- 1965 speedometer reading too fast
- Speedometer gear change (up teeth or down)?
- Speedometer Adjustment- 10 MPH too fast. Easy or Difficult Fix?
- 1965 speedometer reading too fast
- Mechanical Speedometer Calibration - Speedo Demons
1965 speedometer reading too fastThere can be multiple reasons for the speedometer to malfunction, and replacement need not be the only solution. Here, we have tried to provide likely issues that can occur with the speedometer, along with troubleshooting tips for the same. Before the invention of the speed gun, cars in the early 20th century were required to have two speedometers, one on the dashboard and one on the front fender, so that police could see how fast they were going! A speedometer is an instrument which provides the driver with instantaneous readings of speed. Traditional speedometers used gears and wires to determine speed, while most modern vehicles use speed sensors for the same. Common problems include, a faulty sensor, bad wiring, or dial malfunctions. Troubleshooting speedometer problems mostly call for a replacement of the speed sensor or cable, depending upon the vehicle. Both these repair jobs are simple to perform and can be done at home. Would you like to write for us? Well, we're looking for good writers who want to spread the word. Get in touch with us and we'll talk This could be due to two reasons. In older cars a break in the cable that connects the transmission to the speedometer is the most common cause. Cars produced after are usually equipped with speed sensors, which may crash and cease to transmit speed readings to the speedometer. A more serious problem could be a faulty speedometer head, which needs expert diagnosis. If cruise control is working, and the check engine light is on, it may indicate a problem with the speedometer itself, and may require a change of the instrument panel. In cases where the speedometer does not settle on any particular reading but keeps moving between speeds, it is almost always due to bad wiring, in case of a cable system, or a faulty speed sensor. In most cases, only the wiring needs to be changed, or the sensors re-calibrated, to repair the problem. Speedometers are calibrated according to the radius and diameters of the factory-fitted tires of your car. These determinants can change, if you get custom tires which are larger, or if they are of different dimensions. The rate at which your tires cover ground changes and if the speedometer is not calibrated accordingly, it can show a faulty reading. You will see a thick black wire leading into the instrument cluster, this is the speedometer cable. Remove the clamps present on the transmission and engine compartment that hold the cable in place. In the adapter, fix the square end of the new cable and also tighten the nut on the rotating shaft. Then, twist the sensor to take it out. Reattach the hose, air cleaner and electrical connector on to the sensor. Attach the electrical connector to it, and tighten it. Not every speedometer related problem needs a replacement job. It depends on the cause. In case the dial is the problem, you can easily replace the dial alone. Problems with the inbuilt computer will require replacement. It is therefore important to take your car to a mechanic and run a full diagnostic test, before jumping to any conclusions and attempting self-repairs. Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Speedometer gear change (up teeth or down)?
The speedometer is an important part of the car engine as it indicates the speed of your vehicle while on the road. A faulty speedometer can cause major driving issues, which can lead to speed-related accidents or an unnecessary speeding ticket from the police. As with any brand of vehicle, Ford vehicles are susceptible to speedometer problems. The PSOM includes the odometer and the speedometer, which are electronically controlled by a programmable microprocessor. The module works by receiving speed signals from the Differential Speed Sensor DSS and converts the signal input to the standard 8, pulses per mile output. The most common issues with the Ford speedometer are when it bounces back and forth continuously while the vehicle is being driven. Another problem that might arise is when the speedometer doesn't move at all. This indicates that the car's speedometer is dead. Speedometer issues typically occur when major changes are made to the Ford vehicle. These include changing fuel types from diesel to unleaded gasoline for exampleand changing tires, as the vehicle's speed performance varies depending upon these two aspects. It is not uncommon then for you to experience a faulty speedometer after having had your tires changed, for example. The conversion constant needed to calculate your instantaneous speed is different and has yet to be determined. If you think you are having problems with your Ford speedometer because of tire or fuel changes, the the best way to solve it is by resetting the PSOM. You can do this by pressing the SELECT button found on the upper right corner of the speedometer, then you select zero for the trip odometer. It is also a must to change the speedometer's internal conversion constant if you have changed tire sizes because this will enable your speedometer to calculate your speed accurately. Because the Ford speedometer is equipped in a full-device module, the only way to fix a broken speedometer is by complete replacement. The PSOM devices can be quite expensive because of their computer parts. Hence, it is important check out your speedometer's performance as well as the odometer calculations and provide the right conversion constants so that they will not only be able to provide correct calculations, but also avoid incompatibility problems with any new changes made to the vehicle. This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us. Ford Speedometer Problems by WilliamHanz. Causees Speedometer issues typically occur when major changes are made to the Ford vehicle. Troubleshooting If you think you are having problems with your Ford speedometer because of tire or fuel changes, the the best way to solve it is by resetting the PSOM. Repair Because the Ford speedometer is equipped in a full-device module, the only way to fix a broken speedometer is by complete replacement. References Speedometer Problems. About the Author This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. Photo Credits Image by Flickr.
Speedometer Adjustment- 10 MPH too fast. Easy or Difficult Fix?
If you drive your hot rod, even once in a while, then you depend on all of your gauges to be reliable and accurate. Just a small percentage of miscalibration can result in engine damage or failure, overheating, or just running out of gas. Driving around with an incorrect speedometer can be dangerous and could earn you a ticket-not to mention the constant reminder that an important part of your rod or custom just isn't operating the way it should. We don't know how many of you are driving around out there with inaccurate speedometers, but considering that almost every one of you has probably changed your tire and wheel combination or your rearend gears sometime in the past, it's probably a pretty high percentage. We take it for granted that a speedometer measures vehicle speed, but technically, the speedometer measures the number of driveshaft revolutions per mile, which is displayed on the gauge face as speed in miles per hour. When you change the tire height or the rearend ratio, you change the ratio between the number of driveshaft rotations during one complete tire rotation, which changes the number of driveshaft revolutions per mile. The speedometer reading has to be corrected to reflect the change. Taller tires will cause the speedometer to indicate too slow a speed, and shorter tires will cause it to indicate too fast. Similarly, taller gears lower numerically will have the same effect as taller tires, and the speedometer reading will be slower than actual. In either case, you need to figure out the amount of error in your speedometer and how to correct it. How Off Are You? A simple seat-of-the-pants method for figuring out the accuracy of your speedometer is to find an open stretch of highway, preferably one with mile markers. If there are no mile markers, you can measure the distance of one mile with a vehicle that you know has an accurate speedo. Maintaining a constant speed, get a passenger to calculate the time between mile markers using a stopwatch. Divide 3, by the elapsed time in seconds that it took to go one mile and that'll give you your actual speed. For example, say you made your one-mile run at a speedometer reading of 60 mph, and your one-mile elapsed time was 50 seconds. Dividing 3, by 50 equals your actual speed of 72 mph. You already know that going 72 mph when you think you're going 60 could earn you a speeding ticket. Dividing the actual speed by the speedometer reading will tell you the percentage of error. In this case, 72 divided by 60 equals 1. As you may have figured, this method, even with all the arithmetic involved, is far from precise. Stopping and starting a stopwatch at exactly the right moment, and maintaining a perfectly constant speed for a mile, is difficult. But this will put you within the margin of error for mechanical speedometers. Mechanical Speedo Calibration On a typical mechanical speedometer, the gauge is operated by a flexible cable running from the transmission. The transmission output shaft drives the cable via a pair of nylon gears. The drive gear is a worm gear located in the transmission, running off the output shaft. It turns the driven gear, a pinion gear that is connected to the end of the speedometer cable. Changing the ratio between the drive gear and the driven gear will change the speedometer reading. A driven gear with fewer teeth will speed up the speedometer reading; more teeth will slow down the reading. On the drive gear, it's the opposite-fewer teeth will slow down the reading and more teeth will speed up the reading. Generally, it's easier to change the driven gear at the end of the cable than to dig the drive gear out of the transmission housing. So going back to the earlier scenario where the speedo is reading 60 mph but your actual speed is 72 mph, the situation can be remedied by swapping the driven gear for one with fewer teeth.
1965 speedometer reading too fast