If any of your customers enjoy taking their 4x4 vehicles driving in the hills, or even just pretending they do, you’ve probably realized that these vehicles need much more care and attention than even the severe-duty maintenance section in the owners’ manuals recommends.
Jacked up 4x4s that regularly go hunting, camping or just for rides in the bush or sand need to be inspected and maintained differently than the 4x4s that mostly venture around cities and towns (the ones that seem to eat brake pads and air filters). And there’s no great secret involved in servicing serious 4x4 vehicles, it’s just a matter of knowing what to look for and inspect on certain types of vehicles and then fixing those vehicles correctly when problems arise. True, that does come with experience, but it’s nothing you can’t handle – in fact, there are more than a few quick tips available to help you keep 4x4 vehicles running well no matter what the owners do with them.
In all honesty, most owners of 4x4 vehicles that go far off the beaten path really don’t want their vehicles breaking down or experiencing a critical system failure when there’s no help around (getting stuck is something else entirely) so servicing them right and identifying potential problems is critical and can often be profitable.
Here are some quick tips for keeping 4x4 trucks ready for hunting season, camping trips or spontaneous rides in the hills and back out again, keeping the work profitable and keeping headaches to a minimum. So if a customer’s vehicle does get stuck off road it won’t be because of something preventable.
Some basic checks first
Typically when servicing a 4x4 vehicle, carefully road testing it for problems is a wise first step – which seems obvious, but it’s worth repeating because it can save so much time and aggravation.
In fact, it may help to establish a regular, standardized test drive route that you always use, one that goes over various road surfaces, at various speeds, with various turns so that it’s easier to notice anything unusual on the drive – and also so people will know where to look for you if you break down. One car and truck manufacturer actually recommends that their dealer techs use a standardized test drive route with as few left turns as possible, since left turns tend to take longer to make and they’re also more likely to cause accidents. This may or may not work for you, but it’s something to keep in mind if you do decide to develop a regular test route.
No matter where the road test is performed, it should start with a walk-around inspection, including checking ride height (just quickly checking that it’s equal height from side to side), tire inflation and tread (in other words, see if there’s an obvious tire or wheel problem on the vehicle), testing the shock absorbers by “bouncing” the corner of the vehicle to find out if the vehicle comes to rest within a few oscillations, and also listening for noises that shouldn’t be there (like squeaking or grinding) while bouncing the suspension. This step can really save time on these vehicles. One customer recently used his Sequoia to haul a load of gravel – it’s a great truck but not the right one for that job – and the rear shock absorber failed shortly afterwards. This problem area was easily noticed and diagnosed by bouncing the vehicle, finding something unusual and then inspecting the shock absorber itself (it was obviously leaking). Fortunately replacing it is an easy job, simply involving two bolts and some wiggling – and it was caught during the walk-around inspection.
After the walk-around inspection is complete, the next step is to road test the vehicle and be sure to specifically check shock absorbers, springs, brakes, u-joints and wheel bearings to find problems that are developing or are already a problem. From experience, 4x4 vehicles that don’t run on paved roads will tend to develop problems in those areas.
Brake problems are often really easy to hear or feel on the drive, usually as a grinding noise or a pulsation when the brakes are applied. One important note on testing the brakes though, use caution if you decide to apply the emergency brake. If a mud-covered brake cable isn’t moving freely, you may be in for an unpleasant challenge getting it to release again.
Actually, it’s especially important to check for brake pulsation on jacked-up 4x4 vehicles in particular because their wheels tend to be switched out, removed or upgraded a bit more frequently than most vehicles – and not always torqued properly when they’re reinstalled. And since incorrect torqueing methods often warp the hub and brake rotors, this ends up causing a problem that shows up as a vibration when braking at highway speeds. Warped rotors reduce braking efficiency and can even cause a loss of braking if it’s severe enough, which is definitely not a good thing on a heavy, jacked-up vehicle. In fact, if you’re removing wheels on these units yourself, marking the bolt hole and wheel stud with tire chalk before removing it so that it can be reinstalled (and correctly torqued) in the exact position that it came off is very good practice and can prevent problems later on.
Additionally, during the road test check for nose dives or severe dips on braking – and of course, crunching noises over bumps. If these are present, check the shocks, springs (including leaf spring) and bushings carefully when you return to the shop. From experience, these components tend to break near the mounting points, especially on vehicles that have been outfitted with campers or quad decks. Having an assistant bounce it while you inspect the components may help. Cracks and breaks in these components are usually really obvious and easy to spot, but sometimes it’s easier to find problems if the vehicle is actually making the noise while it’s being checked.
Also, from experience, wheel bearings on newer 4x4 trucks seem prone to fail if the vehicle takes a pounding off road – no comment or judgement, it’s just something that seems to happen. Sadly the bearing failure is often catastrophic, in other words it actually separates from the vehicle with the wheel still attached, which is not good at all and a real challenge to drag out of the bush and back to the shop. Because of this, it’s especially important to check for signs of failed or failing wheel bearings when you’re on the road test.
Failed or failing wheel bearings tend to make a low, growling or humming noise at low to mid speeds and the noise changes as the vehicle swerves from side to side down the road (in other words, as the bearing is being loaded and unloaded – but don’t try this on a busy road!) There may also be play in the bearing or even visible damage. Getting into the habit of wiggling a wheel from side to side and up and down before removing it to check for play is good practice, since this can help identify many front-end problems, not just wheel bearing concerns. Either way, it’s really important to identify wheel bearing problems so the vehicle doesn’t end up getting dragged out in pieces.
Also be sure to check the air conditioning and heater to make sure they work and that the fan works on all speeds. Make sure the AC compressor engages, the belt and tensioner are OK, and inspect any cabin air filters. It’s simple enough to check, and it’s great to find the problem before the customer needs to use the system and is disappointed to find out that it’s inoperative.
And of course, as part of the road test, make sure the unit is actually going into 4-wheel drive smoothly. Since different manufacturers have slightly different procedures for putting the vehicles into 4-wheel drive, it may be worth referring to the owners’ manual (usually found in the glove box or online) – or since many manufacturers put this information on the sun visor, just flip it down and check to see if it’s written there.
Since many trucks don’t use manually locking front hubs anymore, confirming that the different actuators are functioning properly is key to making sure the vehicle is indeed going into 4-wheel drive and back out smoothly. Some vehicles even have rear differential actuators that lock the rear wheels for direct drive, in case the vehicle gets seriously stuck. No matter which system is used, it’s really important to check that it’s working properly.
Back in the shop
When the road test is over and the vehicle is back in the shop, cleaning the mud and debris off of critical components isn’t glamorous, but it’s an essential part of the inspection and important for keeping 4x4 vehicles running well (and it’s nice to avoid getting dirt down your neck while working). In particular, carefully cleaning out the radiator, condenser and any other coolers is critical so the vehicle doesn’t overheat, and also to prevent the components from rotting out too quickly. Never use a pressure washer in this area since that can remove any protective paint and permanently damage delicate coils and fins. Unfortunately, it sometimes takes a while to dissolve all the caked-on muck that collects in there but it still needs to be done – if you can get low-pressure hot water into the area, that may help speed things up. Actually, this may be something to do outside so that your work area stays somewhat clean and you don’t track dirt into any other customer vehicles. And when this is done, carefully inspect the cooling fins and coils for damage and leaks. Even jacked-up 4x4s need their coolers to be in good condition on their adventures.
Be sure to carefully check that the parking brake cables are clean and move freely – but remember that grease attracts dirt, so lubing them isn’t always a great idea (check the service information and follow what the manufacturer recommends).
Often the cables will break off completely and hang down, which is easy enough to spot if the customer hasn’t already noticed this. Many techs now refer to these as “parking brake” cables, not “emergency brake” cables for good reason – often the parking brake mechanism is attached to tiny shoes inside the rotors, which will be destroyed if they’re applied or used at any speed other than completely stopped. The parking brake components are definitely worth checking on a vehicle that regularly travels through water (even backing down a boat launch), since customers often forget to release the brake when they drive away, and on jacked-up 4x4 vehicles they probably won’t even notice when the parking brake subsequently blows apart. Depending on the vehicle, the customer may not even notice the ensuing rattling noise from the rear wheels either.
Also carefully look at anything on the vehicle that hangs down or is exposed, since it may well have been damaged by rocks, mud or various projectiles. It’s also a good idea to carefully check the oil filter, oil pan and transmission which, depending on the design, may well be getting hit when the vehicle goes over uneven ground.
Sadly, many engines have been damaged beyond repair because the oil filter got knocked off or crushed, or a rock went through the oil pan – one customer actually had us put a murphy switch on his truck to stop the engine immediately if oil pressure was suddenly lost (he didn’t trust the warning light on the dash). Even fuel filters that hang down can also be damaged during off-road use. Also, power steering lines are known to break off, so it’s worth checking them out, too.
While you’re inspecting the underside of the vehicle, also make sure that the spare tire is in place. If the spare tire is mounted under the vehicle, check the hoist and cable holding it in place carefully. Spare tire “hoists” are known to fail, resulting in the spare tire falling off the vehicle completely (customers usually have no idea that happened), so it’s important to check that the tire is indeed in place and also that its pressure is correctly set.
Another note on tires – driving over gravel or through streams is tough on tires so carefully inspecting the sidewalls for deep cuts and blisters is worthwhile. Additionally, mud often (okay, always) gets packed into the inner rims, which can cause vibrations when the vehicle gets back onto paved roads. This problem is easy enough to fix, especially if the wheels are removed for service – rinse or gently scrape it out, being careful not to damage the wheel or remove any stick-on wheel weights so you don’t cause any new vibrations in the vehicle.
Actually, tire wear on jacked-up 4x4s may be caused by surprising events. One of our customers lent his “monster truck” to the woman he was dating, and she videotaped herself doing burn outs through town. They’ve broken up, so I’m not sure who paid to replace the ensuing worn-out tires.
And finally, if the unit has been indeed stuck and recovered recently, make sure to not only check that the retrieval or tow hooks are still intact, but also inspect anything that may have been mistakenly used as a retrieval point. For some reason tie rod ends and steering linkages are often mistakenly used to retrieve stuck vehicles and end up being horribly bent or crushed. And since steering components can’t be straightened out and reused, any damaged components will need to be replaced if this was indeed the case.
If you do find yourself replacing steering components, one tip from a heavy-duty tech who tries to make alignments as quick as possible (while still doing an excellent job) is to not only count the number of turns or threads when removing a component (so that the alignment is close to what it was before), but to actually get a tape measure and measure the distances before the component is undone and make sure the distances are the same when the new component is installed, in order to make the alignment go as smoothly as possible. Since it’s often tough to get a jacked-up truck onto an alignment rack and then perform the alignment on components that are seized in place, this is good advice indeed.
Also inspect the components that might have been in the path when the retrieval chain or sling was pulled tight, such as tie rods, steering linkages, fuel and brake lines, oil cooler pipes, transmission and engine lines. Depending on who pulled the unit out – and how – they may have inadvertently damaged something critical that now needs to be replaced or repaired.
You probably already know that 4x4 vehicles need their components flushed and filled regularly, but there’s so much more to servicing jacked-up vehicles than just that. Vehicles that go off road regularly need to be carefully inspected to prevent and repair the problems that other vehicles (the ones used mostly on paved roads) simply don’t experience.
Again, this really isn’t difficult.
With practice and experience, you’ll be able to make sure jacked-up 4x4s make it into your service bays – happily — and then back out to the hills, to play in the mud and sand again.
