AUTOMOTIVE TECH TIPS
Axles, Steering & Suspensions
The degradation of the Rubber Bushings in the front suspension control arms, is one of the major causes of front-end shimmy in many cars.
Always replace the Tie Rod Assemblies and the Center Track Rod at the same time. Replacing one worn unit will accelerate the wear rate of the units not replaced by an order of magnitude as a result of displaced stress loads.
Worn Idler Arm Bushings cause front-end steering shimmy and can negate the responsive feel the steering demonstrates, when competent.
Wheel Bearings cannot be replaced separately on complete hub assemblies. Both left and right sides should be changed at the same time.
Check rear Halfshaft Boots for tears. A torn Boot could allow road dirt and moisture to destroy CV joint within a short time.
It is recommended that Shock Absorbers be matched between the front and rear suspension systems. The interchange of mismatched units between front and rear systems can demonstrate adverse handling effects.
It is important to inspect the Shock Absorber Mounts and Spring Pads in both the front and rear of the car. Designate replacement when shock absorbers are replaced to avoid the duplication of labor.
Cooling System
Generally speaking, a lower temperature Thermostat will not improve cooling system efficiently if other components, such as the radiator and the water pump are not providing adequate assets to remove the heat generated. Inspect the entire cooling system prior to replacing the thermostat as a “quick fix”. On cars equipped with Timing Belts, it is a prudent recommendation to replace the Water Pump while incurring the labor of belt replacement.
Check to see that the radiator fan or auxiliary fan is free of leaves and road debris to ensure efficient function. Overheating? If you find brown foamy residue in your coolant you may have a cracked cylinder head, causing overheating.
Overheating? Have your radiator pressure checked at your local radiator shop. Pressure loss can cause overheating. Many times a failed radiator cap is the culprit Cooling System.
Broken radiator fan blades can quickly destroy the water pump shaft bearing.
Radiator Caps should be inspected, tested and replaced as necessary. A cap that has failed to hold system pressure can cause coolant loss and overheating conditions.
In many cases, boiling of a radiator will not improve its cooling efficiency significantly, and it is best to replace the radiator or have it re-cored.
Thick brown sludge in the overflow tank indicates a cracked Head or bad Head Gasket.
Cooling System Hoses have a tendency to fail by either becoming soft and gummy, or by drying and cracking. It is recommended to change all Cooling System and Heater hoses between 80-100,000 miles or every 4 years, whichever comes first.
Drivetrain
Pressure Plate, Disk and Throw-Out Bearing should be changed at the same time to avoid duplication of labor, along with the Main Shaft Pilot Bearing that is located in the end of the crankshaft.
The Main Shaft Pilot Bearing should be changed with each clutch system replacement and may require a special extrcator tool to accomplish this removal.
Flywheel Bolts should be changed whenever Flywheel is reinstalled. Thread pitch changes as a locking device, and they cannot be reused.
Transmission Seals are easily accessible when the transmission is removed from the car during a clutch or engine replacement, this is the time to consider the replacement of these inexpensive parts, if needed.
The number one cause of shifting complaints is caused from the parts that are external from the transmission housing itself and are easily replaced without the removal of the transmission Drivetrain
Flywheel should be replaced if it is heavily grooved or blued from heat distortion. It is not recommended that flywheels be machined as the necessary cut to even the surfaces, will remove the heat treating in the face of the flywheel, thereby shortening its life substantially.
Limited slip differentials enhance not only dry spirited driving, but also increase foul weather driving stability.
Measured bolt length is the distance from the end of its threads to the bottom of the head.
Driveshaft Center Support Bearing assemblies are suspended in a rubber median between the bearing and the outside shell. This rubber median has a tendency to deteriorate prior to the bearing itself; softening and causing drive shaft vibration and oscillation as a result.
Failure to change the Flex Disc Lock Nuts may cause catastrophic damage to the transmission, the drive shaft and associated linkage components.
Center Support Bearings and Flex Discs should be inspected on a regular basis. If you feel a vibration, upon acceleration, on the driveshaft tunnel, failure is imminent.
Oils and Oil Changes
Synthetic engine oil reduces engine wear. It can withstand much higher temperatures, therefore it will not shear down (lose viscosity), at high engine speeds. It can withstand sub-zero temperatures and not gel.
Oil changes should be preformed every 5000km or 6 months withever comes first, some new vehicles should be at the manufacturers specs.
Mounts
Excessive engine movement indicates worn or broken mounts.
Broken or weakened Engine Mounts can cause sufficient engine movement to incur exhaust system failures and interference between the Cooling Fan and Radiator, thereby causing catastrophic failure.
Transmission and Engine Mounts have a tendency to become gummy from prolonged oil saturation. It is a prudent recommendation to replace mounts which have been subject to these conditions.
Engine oil should be changed every 2500-3000 miles along with the oil filter for non-synthetic oils. Synthetic oils can increase this interval to between 5000 and 10000 miles. This is the cheapest preventive maintenance insurance you can buy. High performance cams should only be installed in a freshly rebuilt engine. In order to get the optimal performance from a High Performance Camshaft, a free flow exhaust system and intake system are required for adequate breathing. More to come…