Wednesday 8 January 2014

4WD CARE/PRE TRIP INSPECTIONS

What are you getting for your money with a pre trip inspection? What are good mechanics on the look out for to ensure your 4WD makes it through that big trip?

A pre trip inspection should take around an hour and we always start with the radiators and cooling system. Modern 4WD’s can have transmission coolers, a/c condensers and intercoolers that can have bugs and all sorts of muck that can impede flow to the radiator. We had a couple of cruisers that got blocked that bad we had to remove the coolers individually and unblock them with a gurney and compressed air. Also check the coolant is in good condition and not water diluted and contaminated with rust or oil.

BATTERIES AND ALTERNATORS

Every pre trip inspection should include an electrical assessment of the charging system. You don’t need to be an auto electrician to clean battery terminals and top it up with water but any parasitic drains or bad charge rates need to be sorted. Any new equipment (i.e. Fridge, Spotlights etc) needs to be locally tested before getting into a remote area and realising the alternator isn’t up to the job. Water, salt, dirt and electrical currents all give your connections a very hard time and regular maintenance is required. If wiring up your own accessories make strong water proof connections. There are a variety of contact cleaners available. I prefer WD40 or CRC5.56 together with a light scrubbing of the dirty connections with sandpaper.



WHEEL BEARING AND CV CARE


Wheel bearing maintenance is critical for your own safety and good reliability. Most manufacturers recommend 100000km service interval for replacement but heavy off road driving demands this interval be shortened. It is important to inspect brakes as well as suspension components when you have the bearing assembly apart. There are a number of different greases available and you have got to be certain that you use a high speed bearing grease. If you are unsure just get down to your local bearing and industrial supplier and they will give you the right one. They also make good bearing packs and can sell any belts and seals you might need. The vehicle should be jacked up and checked for smoothness and good adjustment. Also give your ball joints a good shake and change them as required.



Left to right CV Joint Grease, Purple high tack bearing grease (what we use), Valvoline and Mobile blue grease(high speed bearing) Extreme high pressure grease for earth moving.

GEARBOX AND DRIVE LINE CARE

Many 4WD’s go through two or three gearboxes compared to maybe one motor. Lack of care/leaks and bad oil are the number one killer of boxes. In their operation they generate metal and that needs to be drained and refilled with good quality oil at regular intervals. Upgrades like oil saver hoses on the cruisers can save money long term if you have a failure with your gearbox output shaft seal. Transfer case oils get a lot of steel and heat and need to be kept in good condition. If you drain out a lot of steel it is cheaper to get it repaired sooner rather than later when more serious damage occurs. Most reconditioners charge extra if the core return has a hole in the side it.



Gearbox and transmission oils in 20l packs. These containers could do 2 major drive line services on this cruiser.

ENGINE CARE

Diesel engines need good servicing or their life will be reduced. Regular oil and filter changes are really important and also don’t forget about timing belt intervals. Any smoke needs to be looked at and there are three different types that diesel mechanics look out for.

White Smoke – This generally indicates partially burnt fuel or coolant getting into the combustion chamber via the head gasket (also check air cleaner after a dusty trip). Also with 1HZ motors when you have white smoke on a cold start up and it clears up you know straight away that you have glow plug issues. 1HZ motors are indirect injected and rely heavily on glow plugs for starting. If the motor won’t fire up straight away don’t burn out your starter because they can crank over all day and not start with out plugs. If you get caught out in the bush with a glow plug wire fault under the dash somewhere you can use a jumper wire from the battery straight on to the glow plug and be able to get home. Bad fuel can also give you a white smoke if it doesn’t stop a diesel motor. It is important to drain your fuel water separator regularly and use some diesel conditioner if fuelling up out of drums in remote areas.

Blue Smoke – This generally indicates oil burning and means rings or a turbo seal are faulty. When you get a seized piston you get a combination of white and blue as the seal on the bore is that bad there is a lot of oil as well as not enough compression to burn the fuel.

Black Smoke – This generally indicates over fuelling or a bit of injector dribble. In this condition the fuel is completely intact as opposed to white smoke which is partially burnt and is doing no useful work.





This 1HZ has an aftermarket turbo and 300 000 kms on the clock. It is well looked after and doesn’t smoke or leak.

Will my older 4WD make it on that big trip?

Older style diesels are tough they can take some bad fuel and you don’t need a scanner or expensive diagnostic equipment to tackle a fault. If they are well looked after they can be just as reliable as their newer counterparts. They have heavy duty rugged motors in them and parts are readily available and as well as cheap. If you have a mechanical problem just some common sense and basic knowledge will get you on your way. I recommend an older style 4WD for DIY mechanics and people on a tight budget. Pajeros and Jackaroos are good capable off roaders and can found cheap on the second hand market. Landcruisers and hiluxes hold their value and are great 4WD’s.They are a bit more crude but if you do break something on them you don’t have to take out a second mortgage to fix it.

Enjoy your 4WD and keep safe 

Sam 
Head Mechanic 
Express Diesel Service 
www.expressdieselservice.com.au


Express Diesel Service offers extensive pre-trip servicing. Check the website for our contact details.

 

 

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