Tranfer Case needs replacement?

[BB33's]

Hey guys. My 1995 bronco has started acting up and I am lost as far as where to look for the problem. The problem is that when I put the truck is in gear Forward or reverse it doesn't matter, and i give it the gas to take off There is a clunk you can feel in the drivetrain. I have replaced all the u joints in my driveshafts and even had the rear, with that stupid double cardan joint that cost me 250.00. My rearend is rebuilt so I don't belive it is anything there. I do have a truetrac and I know the Detroit locker likes to clunk on streets. The reason I Am leaning twoards tranfer case is that when it is put into 4hi it makes an enhanced version of the clunk. Any input is appreciated. I am a mechanic and replacement or rebuild of the transfer case is not a problem(if that is what it is)

 

[Justshootme84]

You might also want to check the u-bolts, leaf springs and the shocks on the rear axle. You may have something loose, or having a problem with axle wrap. Have you checked or changed the fluid in the t-case? A weak point in your B0rg-Warner 13-56 t-case is the oil pump locating tab inside the case ,which can get worn down. That will eventually lead to sudden pump failure. But I've seen more pump failure due to lack of fluid. You might want to disconnect the driveshafts from the t-case, and check the t-case yokes for excessive play. Either in and out or rotational, too much play is a sign of bad bearings. More than 1/2" of play is way too much in my opinion. JSM84

 

[Broncobill78]

You say it makes a clunk but it still takes off right ? It's not like it's making noise and not going anywhere. I really wouldn't start considering the transfer case until it STOPS moving anywhere. Do you have locking hubs ? If so a good diagnostic is to remove the rear driveshaft & then put it into 4WD. IF the clunking goes away then you've narrowed it down to something in the rear axle (loose leafs, too much backlash, whatever) and eliminated the rest of the drivetrain. 4HI might simply enhance the clunk because the ratio is better and you're slamming it harder when it engages. Try removing the rear shaft entirely and see what it sounds like.