Drivetrain Problems

[Nissanman]

Alright everyone, so I've got a problem that I really hope someone can help me with!

 

I've got a 91 pathfinder and lately I've been hearing a periodic vibration comming from the front end, only when it's about -20 or colder and only within the first 15 minutes of driving. Just recently, after switching out of 4wd, a "roar" started comming from the front end. I quickly pulled over and in doing so, the roar subsided and the vehicle jerked to a stop, as if something in the driveline was catching and resisting wheel rotation.

Sometimes, especially when it's really cold (-25 or -30 celcius), it feels like there is some kind of driveline resistance. If I step on the clutch and let it coast, the vehicle slows down much quicker than it should. Upon starting up I have to be in 4wd or else the rear just spins and the vehicle doesn't really move (this is on packed snow covered roads.) The breaks are not very old so I'm sure they're fine.

 

If anyone has any ideas I would really appreciate it!!

 

Cheers.

[Kittamaru]

Nissanman, honest question:

 

Did you remember to back up when you disengaged 4x4? If not, your front drivetrain is still engaged but your hubs are free running - auto hubs sometimes don't unlock right away which would possibly explain the noise.

 

Mine's an automatic though so I don't know if it'sany different for you.

[GrimGreg]

As Kit tried to explain, with the auto hubs, even if you shift into 2wd at the T-case, the hubs remain locked in until you change direction (ie reverse), the manual says 3 feet, but mine will usually let go in about half that. While the hubs are still engaged your front drive axels and driveline is all still turning with your wheels. Since your front wheels are trying to turn all that it causes drag and makes your truck sluggish, drive like that to fast or for to long and you are going to probably cause undue wear to your front drive components, which might have already happened giving you your noise(s).