise since.. The MM were part number 302.. not the all stainless ones.. but the 'street' ones.. Keep in mind my auto-hubs had the 5 screws.. so nothing was needed.. if you got the 3 screws you will need an extra kit..