Buying a Used Hummer and What to Look For. Gas vs. Diesel
Updated March 13, 2016
The 2006 model year was the last for the Hummer H1. In May of 2006 the president of AMG said "Unfortunately, in recent years, the production and actual retail sale of the Hummer H1 have fallen to a level between 200 and 300 vehicles per year. At that level of sales, the GM dealers tell us that with a vehicle that costs $145-150,000 each, it just becomes too difficult to find customers willing to pay. " Unless AMG and GM change their minds, the only way you will get an H1 will be to purchase a used one.
Because there are no more Hummer dealers and they aren't making new trucks you are going to have to purchase from an owner or a used car dealer. Hummers, and I mean H1's are now considered 'exotics'. There aren't many around and they are a very unique vehicle. The first owner paid a lot of money for one. Because of the poor economy the used market was really low after the tech crash around 2000. People bought used trucks cheap and couldn't afford the upkeep. This turned many nice trucks into expensive restoration projects. Because of this I wouldn't buy a truck site unseen unless it's from a seller that has a very good reputation. I wrote a whole article on one good example of a used 2002 offered for sale that looked fantastic but was in need of a lot of work.
The H1 is unique because technical changes were slipstreamed in constantly, not just at the beginning of a model year. This was due to the way government contracts to supply military trucks were written. The government wanted the newest and best fixes installed on the trucks as soon as possible. When setting your sights on a used H1 it's important to know what those changes were and when they were implemented. A comprehensive list of changes can be found on my web site (www.flashoffroad.com) in the Buying a Used Hummer section.
A Hummer H1 is a maintenance intensive truck. If you religiously keep up with it a used truck will be like new. There are many hummers out there that have hard miles on them and have been neglected with little or no maintenance. Make sure you know what you are getting. For instance, if you buy a model without CTIS, 4 speed transmission or the 2 fuel tanks its difficult and economically impractical to install these later. There have been so many changes throughout the years; hence it's important to know which features and improvements you want.
High mileage doesn't matter if the truck has been maintained because all the wear parts have probably been replaced. A newer truck that hasn't been maintained could cost you far more. The biggest weakness of the Hummer is it's front end. The trucks go through idler arms, pitman arms and steering gears. Problems with bent wheels and out of round tires and out of spec aftermarket wheels exacerbate the problem.
I always get a laugh when someone says that the truck was never off the road. The fact is that 'on road' miles are by far much worse for a Hummer. Driving off road at 3 to 5 mph puts little or no strain on the drivetrain. Driving this unaerodynamic truck on the highway at 60 to 70 mph is where you use the horsepower and strain the components. The Hummer was designed to run on unimproved roads and trails; not necessarily on the highway. I never drive my Hummer faster than 67mph. Most of the owners I've met who off-road their trucks on a regular basis take much better care of their trucks and are more aware of the care and maintenance they require. Owners who bought the trucks to drive as street queens consider them the same as any other car and drive and maintain them as such. For instance, I've emptied many transfercases full of brown burnt oil because the truck was driven at 80 and 85 mph on a regular basis.
The $100,000 question is - What are used Hummers going for? If you're looking to buy or sell an H1 you will find many for sale on ebay and Autotrader.
Here's a couple of important facts for buyers and sellers. Buyers of used Hummers are looking to finance them and therefore are limited in how much they can borrow to purchase the truck. Most will finance through a bank or a credit union who will often times only loan off of NADA Low Retail which is a pretty low value. Depending on the buyer's credit some will loan off of Kelly Bluebook which is higher.
The following is a condensed synopsis of the different model years and some of the factors to consider when purchasing.
The first civilian hummer rolled off the production line in late 1992. So the 92 & 93 models are kind of in their own category. They are the closest models to the military HMMWV. The seats are not adjustable, have plastic covers and the batteries are under the seat inside the truck. There isn't any sound insulation so the trucks are very noisy. The drive train consists of a 3 speed transmission; the mechanical bulletproof 3L80. It does not have overdrive which makes it pretty difficult driving on the highway over 55. They also have a 6.2 liter diesel engine that has been called under-powered. The trucks all have 25 gallon fuel tanks. On the other hand the trucks are lighter. The nice thing about these trucks is that they are less complicated and easier to work on because do not have computer controls. Their A/C blows cold because they use R12. These trucks are a favorite of the hard core off roaders. These trucks came with 16.5" two piece steel wheels and Goodyear MT tires.
1994 models got an entire drive train change with the NA (naturally aspirated) 6.5 liter diesel engine and a GM 4 speed 4L80-e transmission. The new 4 speed transmission really brings the engine rpm down on the highway saving fuel, wear and tear and noise. The 6.5 NA engine is still very under powered compared to a turbo diesel. At high altitudes they run out of power on the road and off. They also relocated the batteries, changed the HVAC design, made body and interior changes as well as adding adjustable seats. The new HVAC system turned out to be under powered and prone to heater core problems.
The biggest thing in 95 was the introduction of the 350 cubic inch gas powered engine. Many customers were apprehensive about owning a diesel so AMG created the gas model. Aside from having on road performance as poor as the NA diesel the fuel tank only held 23 gallons which isn't much when you're getting 7 to 11 mpg. The 95 incorporated many of the base improvements and creature comforts found through the 2003 model year such as the interior and body.
The 1996 was a major step because it was the first year of the turbo diesel which finally brought the truck into the realm of great on-road and off-road performance. All the 96 trucks came equipped with 2 fuel tanks for a total of 42 gallons. This was a real boon for the gas powered trucks. Unfortunately, it was the last year gas trucks were produced. A major problem cropped up with the turbo diesels in 1996 into the 2000 model years. They are at risk for a cracked engine block due to a GM design flaw. AMG replaced many engines under warranty. If you buy a used turbo diesel truck it would be a big plus if it's engine was already replaced.
1997 was a year that brought many major improvements to creature comforts. The truck was outfitted with decent sound insulation and the Monsoon stereo was introduced. The turbo diesel was upgraded for better cooling and a little more power. Many items were slipstreamed into production this year so there is an important difference between 1997 and 1997.5.
The most important change in 1997.5 was a complete change in the heating and air conditioning. The heating / AC system introduced in 1994 was a poor design and didn't perform well. There were numerous changes made to this system over the years that didn't solve the problems. Finally AMG stopped producing replacements and upgraded all the defective in-warranty trucks. The heater cores are almost impossible to repair and the upgrade cost around $3000.
How do you know if your truck has the upgraded system? The easiest way to know is by looking at the controls. The older controls will have an additional 2 buttons on the panel. One for recirculate and one for A/C. The photo is the new style control in my 1998. The upgraded system uses a vacuum controlled heater valve while the old system uses an electrical one. This is the valve that controls the flow of hot coolant to the heater cores in the truck. When the airconditioning is on the coolant is shut off. This article shows how to identify the newer valve. This article shows the older electric valve. Another way to know for sure is to pull the HVAC control head out of the dash. The new system is vacuum controled so you will see a bunch of small diameter colored tubes coming out the back.
1998 is considered by many to be the quintessential year because it has all the improvements that were begun in 1997 and is the last year before Hummers were equipped with ABS and a new TT4 traction control system (which many off-roaders don't like) that caused the Torsen I differential.to be replaced with a Torsen II. The method for camber adjustment was changed to cams instead of the labor intensive shim system. This truck is quieter then any of the previous Hummers and has the axle ratio that AMG is now using in all the Hummers.
1999 was a transition year. The NA diesel was dropped. Due to the introduction of ABS and TT4. The NTSB mandated that class III trucks have ABS. It was believed that the ABS system wouldn't work with the Torsen I differential which up to now provided the exceptional traction the Hummer was known for. This is why AMG had to go to electronic traction control (TT4). Because it was the first year for TT4, the system is not as good as the later models. The truck as a whole, it's creature comforts, sound insulation and interior are perfected. This would be a great year for a mostly on road truck or a good candidate for add-on lockers.
2000 - 2002 are pretty much the same truck as the 1999 except for some minor interior changes.The TT4 is improved. AMG introduced 16.5" and 17" aluminum wheels although by 2002 all 16.5" wheels were discontinued. These are great on road trucks and once again good candidates for lockers. They did increase the differential bias ratio on the 2002 trucks which will allow you to BTM them. In 2000 the factory produced 39 slantback models which are relatively rare. In 2002 the factory produced 65 burnt orange 10th anniversary model wagons with tan interiors.
2003's have an Eaton electrical rear locker which goes a long way towards making the truck as good off road as the earlier trucks with the torsen I differentials.
2004's have a Brand New Interior and an upgraded engine called the 'Optimizer' which has 10 more hp. Due to new government smog regulations AMG went to an engine computer built by Caterpillar. Otherwise the engine is the same. Optional Eaton front and rear lockers are available which make this the best stock truck yet. AMG does sell the Eaton lockers to upgrade older models. You also have the option of aftermarket Auburn electronic or an ARB locker. There is a big step between 2001 and 2004 as far as noise level and driver comfort goes.
NOTE: AMG skipped the 2005 Model year for H1's.
The 2006 Alpha is an order of magnitude better both on road and off road. Just about everything under the truck is new. According to AMG the only parts that are the same as a 2004 are the control arms. The suspension uses all the components from the 12,100 GVW upgrade which includes larger disk brakes, heavier half shafts, springs and sway bars. The whole steering system has been redesigned using a heftier Sheppard steering gear box, stronger components and changes in geometry. The whole drive train is different due to the addition of the Duramax diesel and Allison transmission. Because this combination of engine/ transmission is longer, the transfercase is pushed further towards the rear. This necessitates a longer front drive shaft which is a new design using double cardon U joints. In order to meet DOT requirements the shape of the fuel tanks had to be changed. When the tanks were redesigned, engineers at AMG took advantage of the extra 2" space that resulted from the lifted body to increase the total fuel capacity to 51 gallons. The transfercase is the same NP 242 which was strengthened to take the increased torque from the new engine. The geared hubs now have helical cut gears to reduce noise. The price of the Alpha includes all scheduled maintenance for the warranty period.
The downside to an Alpha is the price and it's uniqueness in respect to parts availability. You can spend anywhere from $131,000 to $145,000 on a new Alpha not including tax. The quoted price for an extended warranty is $17,000. Since the Alpha is a one model year vehicle and the majority of it's parts are unique you will have difficulty getting parts from anywhere other than the factory.
Later on in 2006 there was a 'wave 2' release. I know that these trucks come with one color upholstery.
Gas Vs. Diesel
AM General produced H1's with gas engines in 1995 and 1996. All the diesels prior to 1996 are N/A (naturally aspirated) diesels as opposed to turbo diesels which were introduced in 1996. The drive train on all of the 95 and newer trucks is pretty much the same until 1998 when they changed the differential ratio. I've owned 3 Hummers a 95 gas wagon a 96 Turbo Diesel wagon and I presently own a 1998 Turbo Diesel wagon.
The 5.7L (350 cu. in.) TBI (throttle body injection) gas engine installed by AMG is the 1995 GM LO5 version, GM Assembly no. 10205700 with a 3 page list of AMG add/ delete components to facilitate installation in the Hummer. The engine falls into GM's Medium Duty Truck/ Van gasoline engine classification. When the first gas engine was installed in 1995 the transfercase had to be beefed up because the gas engines produced a greater torque spike then the 6.2L and 6.5L N/A diesel engines of the day.
In 1995 my only choices were gas or N/A diesel. Why did I purchase a gas truck? I didn't know anything about diesels and wanted something I knew how to work on. Don't forget, just about all 4wd's made are gas powered. I felt that I could get fuel anywhere even out on the trail in remote areas where the chance of a diesel truck coming along is about zero. That was true in 1995 but not true in 2006. I was recently in Colorado and there were diesel pickups on the trails. The 350 Chevy small block is the most common engine ever built and can be repaired anywhere in the country. If the engine doesn't last as long as a diesel it can be replaced dirt cheap. There are more add on parts made for this engine than any other engine in existence. Its quieter and starts up with no problem in the coldest weather. The gas truck can be sound insulated much easier then a diesel. The fuel injection system on the gas adjusts the correct mixture at any altitude, while the NA diesel has a tendency to smoke at high altitudes. The turbo diesel runs great at high altitude.
After driving both, there isn't much difference between the off road performance of a gas vs an N/A diesel. Shortly after I bought my new gas truck I had the opportunity to go to AMG and compare one of their N/A diesel trucks to my gas on their obstacle course. What I found is that each engine has it's own distinct feel. A gas truck will allow much more compression engine braking then a diesel because of inherent design differences. This made steep descents much easier to control which is very important when 4 wheeling. The diesel engine is harder to stall then a gas engine due to the high torque at low RPM's a diesel operates at. I took my gas truck to Colorado and Moab Utah a number of times and had no problem going anywhere I wanted. I did observe that the gas and N/A diesels will run out of power climbing steep hills or pulling stuck vehicles in the mountains at high altitude.
The negatives about a gas powered Hummer are: You can only ford through 24" of water unlike a diesel which can go to 30" because the diesel starter is waterproof. A gas engine has a high voltage spark ignition that can get wet and stall while the diesel does not. The gas engine produces much more heat that rises up into the cabin. A gas engine produces its power at 2700 RPM so it's necessary to put your foot down a little more when going over obstacles. The diesel truck achieves it's peak torque at 1700 rpm. That means that when pulling or climbing at peak torque the diesel truck is moving at just over half of the speed of the gas truck which allows for better control.
My gas truck got about 4 mpg off the road in the Colorado mountains while the more efficient diesel can get 10 - 12 mpg. All Hummer H1's built before 1996 have one fuel tank. The tank on a gas truck holds 23 gallons while the diesel tanks hold 25. The gas trucks hold less because the fuel pump is in the tank and there has to be room for vapor expansion. Having a 23 gallon tank getting 4 to 7 mpg motivated me to look into installing an auxiliary tank. A couple companies made diesel tanks that fit in the fender well but I discovered that gasoline is much more volatile then diesel fuel so by law you can't mount a gasoline tank outside the frame rails. In 96 AMG added an additional 17 gallon tank to all their H1's. I researched adding the auxiliary tank to my 95 but It required changing the exhaust, trailer hitch, cutting the body for the second fuel filler and adding all the electrics to handle 2 tanks. It cost way more money then it was worth so I ended up carrying a 5 gallon jerry can.
The on-road performance of a gas truck and the N/A diesel is what really leaves a lot to be desired. The gas and the N/A diesel trucks might go 0 to 60 in 45 seconds. You can't pass on the highway and your maximum speed going up hill on high mountain passes is barely 40. When I had my 95 gas wagon I examined ways to increase the performance of the stock engine. The objective was torque at low Rpm's. Most modifications to gas engines increase the horse power at high rpm's. After experimenting with a program chip which didn't do anything I found that the solution to the problem is to install a supercharger. A supercharger would allow me to keep the truck stock and increase the horsepower from 180 to almost 300 and do it at low Rpm's. Whipple made a kit that consisted of a new intake manifold, the supercharger, a new air filter assembly, pulley, fuel pump and programming chip. It requires premium fuel. The unit was around $5000 and a good installation is $1,800 unless you do it yourself. The 350 block used in the Hummer is a heavy truck unit with 4 bolt mains and should take the added stress with no problem. I drove a Whipple charged truck and clocked it 0 to 60 in 13.5 seconds. It drives around town and moves in and out of traffic like a nimble Jeep. The owner has had it installed for years now with no problems. There were only about 20 of these Hummer supercharger kits sold since 1995 and they are no longer made, although you can occasionally pick them up used.
After a couple of years of agonizing about fuel capacity, mileage and power I traded up to a 96 Turbo Diesel. I had to eat my words. One of the best moves AMG made was to equip the Hummer with a Turbo Diesel. I never owned a diesel vehicle until I got my 96 wagon. It's now my opinion that a 8000 lb truck really needs a turbo diesel. The major difference is gobs of torque at low rpm's. My 96 got 11.5 in the city and 15 on the road going under 67 with the air off. The truck hardly uses any fuel when off the road. It just idles along putting out all kinds of torque at 1200 rpm. At high altitudes the turbo runs very clean and puts out power to spare. The TD is much better on the road because of it's increased power. My 96 could maintain 55 mph going over Loveland pass in Colorado. My 95 gas truck could barely go 40. I got high centered in the mountains and strapped up to an NA diesel. He just plain ran out of power trying to pull me out. His tires weren't spinning and his truck wasn't moving, just a lot of black smoke.
It turns out that diesel fuel is pretty easy to find. With all the diesel Semi's, pickup's, RV's and farm equipment, pumps are available everywhere. The diesel doesn't smell because modern diesels burn clean. The only thing I can say is they are harder to start when it's cold and it was a lot harder to sound insulate then the gas. All the diesel Hummers come with block heaters so you can plug them in when it gets really cold. I also recommend using Stanadyne performance fuel additive in the winter and occasionally in the summer to clean and lubricate the injector pump.
I now have a 1998 Turbo Diesel Wagon. The main difference between the 96 and 98 is the engine. In 1997 GM made changes to the Turbo Diesel that improved the cooling allowing them to get another 40 ft. lbs of torque. They also geared the diffs a little higher so theoretically you should be getting better mileage on the road. This wasn't true for me. The 97.5's and the 98's are much better sound insulated right from the factory. They have cushioned headliners and monsoon music systems.
The 97.5's and up come with a much better heater and air conditioner. This is a major consideration because pre 97.5 HVAC parts have been discontinued. The older systems have a tendency to develop leaky heater cores and were not built to be repaired. You are forced to upgrade to the new system which will cost you between 3 and 4 thousand installed. Of course the new system works great.
The 98 has been labeled the best truck AMG has made to date (aside from the new 06 Duramax Alpha). After 98 the government mandated ABS on all the trucks. This forced Hummer to change to another type of Torsen differential and go to TT4 for traction control. While this is another subject the TT4 is not nearly as good for heavy duty off roading like rock crawling. The TT4 is great if you use the truck in the snow and on loose rock and soil.
Inspecting a Used Truck
See if the owner has a traceable maintenance history showing what was replaced and when.
Make sure the paperwork is in order. You want a clean title and check for liens. Check with Carfax to see if there is anything wrong with the title or mileage. This will tell you if the car has a salvage title or if the claimed mileage doesn't agree with mileage reported to Carfax.
Does the truck have aftermarket wheels or oversized tires? There are only two brands of wheels that have the correct offset and weight capacity for a Hummer H1. AMG factory wheels (made by Hutchenson) and GT/ Cepek Wheels. Incorrect wheels can be dangerous because they change the steering geometry and alignment which causes stress on the suspension that can lead to premature wear and failure of critical parts. Don't forget that a Hummer weighs 7 to 8000 lbs. Wheels with lesser backset stick out beyond the body causing road dirt to be thrown all over the side of the truck. If I see a truck with aftermarket non Hummer wheels I immediately discount it by 5000.00 which is what it costs to put a new set of wheels and tires on the truck.
The other problem with aftermarket wheels is that they don't support the cti system the right way. They usually don't have the correct fittings at the rim for the air line. I always look to see if the cti system is maintained and all there. I've seen a number of owners abandon the system because the pump has gone bad. A new pump can cost well over 1000.00.
If the truck has 16.5" wheels available tires are scarce. Pretty much the only tires you can get in 16.5 are the Interco Super Swamper type tires and the noisy absolutly terrible military MT's. Goodyear doesn't make 16.5" or 17" GSA's anymore and MT/R's are only available in 17's. 17" Tire availability is what drove many owners to the GT Cepek wheels (This is how I originally got into the wheel business) and AMG to all 17" wheels. If you are using 16.5" wheels you better make sure you have a spare because you will never find a 16.5" Hummer tire in stock.
Before you do anything DO THIS. The truck has to be dead ass cold. This means the truck hasn't been started for 8 to 10 hours or more. Open the hood and remove the radiator cap just to make sure there isn't any pressure in the cooling system. Do the following for sure on 1996 to 2001 turbo diesels. It can't hurt to do this on all trucks. Start the truck up and let it idle for a two minutes and shut it off. Watch to see if smoke and what color comes out of the exhaust pipe when the truck starts. The truck should start immediately once the glow plugs cycle. If it cranks hard before starting there is a problem. Next, remove the radiator cap and see of there is pressure. On a cold engine there shouldn't be any. If there is (you will hear a quiet 'whoosh' or a light 'pop') it could indicate a cracked block or blown head gasket when combustion gas gets into the coolant system through a crack. See the article on cracked blocks on Flashoffroad.com. Once the engine is completely warmed up crack open the coolant air bleeder. If foaming coolant comes out you have a problem. When you shut the truck off and hear a 'clunk' you have a vibration dampener going bad.
Don't forget to check the obvious. Check the fluid levels including the engine oil, antifreeze (engine cold), power steering, brake and automatic transmission (engine hot and running) Bad transmission fluid smells burnt and is brown instead of red. If you can; check the fluid in the transfercase which typically runs very hot when a truck has been driven at excessive speeds. Remove the transfercase fill plug. If oil starts pouring out you have a leak in the cooling loop otherwise called the "vampire".
Check the battery water if it's the kind that needs fluid. See if there is any oil visible under the truck or on the street.
Check for body damage. Take a look at the undercarriage and see if it is bent up and touching the exhaust. This happens frequently when you off road. Look at the rocker panels and see how bad they are scarred up. The rockers oftern get bent up at the front edge. Check the body for rust at seams in the roof and where the wagon body meets the lower body. It is normal to see rust where the aluminum body meets the steel roof. There often is corrosion in the aluminum around the marker lights. Pull the carpet up over the wheel wells on a wagon and look for rust on the inner seam. The Hummer doors and wagon top are steel, not aluminum. Look for bubbling paint around the tail lights. Look for paint over spray which would indicate body work. Look for cracked or broken glass or plastic parts.
If the truck has a soft top check it's condition. Is it the original top? Make sure it has an original factory top. Look for fading, cracks or tears. Is the rear window scratched or marred?
If the truck is a pickup check the shape of the bed, is there a bed liner, is there a tonneau cover, does the tonneau cover have a support bar, does the tailgate function normally?
If there's a spare is it the correct size, does it match and is it in good shape?
If the truck has a winch make sure the winch control cable is with the truck and check if the winch works.
Make sure the jack is with the truck. Often times it's stowed below the rear right seat.
Check the operation of all the locks, the keyless remote and the horn.
Check all the gauges and make sure they work.
Try out the radio / cd and make sure it works.
See if the power mirrors and power windows work. The power window regulators (motors) are expensive and difficult to replace. The windows may be slow to rise and lower due to sun film that has been applied to the glass. Check out all the lights and turn signals.
I think one of the best indicators of a truck's condition are the tires. Uneven tire wear indicates problems with alignment, front end parts, wheel balance and shocks. Check the tire pressure and make sure the central tire inflation system works. Run the pump on the front, rear and both tires. Depending on the tires the pressure should be 30 to 37 psi cold. I have a tread depth gauge that I use to measue the inner, outer and center tread.
Hummers go through suspension parts like most cars go through brakes. Idler arms, pitman arms, ball joints, tie rod ends are all items that seem to get replaced frequently. With the truck running turn the steering wheel. If you can turn the wheel 2 or more inches back and forth and the front tires don't move you probably have a bad pitman arm. When you turn the wheels all the way to the right and all the way to the left and they turn easier in one direction you probably have an issue with the steering gear. A steering wheel that isn't level indicates an alignment problem.
Look at the geared hubs. If you see oil dripping or a fan spray of oil on the inside of the tire you have a hub seal leak. If the CTI system won't hold air you could have a leaking hub seal.
Look at the half shafts and see of any of the rubber boots are ripped. Make sure there aren't any wet spots where the half shafts enter the differentials and hubs. If the calipers are wet it may be diff oil leaking.
Look at the truck on a flat surface and see if it sits level. If the truck isn't sitting level you have sagging springs. Closely examine the springs and look for cracks in the coils indicating a broken spring.
The truck should stop straight and the brake pedal should be firm and not pulse. Pulsing brakes indicate a warped rotor. Soft brakes indicate air in the line. Check the brake pads for wear. Check the rotors for discoloration and deep scratches.
Test the parking brake. Put the truck in gear and make sure the parking brake holds the truck back. Make sure the brake releases. The parking brake is incorporated in the rear calipers and can be expensive to fix.
With your foot on the brake put the truck into drive then shift to reverse. Do this a few times. See if you hear much of a clunking sound. This will tell you how much free play there is in the drive train. It could be a stretched transfercase chain, bad hub, bad diff etc. My truck clunks because I have a Detroit locker in the rear. It's normal for a truck to clunk when shifting from D to R and back due to the normal shifting of the automatic transmission. You really have to know what to listen for. If you hear anything metallic you probably have a problem.
Drive the truck around town and on the highway. Make sure the transmission shifts into all 4 gears.
See if the truck sways around corners. This is an indication of worn shocks. Most owners don't realize that their shocks are worn due to the stiffness of the Hummer's springs.
Take it up to 70mph and see if it shakes. Many trucks have vibration problems due to bent wheels, out of round tires, unbalanced tires or worn suspension parts. If you feel a vibration under the drivers feet it could be a bad front drive shaft which can also give you a burnt rubber smell. See if the truck pulls to one side or the other. This could be a brake problem or alignment. Alignments are expensive.
This is a good time to check the cruise control and the dual fuel tank selector switch (on trucks 1995 and up).
See if the transfercase will shift into 4H and 4L. This is best done on a dirt or a gravel road, not on a hard surface. If you have a problem getting the truck out of lock put it in reverse for about 5 feet, shift into N and shift the transfercase.
Drive the truck in a very slow tight turn in both directions. See if the tires are rubbing on the hood or suspension. This could indicate over sized tires or sagging springs. If you hear any creaking noises it could be loose front body mounts.
Drive long enough to completely warm up the truck. Make sure that the truck's engine temperature is in the normal range. Trucks with a gauge should read almost 200. Voltage should read over 13 to 14 when the truck is running.
Test the heat and the A/C making sure the blower blows on all speeds. Don't forget to check the aux air hi and low blower for heat and cooling.
Most of the trucks were delivered with the following items:
- Roadside reflector set which has 3 triangular reflectors that are required for a class III vehicle.
- Yellow coiled extension air hose for the cti pump
- Owners Manual
- Jack and lug nut wrench
- 3/4 and 5/8 wrenches
- Ignition key
- Glove box key
In many cases you are purchasing a truck that's 15 or more years old so realistically you can't expect it to be perfect. The chances of finding a truck that has a perfect body or an untouched interior are pretty remote so take some of this advice with a grain of salt. What you should come away with is enough knowledge to know what you're getting.
Comments and Notes on What to Look for in a Used Truck, How to Drive and What Minimum Spare Parts to Have on Hand.
I would get a spare fuel pump, fuel filter, spare tire and belts. I like a 48" highlift jack. For heavier off roading I would have a complete tie rod with both ends and a set of halfshafts. Also keep spare fluids like automatic transmission fluid, oil and brake fluid. Keep up with the maintenance. If I were to do a lot of highway driving I would look at 96 and up. 96 is the first year all the trucks had the aux fuel tank. I would also go with a diesel, preferably a turbo. I had a 95 gas truck. The tank only holds 23 gal and you will get 7 to 11 mpg. Off the road as low as 4. The diesel also runs cooler. My next truck was a 96 td wagon which was a great truck. If you want the truck to last don't run it past 2400 rpm which is around 65 mph. Any faster and you will burn the transfercase oil and put more stress on the truck then it was built for. Driving under 65 you will get 13 to 15 miles per gal of diesel too. Here's a complete article detailing spares and tools.
All the pre 97.5's have the old A/C system that is prone to leak so test it out. AMG doesn't sell parts for it anymore so unless you can fix it you will have to upgrade it for around 3000. I think one of the best indicators of a truck's condition is the tires. Hummers go through suspension parts like most cars go through tires and brakes. Idler arms, pitman arms, ball joints, tie rod ends and of course brakes are all items that seem to get replaced frequently. With the truck running turn the steering wheel. If you can turn the wheel 1 or more inches back and forth and the front tires don't move you probably have a bad pitman arm. When the turn the wheels all the way to the right and all the way to the left and they turn easier in one direction you probably have an issue with the steering gear. If the steering wheel isn't level when you are traveling straight you may have a bad idler arm and or alignment problem.
Correctly aligning a pre 97.5 truck can take 6 to 8 hours because you have to take apart the upper A arm's to add and remove shims. This can cost. Check to see if the truck is sitting at the correct height. This will tell you if the springs are good. Check the article on this web site on how to change springs.
Money Transaction Tips and Fraud:
1. Be aware that *some* banks allow a stop payment to be placed on a cashiers check, so when you talk to the bank be sure to ask if that is possible. If it is, don't take the check unless you can cash it before the buyer leaves with the vehicle.
2. To verify the check, do not call any phone number listed on the check. Use a directory to get the number to call. This foils any chance of a call intercept with someone pretending to be at the bank when they are not. It also proves that the bank EXISTS - and yes, I've gotten cashiers checks from non-existent banks!
3. Call a different branch than the one issuing the check, if possible. This minimizes the chance that a 'buddy' at the branch is covering for fraudulent activity. May not be possible if it's a bank in a small town, but try it anyway.
4. Ask to see the buyers drivers license and note the name and number on it. LOOK at the picture! If they ask why you want it, explain that until they register the vehicle YOU would be contacted if something happens (like an accident) and you want to know to whom to refer the police/sheriff/highway patrol. Better yet, photocopy the license or take a picture of it.
5. If everything seems kosher, take a picture of your buyer holding the cashiers check while standing in front of the vehicle. That proves their identity, their possession of the check, and their connection to the vehicle. It will aid in prosecution should it ever be necessary, and makes it impossible for them to claim they weren't involved. I've had people RUN away when requested to do this - of course I had already snapped one or more pictures of them.
Remember, thieves HATE cameras. Buy a disposable one for this purpose and USE it. You can also take a picture of the vehicle they arrive in - including the license plate, of course - and anyone who comes with them, etc. An honest person might think you're a little strange, but a thief will find an excuse to leave in a hurry.