Drivetrain problems..

[nicktheninja27]

I have a 99 Pathy, I was driving it the other day I put it into reverse and heard a grinding and crunching noise. It sounded as if I had back into/over something metal. I stopped, looked and didn't see anything. then tried to put it in drive,it didn't want to go forward. i had to rev it up to 2000 before the truck would move forward and had a ton of resistance, I tried to use reverse, it wouldn't move at all until I hit 4000, then it sounds like something breaks loose, the tires squeal, the truck lurches and flies backwards, while continuously making a grinding noise. I checked the brakes and the wheel bearings, both of which are fine. so now I'm left to assume that the issue is in the differential. Any ideas?

[atraudes]

Sounds like a bad transmission, right offhand. A transmission shop could probably tell you really quickly. Do you have 4WD? If so, it could also be the transfer case.

A few things you can try (while in 2WD, if applicable):

- Jack the rear up and put the rear axle on stands. See if you can turn the wheels by hand. If both of the wheels are off the ground, the parking brake is off, and the transmission is in neutral, the wheels should turn fairly easily. If they do, that means the brakes, axle, differential, and drive shaft are all working as expected (and will let you hear if anything's clanking around, and where). If that works, I'd say it's definitely your transmission or transfer case.
- If they don't turn, disconnect the driveshaft. This can be tricky as you may throw off the balancing and you'll get vibrations while driving. But, doing so will let you see if the driveshaft or transmission are interfering at all. Once it's disconnected, you can start the car, put it in drive and see if the output shaft on the transmission turns or not, too.

I wouldn't personally attempt the second suggestion since I wouldn't be up for that kind of adventure on my daily driver, but it's food for thought.

Good luck!

[nicktheninja27]

How do you disconnect the driveshaft?

[atraudes]

No idea; haven't done it myself. The FSM has some words on the matter in the Removal and Installation section, though:

http://www.nicoclub.com/FSM/Pathfinder/ ... der/pd.pdf

Try getting in touch with fleurvs and/or donald too. I'm pretty sure they've done it before, albeit on 01's.

fleurys-u158666.html
donald-u176497.html

[nicktheninja27]

I started it today. The issue with it not wanting to move is gone now. But now there is a loud noise in park and neutral. It kinda sounds like a fan that's spinning really really fast. And it's coming from the front end underneath. Transfer case or transmission?