So Fix it

The 200R4 is the model number of a transmission introduced by General Motors (GM) in 1982. This transmission is compatible with the GM Chevrolet, Buick, Pontiac and Cadillac brands. Owners can obtain key information about the transmissions workings in their cars by reviewing their history, critical systems, gear ratio, dimensions and horsepower.

History

GM introduced the GM 2004R as an overdrive version of the three-speed GM THM300 model. It offered a vast improvement in strength and durability over the THM200. Because the 200R4 was similar in size to the GM TM400 model, the 200R4 eventually replaced the THM 400 model.

Critical Systems

The internal hydraulic pump is the most critical part of the 200R4 transmission. The pump housing is precision-machined. Because of this precision, its performance level is impervious to heat, pressure and the age of the transmission.

Gear Ratios

The first gear ratio is 2.74-to-1, the second gear radio is 1.57-to-1, the third gear ratio is 1.0-to-1, the fourth gear ratio 0.67-to-1 and reverse is 2.07-to-1.

Dimensions

From the dimensions and the fit, an owner can determine the size, make and model of vehicle with which the transmission is compatible. The overall length of the transmission is 27- 11/16 and height is 19 1/8 inches.

Horsepower

The 200 R4 can reach up to 500 horsepower and requires a 12-volt feed to control the torque converter.

The emission controls on an Oldsmobile Cutlass are fully integrated with ignition and fuel system controls. All of these control systems work together to ensure the engine works efficiently with minimal production of harmful exhaust gases.

Crankcase Ventilation System

The crankcase ventilation system controls unburned fuel vapor that leaks from the pistons into the crankcase. Normally these vapors would leak into the atmosphere since they are under pressure. If left alone they contaminate the engine oil and allow sludge to build up in the crankcase. The crankcase ventilation system recycles these gases back into the air intake so they can be re-burned in the pistons. The Positive Crankcase Valve (PCV) controls how much of the gas is recycled at any given time.

Evaporative Emission Control System

The Evaporative Emission Control System (EEC) is a carbon canister that reduces emissions of fuel vapors from the fuel system. It stores fuel vapors and vents them through a filter containing activated charcoal. The charcoal absorbs vapors while the engine is not running. The charcoal releases the vapors into the air intake manifold when the engine is running. A solenoid closes the canister to air when the engine is turned off so that fuel vapor is not lost to the atmosphere.

Exhaust Gas Recirculation System

The Exhaust Gas Recirculation System, or EGR, reduces oxides of nitrogen emissions. Nitrogen oxides are often written as "NOx" and they are harmful to human and animal health. The EGR is a valve which, under certain conditions, allows some exhaust gas to recirculate into the intake manifold. The exhaust gas then cools combustion temperature and controls detonation of the fuel/air mixture. The EGR valve is mounted on the intake manifold and uses manifold vacuum to open up and vent some exhaust gas into the intake manifold. It is activated only when the engine reaches normal operating temperature. Too much exhaust flow into the intake manifold can cause stalling after a cold start or during deceleration.

Thermostatic Air Cleaner

The Thermostatic Air Cleaner (THERMAC) warms air entering the carburetor when the engine is cool and maintains a controlled air temperature into the carburetor. This reduces the amount of time the choke needs to be on and results in better fuel economy and lower harmful emissions.

Air Management System

The Air Management System injects oxygen into the exhaust ports, exhaust manifolds and catalytic converter to burn off any fuel vapor left in the exhaust gas. The system shuts off only during deceleration or rapid acceleration to prevent backfiring. The system reduces the levels of hydrocarbon and carbon-oxygen combinations in exhaust gases.

Todays vehicles usually have wheel bearings as part of a whole hub assembly. Wheel bearings are the only part that connects the vehicles body to its wheels. Knowing when they need to be replaced and the tools required can be useful information for vehicle owners.

Identification

There are several ways to identify a faulty wheel hub bearing assembly, most notably if the vehicles ABS warning light comes on. Strange noises, while turning the steering wheel, are another sign of a bad hub bearing assembly. These include growling or humming noises, usually at speeds around 35 MPH.

ABS Sensors

Many of todays vehicles are equipped with anti-lock brakes. Often times these vehicles will have anti-lock brake sensors built directly into the hub bearing assembly. On vehicles where this is the case, if the sensor goes bad, then replacing the entire hub assembly will be necessary to remedy the problem.

Tools

You can save money by replacing a hub bearing assembly yourself if you possess the know-how and the right tools. Some of the tools needed include a floor jack, a flat head screwdriver, sandpaper and a rubber mallet.