Hub Turning

[motormayhem]

Hey I took my truck off-roading today for the first time and noticed you can turn the front hubs to lock or release. I had read somewhere that I could just use the 4x4 shift in the cab to go in and out of 4x4. What does the lock/release do on the hubs? Before I noticed them they where on release and the transfer case ended up cracking when I was climbing some rocks and I don't think 4x4 was working even though the shift in the cab was in 4x4.

So I'm guessing for paved road driving the hubs should be set to release and the shift be in 2wd and off road should the hubs be on lock and use 4x4 shift in the cab to go to 4x4?

 

[Croatan_Kid]

To use 4 wheel drive, the hubs must be in the LOCK position and the shift lever in 4 hi or 4 lo. For 2wd, obviously, 2 hi and the hubs should be unlocked.

If you put it in 4 hi or lo and don't lock the hubs, it's still in 2wd because the hubs are not engaged.

 

[motormayhem]

To use 4 wheel drive, the hubs must be in the LOCK position and the shift lever in 4 hi or 4 lo. For 2wd, obviously, 2 hi and the hubs should be unlocked.

If you put it in 4 hi or lo and don't lock the hubs, it's still in 2wd because the hubs are not engaged.

It was in 4 lo with the hubs unlocked when the transfer case broke. What could have caused the case to break? It broke all the way around the main housing just driving up a steep rocky hill. The truck was stuck, but the case didn't hit anything it just cracked and spilled oil everywhere. Also is it on to go off roading with the hubs in the locked position and the truck in 2 hi until I need to shift into 4 and then unlock the hubs before leaving the dirt?

 

[rosco]

You just over-torqued the T-case. Usually, you break an axle or twist off the drive line. You, no doubt had ecxceptional traction on the wheels, and the Transfer case didn't like all of it at once.

Lee in Alaska

 

[rosco]

You just over-torqued the T-case. Usually, you break an axle or twist off the drive line. You, no doubt had ecxceptional traction on the wheels, and the Transfer case didn't like all of it at once.

Lee in Alaska

 

[Crash_AF]

Yes, standard practice is to lock the hubs in before you get into trouble, drive around in 2wd until you need 4wd. Just remember to unlock the hubs before hitting the road home though.

Later,
Joe

 

[Recovry4x4]

Older trucks didn't even have lockout hubs, deuces still don't unless added. When living in the rustbelt I would lock my hubs in come winter and leave them locked until spring. No damage, just stuff turning that doesn't need to turn. Upside is that if you need AWD, you just grab the transfer case. Most vehcle mfrs recommend that you lock in the hubs for a few miles each month to promote lubrication and warm everything up. Low range can generate lots of torque to driveline components, I'd avoid that with the hubs unlocked.

 

[Texis]

The NP208 is not prone to breaking, it's a "decent" T-case, for an aluminum chain drive. My guess is that the torque hitting the case with the front end unlocked created an unbalanced load on the case, it split because you had no load coming from the front axle, to balance it out....just a guest.

If you plan on using the truck off road, find an NP205 transfer case and the correct adapter. The NP 205 is a cast iron, gear driven unit. You need a new case anyhow, why not upgrade. NP205 are easy to find. Check the 4wd boards and forums. I've seen them for $100-$250.

 

[crusty]

It's highly unlikely that the T-case broke from torque. The most usual cause is a frozen slip yoke or the wrong length drive shaft, or a U-joint bottoming out, particularly on the front. Check your pinion snubbers and make sure you don't have a broken shock allowing the suspension to extend too far. The NP-205 is much stronger but if you don't fix the cause of this damage, It will just break the transmission housing next time.

 

[KenzMan]

My friend had a large transfercase (cast iron) blow apart as stated , we were told it was out of a duck but it only had one rear output so i'm not sure . It had the fourth shaft for the opposite turning front and the only thing we could find the caused it was bad bearings inside . There was no siezed yokes , all driveline angles are awesome with all good u-joints , he wasn't stuck or even being hard on it . He got in the truck and just started moving when there was a little clunk and it stopped moving only to find out half the case was on the ground . Prior to that there was no oil on the outside of the case and entire area along the crack looked like fresh meat .