R50 Transfer Case Question

[RBPathy]

I'm new to the Pathfinder world having purchased my 03 LE with 175k miles on it just 5mths ago. It had quite a bit of vibration up front especially when it was in "auto" (which I incorrectly assumed was just like AWD until I was schooled). My first fix was to replace the U joints which helped some, and removing the 1.5inch spacers from the hubs helped a bit too.
When I had it up on blocks, however, I noticed that the front wheels were turning even in 2Hi. It makes sense that they'd spin in 4WD or even Auto when lifted off the ground, but I feel like 2Hi should completely disengage the front driveline from any torque. Am I off base here??? Any input is appreciated.

BTW...I also drove it around without the front driveline in and had no vibration at all up front so I'm pretty sure the vibration is either coming from a bad front driveline or the transfer case. So I guess the next step is to pull an old front driveline from a junkyard and give it a shot.

[mdmellott]

Given the front driveline is not fully disengaged while in 2WD, there is something off with your transfer case system. The All-Mode 4WD transfer case in the LE is a complex system. Its like a second transmission, with clutch plates, hydraulic solenoids and valves, oil pump, and a transfer motor. This section of the factory service manual will help you get familiar with it. https://www.nicoclub.com/service-manual ... 3%2Ftf.pdf
Replacing the front driveline isn't the go-to next step in figuring out what is wrong.

[RBPathy]

Thanks for the input, I thought so as well. I did take it into the Nissan dealer and they told me that nothing was wrong with it and it was just residual motion from the transfer case. I really don't know what that's supposed to mean, but I called them back to ask again and I got the same answer.
I realize the transfer case is pretty complicated, but if Nissan tells me nothing's wrong I don't really know what else to do at this point... I just have a feeling that something is not quite right. Any ideas?

[mdmellott]

... just residual motion from the transfer case. I really don't know what that's supposed to mean,...

Yeah, that's an odd response. If the ATF in the transfer case is really old, I would start with changing that out to see if it makes a difference.

[mdmellott]

I was just thinking, perhaps a passive rotation of the front wheels turning may be normal while in 2WD but I'm not that familiar with the All-Mode 4WD transfer case clutch plates and gear engagement. If you can stop the wheels from turning by safely taking hold of the wheels then they are not actively engaged and this could be normal. If they are spinning fast then I wouldn't advise trying to grab hold of them.

[RBPathy]

Yes, while in 2Hi, on blocks, the front wheels will turn 'passively' but I can grab them with two hands and stop them from turning...so there's not much torque being applied. It just seems odd that they'd turn at all while in "2Hi" but maybe the "passive rotation" is really a thing??? and maybe it has to do with that All-Mode 4WD trans case.
I appreciate your feedback MD.

[Soliyou]

There is nothing wrong with your transfer case. This All-mode transfer case uses clutch packs and oil pressure to engage the front differential. When in 2wd mode, there is still very slight friction within the clutch packs (although the full pressure is not engaged) to cause the front drive shaft to spin. This can be thought of as parasitic drag.. it is too weak that you can stop it by hand at low speeds. I won't try to do it at high speeds.

In summary, your transfer case is working as it should. You probably want to give it fresh oil change to keep the clutch pack happy.

[RBPathy]

I appreciate that thank you Soliyou...

[Hawairish]

Echoing that the residual drag in 2H is normal.

Another culprit for vibration are the bushings in the front differential hangers. The hangers are what suspend the diff/axle from the subframe.

[RBPathy]

Appreciates yas...I'll look at those as well, thx