Service
Like any vehicle, it does require maintenance, the Hummer has just a little more maintenance then a car or truck, and once you have learned what they are, it easy to do,  yourself, or trustworthy mechanic can do it.  Basically, what I have found different is it's geared hubs, something very few other vehicle will have. Oil changes, tire rotations, checking of  the belts, just the standard stuff.

I do my own basic maintenance, except for the engine oil changes, that is something I take to Jiffy Lube to do, that stuff is so black, it unreal (one drop goes a long way)  .After every outing I  make sure all my grease fittings get greased and check all fluid levels.  I am regularly under my truck checking for any signs of problems (don't ask how many time I have fallen asleep under the truck on my nice padded roll around creeper).

The Geared hubs are not so easy to check, two of them you can check the fluid levels without taking of the wheels, the other two are not as easy.  But with basic air tools, Air driven jack, and air ratchet or impact, removing the tires is not so bad. Beside, this makes it easy to clean out the mud from the rims and hubs.  Changing the gear oil and transmission fluid was easy and allows me to check to make sure no water is getting in the system. The transmission has a drain plug like the engine oil, making changing of the transmission filter and fluid easy.  They recommend that the hubs and axle assemblies are checked every 3,000 miles or 6 months, and change the engine oil.

Brakes, well the other day my rear brake caliper gave up on me, locked up big time, so while I was at it, I replaced the brake pads on the other side, and will be replacing both the pad and caliper as soon as UPS brings it by.  I have heard that the rear brakes are the hardest to replace, and now that I have done that, the front should be a snap.  I only had trouble betting one bolt loose, but once it was loose, the rest was easy.

Its always a good idea to keep a log of the services required and done to the Hummer,  I have been trying to keep the log here. Service Record  but it is a little out of date now.

Here is how the maintenance Operations reads:
 

I am sure this will look just about the same for any truck or car, maybe a little more frequent than most cars.  But for what I can put this truck through, it's worth the time maintaining it, and it give you a good feel on how well the truck is working.
 
 
Balancing the Tires ! Here we are getting the tires spin balanced! Most tire service center will not do "Hummer" wheels mainly because they are too big and heavy. So I had to take it to a real tire shop like this place. They did a GREAT job. At first I only thought that at 65 mph I was having a problem, but after they did they job (45 minutes) it rode so much better even at 35 mph. And was only $15 a tire if it was out of balance, otherwise no charge. 

Northwest Chassis Service, 14720 Kuykendahl, Houston Tx 77090, Ph 281-440-0107

 
Check out CCJ for more good information about balancing tires. http://www.ccjmagazine.com/balance.htm#intro

After a few months, I figured I better check out my wheel alignment, took it to Brake Check.  They did the alignment just fine, but for some reason I had the shakes again in the front.  Every thing looked just fine, no missing weights, or anything I could see, so I decided I will try out the Centramatic Wheel Balancers.  Click here for "Wheel Balancers"