Read this thread:
https://www.hummerforums.com/forum/hummer-h2-8/most-common-problems-h2s-18186

 

Rust is easy fixed with a product sold in amazon I know is a 3M product but I can remember name now
even my Hummer from Florida (no salt on highways ) was showing patch of rust

My knowledge in the tranfer case options is very limited but Im almost sure the 4L acting the way you described is normal . Remember you shouldn't drive at high speeds in any other setting than 4H . Make sure to know the 4wd settings before you play with it . A bad selection may damage the TC
the link.provided by HOF is full of info
Most H2 here are way over 115k with minor issues

 

Also read the owners manual (you can even download it from the GM website if needed) and be aware of how to correctly operate the 4WD controls. The H2 if full time AWD and the controls look the same as on the regular trucks but must be used a little different.

 

The rust on the rear quarter is pretty common. It is caused by that rubber trim they use to fill the gap between the bumper and body. As the chassis shifts with the body it rubs the paint off and then you get the rust. I keep the flat part of the body where the rubber meets coated in grease and it has really helped any further damage from the salt and brine my truck sees. I also get it oiled every fall.If you let it go it will eventually travel up the side of the body and rot around the gas cap area. Very unsightly.

i have owned a few gm trucks from this era. I must say the h2's are pretty rock solid and the best gm product i have owned from the 2000's

Things to look for:

water markings around sunvisors- usually clogged drain tubes or marker lights- check rear markers as well

door panels - look for cracks around handles and map pockets- hard to find to replace and $$$

rear license plate tray- crappy engineering held in by 6 plastic studs- usually broken. Ive had to fix mine several times

mirrors- make sure they function is intended- especially 03-05- discontinued

exhaust mainfold- bolts- like all LQ's they like to snap the heads off- passenger manifold likes to crack

Also check if they have mounted a transmission by pass cooler. The trans fluid runs through the rad and if the rad lets go it will toast the trans.



Be patient and find the best truck you can afford

 

 

@madmayo . Good points .
Mostly the transmission aftermarket cooler mod . Will save a big headache
The transmission runs cold even while towing 4000 pounds @ 190 max in a 100° weather

 

welcome to the forums . i got my 04 H2 in houston than later moved down to TAMPA you can find some good deals around the tampa bay area but if i were you ill try to pick one up in texas , in florida lots of h2 owners had their H2 near or in salt water and do not have any underbody treatment at all and that my friend can bring some problems to you the new owner down the line . another thing to look for is to make sure you check all the lights up in the roof H2s leack water that goes in through the lights , inside the truck check the headliner if it looks like it has any stains near the front windshield its s sign that the previews owner did not took care of that and you may be able to use that at the dealer and get a few $$$ off the price , in my case the dealer took 2500$ off the price just cause of that , in tampa you get LOTS OF RAINN so you will deal with water alot ..... again welcome to the forums and hope you enjoy tampa ,florida can be fun at times .

 

One thing i forgot to mention. Was that when i was looking i stayed away from the air suspension and found one that had coils. I know that they ride better but these trucks are old and the air suspension can become an pain in the a$$.