What Does the Letter in General Motors’ Body Styles Mean?

GM X Body Style
General Motors X Body Style

General Motors uses letter codes to signify which chassis layout, or body type, the vehicle has. This is useful since GM consists of many different makes such as Chevrolet, Oldsmobile, Pontiac, Buick, and Cadillac. Many of these brands share platform types with each other. It isn’t some secret, alphabetic code that GM fans are privileged to. It is really quite simple. Each platform has changed somewhat over the years so we’ll walk through them in more or less chronological order.

 

The Early Years

GM started with just four platforms: the A, B, C, and D bodies. In the beginning, A and B were both for full size cars. A body models included the Chevy Superior, the Oldsmobile 60, and most Pontiacs. The B Body was used for the Buick Century among others. GM decided it didn’t make sense to have two platforms for full size cars so the A body was discontinued and the B Body became the standard for full sized cars in 1959. GM continued to use the B body designation for full size, rear-wheel drive cars until 1996. The Chevy Bel Air, Buick LeSabre, Chevy Impala, and Pontiac Bonneville were all built on the B body platform in this era.

In 1931, GM Introduced the C body. The C body would continue as a long wheelbase RWD car until 1984. The C body was essentially a lengthened version of the B body. The Pontiac Torpedo, Buick LaSalle, and Oldsmobile 90 were built on this platform.

The D body was used from 1936 to 1996 for GM’s biggest cars, like the Cadillac Fleetwood Limo and the Buick Limited.

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How to Tear Down a VR6 Long Block Engine

This is a 12 valve 2.8L VR6 engine out of a 2001 Volkswagen Jetta. This engine can be particularly complicated to tear down due to the rear engine timing and the need of a few special tools. Having a rear timing camshaft makes for some difficulties when removing the lower timing cover. For this, there are stand adapters for the mounting points to be moved to the side of the engine instead of using transmission mounting points. In this article, we will be using a regular transmission mounting point.

Tools Required:

  • Basic Metric Socket Set
  • Large breaker bar
  • Impact gun for balancer bolt (optional)
  • 5mm Allen key
  • 6mm Allen key
  • 12mm deep triple square socket
  • 10mm triple square socket
  • 27mm Socket (For the timing chain tensioner & harmonic balancer bolt)
  • Dead blow hammer or rubber mallet
  • Permanent marker
  • Plastic zip lock bags of various sizes
  • Flat head screw driver

Step 1: Index, Tag, and Organize the Engine Parts

To start, you want to simply remove all accessories, pulleys, and other pieces to get the engine down to just the long block. Then drain all the fluids.

NOTE: The intake manifold uses a 5mm hex bolt (i.e. Allen head bolt). You will need a 5mm hex socket driver with extension or a long T-handle style hex driver to remove these.

Once your block is reduced to a long block, you are now ready to tear down your engine. Before writing this article I had already reduced this engine to a long block, so all photos were taken after that point.

Before you start unbolting things, most overhead camshaft engines will have a particular order for removing parts. It is not as simple as going from top to bottom. The first step is to get your permanent marker and plastic bags. The most important rule for an engine tear down is to index, bag, and tag everything you remove. This is particularly useful if you plan to re-assemble it in the future. This is also a good time to loosen your crank bolt with an impact gun. Having the resistance of the rotating assembly and valve train will aid in getting that bolt loose.

Step 2: Remove the Valve Cover

The front of the engine will have two long studs, and you will need a deep socket or an open-end wrench to loosen them. These VR6s have the plastic version of the valve cover and can be brittle depending on the engine’s age. Use a soft mallet to tap on corners of the cover in conjunction with plastic pry tools if needed.

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Why do Gas Prices Go Down in the Winter?

IMG_20130428_065835

Gas prices always seem to be lower in the winter than in the summer.  All the things that make gas prices rise and fall can be pretty convoluted, and a lot of factors play into seasonal price differences.  There’s higher demand in the summer, with people going on vacations, and generally getting out more and doing more driving.  The biggest factor that makes gas cost more in the summer is that the gasoline is actually different.Continue Reading

The True Story of Chitty Chitty Bang Bang

Remember Chitty Chitty Bang Bang, the kids’ musical about the flying car?  Did you know it was based on a real car?  The real one couldn’t fly (at least not in the literal sense), but it did have one thing in common with an airplane: the engine.

In the early days of motoring, there really was no replacement for displacement.  Engineers hadn’t yet figured out how to make reliable engines that ran over 3000 RPM.  The only way to squeeze more horsepower out of an engine was to increase the volume.

Many very large engined cars were designed for racing and to test land speed records in the early 20th century.  Arguably the original was the famed Blitzen Benz, whose 21.5 liter engine could output 200 horsepower at 1,500 RPM.  Not wanting to be outdone, Fiat constructed the Tipo S67, using a 28.5 liter, four cylinder airship engine.  The S67 could output 300 hp at 1,900 RPM.  Continue Reading

Nine Cars That Never Existed, Even if You Thought They Did

Have you ever seen a 1996 Jeep Wrangler?  How about a 2001 Cadillac Escalade?  If you’re about to say yes, hold on and think again.  A number of models through automotive history have skipped model years.

Even though your car may have been manufactured or sold in that year doesn’t mean that’s what year it is.  If that sounds confusing, it’s because model years are confusing.  Though a car might be, for example, a 2015, doesn’t mean it was actually built in 2015.  Car companies want to have the car already at dealerships by the start of the year.  So, in most cases, the new model year is released in the last quarter of the previous calendar year.  A 2015 might be introduced in October 2014, say.

That’s not a hard and fast rule, though.  Automakers can release a new model year as early as January 2 of the previous calendar year.  That is to say, a 2015 car can be sold as early as January 2, 2014.  Sometimes car companies will make a new generation of a car an early release.  In other cases they might extend the sales of one model year into the next calendar year if the new generation is not yet ready.  That is how most skipped model years happened.  Here’s a quick chronological list Continue Reading

Should I Get Snow Tires?

tire

Winter tires, or snow tires, as some people call them, can be a big benefit in winter driving.  They give your wheels a better grip on the road, which means you’ll have better traction, handling and braking.

There are two main differences between winter tires and your standard, all-weather tires.  First, winter tires are made of a more pliable form of rubber than all-seasons.  Rubber tends to get stiff when it’s cold.  A stiff tire won’t flex to conform to the road.  That means your tire has less contact with the road when it’s cold.  Pliable snow tires do better meeting their surface against the road.

The other major difference is that snow tires have something called sipes.  If you look at a snow tire up close, you’ll notice that in addition to the treads there are tiny little inlets (much thinner than the tread grooves).  These are the sipes.  The sipes Continue Reading

5 Scary Signs of Failing Shocks

struts

You’re driving down a back country road at night. Over the howls of the wind, you can hear a rattle and clunking. Is your car haunted or do you just need to fix your suspension? Here are 5 signs that your shocks or struts might be ready to pass on to the great beyond:

1. A Sinking Feeling

Worn springs can lead to decreased ride height. Check your ride height and then compare it to specifications for your model. If you’re riding too low, it’s time to replace your shocks and springs. You might also notice that your car bottoms out on rough roads, speed bumps, or when you’re coming into or out of your driveway.

2. It’s Alive!

You might notice that your ride is livelier that you’d like it to be. Continue Reading