Wheel-End Problems? Signs and Symptoms

It’s important to keep a close eye on things when it comes to detecting wheel-end problems with your Mitsubishi Fuso, Isuzu, Hino, or UD freight truck. Careful observation can reveal early signs and symptoms of wheel-end problems before bearings are damaged and need to be replaced. With immediate inspection and maintenance, you can reduce bearing damage in conventional wheel ends, and save on long term costs. Begin with a simple walk-around wheel inspection.

Walk-Around Wheel Inspection

Bearing damage may have already begun if you notice:

  • Low lube level in a hub cap sight glass
  • Hub cap sight glass that is discolored or burnt
  • Smoking or extremely hot hub cap (too hot to touch)
  • Abnormal tire wear
  • Lube leakage on any external surface of a wheel hub or tire, both inboard and outboard sides (this sometimes appears as a lube swirl or spiral pattern on a hub or tire surface)

Driver Observation

Bearing damage may have already begun if the driver notices:

  • Wheel vibration
  • Wheel Wobble
  • Wheel noise
  • Smoke from wheel end
  • Increased stopping distance or decreased braking power
  • Increased fuel consumption
  • Abnormal side pull when brakes are applied
  • Wheel lockup or skidding
  • Risks of higher maintenance costs and wheel end separation increase if these warning signs are ignored and if wheel-end inspection and maintenance is not performed
  • Evidence of more advanced wheel end problems can be seen when wheel-ends are disassembled for regular maintenance

Wheel-End Disassembly Analysis

Bearings may need to be replaced if you observe:

  • Any nut face wear (adjusting nut or lug nuts)
  • Bearing noisy when rotated
  • Rust or moisture on any surface
  • Spindle wear (bottom half shows more than top half)
  • Thread wear
  • Hub bore wear
  • Loss of adjusting nut torqque
  • Bearing has been dropped
  • Worn out or damaged seals

Bearing must be replaced if you observe:

  • Visual wear on any other bearing surface
  • Any dents on the cage of the bearing assembly
  • Dry, caked lube in the hub caps or any other internal cavity
  • Metal particles in the lube, hub caps, hubs or bearings
  • Heat discoloration on the bearings or any other internal component (don’t confuse heat discoloration, which is non-removable stain and metal flow, with lube staining that is easily removed with fine emery cloth.)
  • Evidence of the cups or cones spinning or turning (grooves on the cone backface, bore or spindle)
  • Spalling (flaking away) of bearing material on races or roller bodies
  • Any raised metal or dents on the rollers or races
  • Drivers and service mechanics/technicians that develop a keen eye for observing these signs and symptoms of wheel end problems can help lower maintenance and repair costs and may help prevent wheel-end separations

Signs and Symptoms of

How To Tell If Your Engine Block Is Cracked

The coolant in your Mitsubishi Fuso, Isuzu, Hino, or UD freight truck operates in a closed system, meaning that it circulates from the engine’s cooling passages to the radiator, the heater core and back again. It should never leave that loop. If somehow getting into the oil passages or the cylinders (and, from there, out the tailpipe) something has gone terribly wrong. Your head gasket has cracked, your head itself has cracked or, worst of all, your block has cracked.

You can crack an engine block many different ways, but some of the more common ways are:

– Running water through the cooling system instead of antifreeze in cold weather
– Running cold water through an already hot engine

A cracked engine block can cause performance troubles with any Mitsubishi Fuso FE, FH, FK or UD 1200, 1300, 1400, 1800 or 2000 series, Isuzu NPR, NQR, GMC W3500, 4500, 5500, any other mid size truck or even regular passenger cars, and in time, can cause your vehicle to stop running altogether. Fortunately, there are ways to identify a crack in the engine block, which can help lead to repairs or replacements.

  1. Look for leaking engine coolant, most notably as it drains out the bottom of a car. This is a telltale sign of a cracked engine block, and in time, can cause an engine to overheat.
  2. Check the dashboard and check gauges. If any of the dashboard lights come on, whether related to oil or coolant, this could signify a cracked engine block. Also, if the temperature gauge begins to signal overheating, this could mean engine coolant is leaking, which is a potential sign of a cracked engine block.
  3. Look for extra smoke coming out of an automobile’s exhaust pipe. While a certain amount is common, extra amounts–long trails coming out of an exhaust pipe–could signify a cracked engine block.
  4. Check to see if a car radiator’s mixture of engine coolant and water is optimal. This should be half water, half antifreeze, in most cases (it will often be indicated on an antifreeze bottle’s instructions). If the mixture is not proper, this can cause the mixture to freeze, which will crack the engine block.

There are very few engine failures that any mechanic would consider beyond repair, but first among them is the cracked engine block. The end result is generally irreparable damage. Additives like sodium silicate (a.k.a. “liquid glass”) can help delay complete failure of a slightly fractured block, but it will never be as strong or reliable as it once was.

Engine Block Cracked?

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Low Antifreeze But Nothing On The Ground – Where Is It Going?

There is no sign of antifreeze dripping on the ground beneath your vehicle, but you frequently add coolant and continuously find your Mitsubishi Fuso, Isuzu, Hino, or UD freight truck low on antifreeze. Where is it going?

Coolant can leak from the water jacket into several parts of the engine. The most common leaks are –

Oil galley / return (ends up in the oil pan) – A visual inspection of the oil, oil dipstick, oil filler cap and PCV valve may show a white, milky film of homogenized oil and coolant. An increase in oil level or the bittersweet smell of ethylene glycol on the dipstick are solid evidence of a significant internal leak.

Combustion chamber – The smell of coolant or a whitish cloud of smoke from the exhaust at start-up can be an indicator of coolant in the combustion chambers. If this is the case, it can be confirmed by a chemical test for exhaust hydrocarbons in the coolant.

Heater Core – The heater core is located inside the heating ventilation and air conditioning (HVAC) unit under the dash. It is out of sight so you cannot see a leak directly. Look for stains or wet spots on the bottom of the plastic HVAC case, or on the passenger side floor.

Water pump – If you have a bad shaft seal, coolant can dribble out of the vent hole just under the water pump pulley shaft. If the water pump is a two-piece unit with a backing plate, the gasket between the housing and back cover may be leaking. The gasket or o-ring that seals the pump to the engine front cover on cover-mounted water pumps can also leak coolant. Look for stains, discoloration or liquid coolant on the outside of the water pump or engine.

Intake Manifold gasket – The gasket that seals the intake manifold to the cylinder heads may leak and allow coolant to enter the intake port, crankcase or dribble down the outside of the engine.

Radiator – Radiators can develop leaks around upper or loser hose connections as a result of vibration. The seams where the core is mated to the end tanks is another place where leaks frequently develop, especially on aluminum radiators with plastic end tanks. On copper/brass radiators, leaks typically occur where the cooling tubes in the core are connected or soldered to the core headers. Internal corrosion caused by old coolant that has never been changed can also eat through the metal in the radiator, causing it to leak.

Hoses – Cracks, pinholes or splits in a radiator hose or heater hose will leak coolant. A hose leak will usually send a stream of hot coolant spraying out of the hose. A corroded hose connection or a loose or damaged hose clamp may also allow coolant to leak from the end of a hose. Sometimes a leak may only occur once the hose gets hot and the pinhole or crack opens up.

Freeze plugs – These are the casting plugs or expansion plugs in the sides of the engine block and/or cylinder head. The flat steel plugs corroded from the inside out, and may develop leaks that are hard to see because of the plug’s location behind the exhaust manifold, engine mount or other engine accessories. On V6 and V8 blocks, the plugs are most easily inspected from underneath the vehicle.

Relatively simple, inexpensive tests can identify specific internal coolant leaks.