Troubleshooting Car Vibration – The Three Types Of Driveline Vibration

There are several different possible causes for a driveline vibration. Your wheels, tires, axles, driveshaft, transmission, clutch or torque converter and engine components are all rotating at a high rate of speed, and any one or more of these components can create a vibration if they are worn or out of spec. Worn or broken engine or transmission mounts can transmit normal vibrations that usually aren’t ever felt, and accidental body contact with the engine, transmission, or exhaust can also be misinterpreted as a driveline vibration. The first step in diagnosing a classic car vibration is to determine exactly when and under what conditions the vibration occurs.

There are three basic types of vibrations:

1. Engine RPM related – If the vibration is related to engine RPM, it will occur in all gears (and possibly even sitting still) at a particular engine RPM or above. This vibration usually can be attributed to the engine itself or anything else that turns at the same speed as the engine, such as the harmonic balancer, flywheel or flexplate, pilot bearing, pressure plate, torque converter, or transmission input shaft. It is also possible for body contact with the engine, transmission, or exhaust to cause an engine RPM related vibration. Worn or broken engine or transmission mounts can contribute to this problem. When driving the vehicle with the vibration present, maintain vehicle speed and try shifting to a lower or higher gear. If the vibration changes or goes away while maintaining the same vehicle speed, then the problem is not related to engine RPM.

2. Vehicle Speed related – If the vibration is related to vehicle speed, it will not be present until you reach a certain speed, and then it will usually start gradually and then become worse as speed increases. In some cases, it will decrease at some point, and then come back again at a higher speed. This type of vibration could be related to your wheels, tires, axles, differential, driveshaft runout, balance, or angles, universal joints, or transmission output shaft. Try the same driving test as above. If the vibration is present in third gear at 50 mph, but shifting to fourth gear at 50 MPH makes the vibration go away, then it is not going to be vehicle speed related and you can usually rule out any rotating component that is further back than the transmission output shaft. At a given MPH, your output shaft, driveshaft, axles, wheels and tires are all turning at a constant speed, no matter what gear the transmission is in.

3. Accel/Decel/Cruise related – A vibration that changes depending on whether you are accelerating, decelerating, or cruising at a steady speed could have quite a few different causes. Generally, this will be related to driveshaft angles or a worn or broken part, instead of something being out of balance. Think about what changes when the engine is under load. The engine and isolator mount loads shift; the load on the pinion bearing changes; your driveshaft angles change, possibly more than they should due to a broken engine or transmission mount; your exhaust, shifter, transmission, etc. could be contacting the body only on accel or decel; if the car has been lowered (or raised), your suspension snubbers could be contacting the body prematurely.

A vehicle works as a system, and you have to understand the relationships between all the different parts when you are trying to diagnose a driveline vibration. Determining if the vibration is related to engine speed, vehicle speed, or engine load will help you narrow down the list of possible culprits, and keep you from wasting your time looking in the wrong places.

Automotive Vibration Troubleshooting – The Three Types of Driveline Vibration

There are several different possible causes for a driveline vibration. Your wheels, tires, axles, driveshaft, transmission, clutch or torque converter and engine components are all rotating at a high rate of speed, and any one or more of these components can create a vibration if they are worn or out of spec. Worn or broken engine or transmission mounts can transmit normal vibrations that usually aren’t ever felt, and accidental body contact with the engine, transmission, or exhaust can also be misinterpreted as a driveline vibration. The first step in diagnosing a classic car vibration is to determine exactly when and under what conditions the vibration occurs.

There are three basic types of vibrations:

1. Engine RPM related – If the vibration is related to engine RPM, it will occur in all gears (and possibly even sitting still) at a particular engine RPM or above. This vibration usually can be attributed to the engine itself or anything else that turns at the same speed as the engine, such as the harmonic balancer, flywheel or flexplate, pilot bearing, pressure plate, torque converter, or transmission input shaft. It is also possible for body contact with the engine, transmission, or exhaust to cause an engine RPM related vibration. Worn or broken engine or transmission mounts can contribute to this problem. When driving the vehicle with the vibration present, maintain vehicle speed and try shifting to a lower or higher gear. If the vibration changes or goes away while maintaining the same vehicle speed, then the problem is not related to engine RPM.

2. Vehicle Speed related – If the vibration is related to vehicle speed, it will not be present until you reach a certain speed, and then it will usually start gradually and then become worse as speed increases. In some cases, it will decrease at some point, and then come back again at a higher speed. This type of vibration could be related to your wheels, tires, axles, differential, driveshaft runout, balance, or angles, universal joints, or transmission output shaft. Try the same driving test as above. If the vibration is present in third gear at 50 mph, but shifting to fourth gear at 50 MPH makes the vibration go away, then it is not going to be vehicle speed related and you can usually rule out any rotating component that is further back than the transmission output shaft. At a given MPH, your output shaft, driveshaft, axles, wheels and tires are all turning at a constant speed, no matter what gear the transmission is in.

3. Accel/Decel/Cruise related – A vibration that changes depending on whether you are accelerating, decelerating, or cruising at a steady speed could have quite a few different causes. Generally, this will be related to driveshaft angles or a worn or broken part, instead of something being out of balance. Think about what changes when the engine is under load. The engine and isolator mount loads shift; the load on the pinion bearing changes; your driveshaft angles change, possibly more than they should due to a broken engine or transmission mount; your exhaust, shifter, transmission, etc. could be contacting the body only on accel or decel; if the car has been lowered (or raised), your suspension snubbers could be contacting the body prematurely.

A vehicle works as a system, and you have to understand the relationships between all the different parts when you are trying to diagnose a driveline vibration. Determining if the vibration is related to engine speed, vehicle speed, or engine load will help you narrow down the list of possible culprits, and keep you from wasting your time looking in the wrong places.

Keith Farren is an ASE Certified Master Technician with a BS in Business Administration, an Associate degree in Automotive Technology, and over twenty years experience in the automotive industry. He also operates two websites dedicated to classic cars and automotive repairs, Classic Car Financing and Loans and Auto Window Repairs.

Electric Cars – How To Build Them

While many people I talk to tell me that there is no way the they could build electric cars themselves, I tell them they are dead wrong. After helping 4 of my friends (one who has NO mechanical skills at all) I’m pretty confident when I say anyone can build their own electric cars.

After all, the reasons for doing a conversion far outweigh those for not doing one. With the price of gas going up, it is much cheaper to power things with electricity. For example, my friend used to spend around $150 per month on gas and now he spends roughly $30 per month to charge his car every night. Pretty amazing savings isn’t it? He managed to pay for the conversion in less than 4 months.

The parts for our electric car weren’t very hard to find. For the electric motor the guide suggested we go looking on eBay where we found one for about $65. We decided to try and cram 14 deep cycle 12 volt batteries in there as well. We got those for free (the guide shows you how to find free batteries) which ended up saving us well over $1400. The assorted nuts, bolts and electronics cost just over $200 so all in all we ended up paying roughly $350 to build our electric car.

The plans were so good that the only thing we really had trouble with was hoisting the old motor out of the car. This wasn’t actually as hard as it sounds because the motor is only attached by a couple bolts and once they’re loose it comes right out.

I am very satisfied with how it all turned out. We drive a zero emissions vehicle and it doesn’t cost us anything (we live on renewable energy). For our friends who are still hooked up to the grid it only costs them about $30 per month to drive… which saves them $110 per month or $1320 per year! I just love pulling up beside people at a stop light and not making a sound. Since the car has an electric motor we also have a lot of low end torque, which means that I can pretty much beat any car in acceleration, and being able to go 50 MPH means I can still drive on the highways.

Cool Fast Cars And Performance Vehicles

In the world of fast and mean machines we often find a few brand names which catch our attention due to their reputation, style and price tags. European cars are most of the time the ones who take the all the glory due to their extreme attention to detail, speed and power; some have even said that the only thing some of the fastest cars are lacking, are wings. With so much horse power it wouldn’t be surprising to hear one of those cars went airborne.

While some of the most powerful and fastest cars are fairly new, some movies such as the fast and the furious have brought sexy back through some old and powerful models, that is the case of the fully tweaked 1970 Dodge Charger, the 1965 Ford Mustang, 1965 Shelby Cobra Daytona, the 1971 Chevrolet Monte Carlo, 1970 Plymouth Roadrunner GTX, etc. These classic cars are surely attention grabbers since their original design is really unique compared to most modern cars.

Among the newest models featured in such film we have the fully customized 2003 Honda Accord, the 2005 Ford GT, 2005 Shelby GT500, 2006 Mazda RX-8, the 2005 Dodge Viper SRT10, the 2003 Nissan Fairlady, the 2005 model APR Mitubishi Lancer Evolution VIII MR, etc.

There are several categories each car performs best at, so we can’t compare them all on a 1 to 1 scale, some are faster, others have more control, others are better for drifting, etc. In speed competition we can compare the acceleration times until each model reaches 60MPH, and these are the results:

To go from 0-60 the following models make 4.9 seconds: 1996 Ferrari F 355 Berlinetta, 2002 Acura NSX, etc.
The 2000 Porsche 911 Turbo and the 2003 Dodge Viper SRT-10 are tied on 3.8 seconds.
The 2002 Ferrari Enzo and the 2002 Pagani Zonda C12-S 7.3 are also tied on 3.5 seconds.
The 2003 Bugatti 16/4 Veyron reaches 60 MPH in just 3 seconds.
And to top them all the 1994 Dauer 962 LeMans reaches 60 MPH in just 2.6 seconds!, how is that for a fast car?

Fast cars attract a very specific young group of people but for those who prefer style and sleek lines, there are newer models which have been released to the market fairly recently, these are the so called “Eye Candy” models:

The 2008 Porsche Chayenne which features the brand new TechArt Aero Kit, this stylish SUV. Another sleek car which was made famous by one of 007 movies “Casino Royale” is the Aston Martin. There are so many cars which would fall in this category a full blown blog is necessary!. Cars are part of the American culture but wherever you are, if your culture doesn’t involve cool fast cars, believe me, it will soon.