So just how durable is the 97-02 Expy's 4WD system?

[97ExpGuy]

I don't have a certain question pertaining to the thread title but I am curious to know and read other members' opinions on the subject. I'm especially curious about the durability front IFS.

[bnovak]

the 8.8 IFS should handle 33" tires no problem, but anything bigger than that and it might be pushing it. It's based around the ring & pinion gear that is in the BACK of the ford explorer, but has CV's instead of straight axles, so you loose strength there (and in the bearing assemblies.)

The Borg-Warner transfer cases are pretty much bomb-proof with anything under 35" tires also. Just change the fluids regularily, but take note that it actually requires a different type of MERCON ATF than the tranny does. The book DOES NOT STATE this but if you ask a ford dealer or oil change place, it is listed as different (I think it's Mercon 5 versus regular mercon 4)

The rear end should be a 10.25 which is just huge. Not as big as a diesel dually, but pretty friggin close. I used this axle on my last rock crawler with 42" tires and never broke anything, so it's definently strong. It just hangs down a long way.

It all depends on what you are going to do though. Lift it and run rocks? Or just use it in 4wd in the snow. Different applications, and you'll get different answers.

[Omahastro1]

The front axle is an 8.8 which is pretty good for normal 4x4 use. I beleive the rear axle is a 8.8 in early models 97, 98 ? 99 are a 9 3/4" in the rear, pretty strong, but needs the fluid changed regularly. I change mine every 30,000 miles. If it has limited slip it needs a modifier added which is true on most LSD's. The transfer case is pretty strong but the shift motor is noted for going out on them. Mine is not working right now. The automatic 4 wheel drive uses clutches in the transfer case. This can burn fluid pretty quickly, so I use Mobile one in the transfer case. The transmition seem pretty good but here again are fluid dependant. Need to change the fluid and filter every 30,000 miles. This is a 6000 pound truck I enjoy driving mine but I wouldn't go into uncharted territory and get to crazy with it.

[97ExpGuy]

Thanks for the info. I hardly use the A4WD option. If I do use the system, I got straight to 4WDH. I always thought that auto option wold put extra wear on everything since its a constant on/off. Anyhow, my thinking is that in a few years I'll be buying a new vehicle and this one will remain as the bad weather/utility/hunting rig that may have to see moderate off road duty. That's why I asked.