Hey all, I have a 94 trooper that has started intermittently banging while in 4wheel drive. I thought it was the hubs and replaced the old auto hubs with manuals but that wasn’t it.
a mechanic said it could be the rear differential that’s bad and the banging is the slip. It only does it in 4x4 and doesn’t slip even when driving the same dirt hills in 2wheel dr. Can’t decide where it is coming from. Loud bang seems to come from both sides and can’t really tell if it’s the front back or both. Any ideas? Don’t want to drop the money on a rear diff to find out it wasn’t it either

 

How could it possibly be the rear differential? It gets the same workout in 4wd or 2wd, I think the mechanic meant the front. Does it make the noise with the front hubs unlocked and transfer in 4wd? Does it make the noise with the hubs locked and the transfer shifter in 2WD? By changing out the auto hubs with manual hubs you have the ability to isolate different parts of the front drivetrain. It could be the differential or it could be U-joints on the front shaft gone bad. Did the noise start all of a sudden?

 

Ok so, forgive my arrogance on this one but no one ever talks about “why” they change their hubs to manual locking hubs, I have a 92 trooper LS and I don’t understand what the point is of changing the hubs unless your going all out rock climbing status.... fill me in brothers what am I missing

 

Auto locking hubs are perfectly adequate for probably 90% of 4wd owners. If you're just occasionally going to leave the hardtop, drive on the beach, across some wet grass, maybe in a light snow or, crawling up a rough dirt road so you don't beat up your suspension having to keep up your momentum with a 2wd. They save having to get out in the dirt to have to lock in the hubs. The shortcomings are evident if you're a serious off-roader, such as a hunter or, serious fishing enthusiast. If you get into a situation where you're stuck up to the axles in a rut, you quickly become familiar with the "rocking" technique where you frequently and rapidly shift back and forth between fwd and reverse. Auto locking hubs will take a beating since they must disengage and re-engage every time you change directions. With an automatic tranny the chance to do some serious damage is even more likely. You could get to a situation where when you dis-engage the transfer case, the hubs won't fully unlock resulting in a metallic grinding noise. That's when most people will switch to Warn Locking hubs rather than replace with another set of auto hubs.

 

Well since the OP hasn't been back since he posted 6 mos ago, it doesn't really matter.