Got a 72k 02/patherfinder but already rusting.??

[Bryan.g23]

I got a really good deal on 2002 pathfinder 72k on the dash, settled it for 3grand and that baby was mine. However it came from Texas, I am concerned how it got rusted so fast, I know they are notorious for that but still, plus I live in chicago were the salt from winter cause sink holes not pot holes lol so im worried on its effect on my SUV, 

 

Another concern is that it runs smooth and good, but when on 4wd auto, the rpms jump and my truck doesnt move, then I swtich it back to 2wd drive and I always hear a loud "clunk" doesnt sound good. I do want to flush the trans fluid but not sure if the trans would be trashed if I do. 

 

I'm glad I found this forum btw I ddo plan on keeping this bad boy for life! Will upload lots of pictures on future mods. So far ive only done ball joints, control arms and sway bar bushings. Tie rods and sway bars neck. Before I throw on lift and wheels spacers for some new tires.

[hawairish]

Welcome!

 

Texas is still a pretty big place...any idea where?  The gulf regions can be humid, not to mention prone to flooding, and there's something about that TX mud/clay.  Having lived in Chicago and seen the effects on a brand new car, you might want to consider some treatment options, even if that just means spraying some stuff underneath.  There are some particular rust spots that should be inspected, namely the strut towers and lower corners of the front fenders.

 

The All-Mode 4wd system I'm not familiar enough with, but a transfer case drain and refill is usually advised whenever any noise/shifting issues exist; at minimum, check the fluid level by opening the fill hole, and even stick a finger in to check the color.  The transfer case and transmission have separate fluid cavities, but both use ATF.  Neither need flushing; drain and refill generally fine.

[Slartibartfast]

Where/how bad is the rust? If it was a Texas car all its life and just moved to Chicago, I wouldn't be surprised if metal that's been exposed for a long time started rusting. Look into an oil undercoating. Keep a close eye on your strut towers, that's where the rust tends to get dangerous on these. Hopefully you can nip it in the bud.

Sounds like a problem with the transfer case, not the transmission. I don't think it's supposed to clunk, much less when going between 2x and auto (auto is only supposed to engage the clutches if it thinks the rear end is slipping, and I don't think it's supposed to clunk even then). Might be worth doing a drain/fill on the transfer and see what's on the magnet. The only way the transfer should stop power getting to the rear wheels is if it's in neutral (between 4HI and 4LO), and of course it shouldn't stop in neutral, or be trying to switch ranges at all when you go between 2H and auto. Something's not right, for sure.

 

I flushed the trans on my '93 at around 230k and it didn't hurt it a bit. I put one of the cooler hoses in a bucket, ran it until it quit spitting old fluid, added fresh fluid through the dipstick tube, and repeated until the fluid that came out looked like the fluid I was putting in (red instead of brown).

[RainGoat]

Coastal Texas plus 5 Hurricanes & 5 Tropical Storms since 2001. If it’s pervasive it may well have been flooded by saltwater in a hurricane storm surge.