Automatic and Automated Transmission

July 30, 2014 admin Leave a comment

These two terms, when it comes to transmissions, are often used interchangeably, which is false. Automatic transmission and automated manual transmissions are completely different types of equipment. The most critical difference is the automatic transmission uses a torque convertor rather than a typical two-plate manually activated clutch. Here are some key similarities and differences that any driver should be aware of.

One of the big differences between an automated and automatic transmission is that automatic transmissions use the same set of gears to produce all of the different gear ratios. A planetary gearset makes this function possible.

Rather than a traditional gearshift as in the case of a manual transmission, the ratios in a planetary gear rotate, driven through a set of clutches that make the planetary ratios change.

This then becomes a gear shift, but because the input shaft passes through a hydraulic torque converter, the engine does not have to decelerate during a gear change. The engine turns a turbine inside the torque convertor housing at the front of the transmission. The torque is then transmitted through the planetary gears to the output shaft, which drives the wheels.

The gear ratios are actually determined by the number of teeth on the gears inside the planetary gears, and which of those gears is actually in use. Automatics are also used in heavy trucks, which typically have five to six forward speeds, and one reverse speed.

Automated transmissions are a standard manual gearbox with electrical servos that automatically execute gear changes and manage the clutch. Beyond the electric control and actuation of the gear changes, the manual is not much different from its fully manual siblings.

The manual transmission engages and disengages different sets of gears on two countershafts linked to the output shaft to create various gear ratios.

The gear steps are more or less equally spaced to improve the predictability of a gear change for the driver. Multi speed manuals such as 13 and 18 speed models have a close gear step to permit better matching of engine to road speed. Generally, North American manuals have 8-18 gear ratios, plus a two or three range reverse gear.

If you have any questions regarding both automatic and automated transmissions, and simply just transmissions in general, call Grisham Transmission today. With over several years in the transmission industry, they have the required experience it takes to tackle any transmission or car problem. Contact them today at 615-226-2789.

Transmission Repair Guide

July 30, 2014 admin Leave a comment

It really stinks when you have to repair a certain part of your vehicle when it breaks. Probably one of the most difficult to repair is the transmission, as there is no other part of the engine that is more complex. The transmission is responsible for shifting gears to quickly change the speed to torque ratio in order to deliver power to your wheels, allowing your car to move.

Finding the symptoms of your car problems can be tricky, but regularly changing your car’s transmission fluid or getting the transmission flushed will mitigate the damage or just get rid of any problems you are having all together. Some of the signs to look for are the transmission slipping in between gears while driving or popping back to neutral. There may be an unusual grinding or clunking nose, so be mindful of that. Your clutch may also be dragging, which means the clutch is staying engaged and causing grinding noises when trying to shift.

If your transmission does begin to fail in some shape or form, or just simply stops working, mechanics will usually recommend a replacement or some amount of repairs. Each type of repair has different procedures and costs associated with it. If problems are caught earlier than later, you will find that the minor repairs are much more budget friendly as they usually do not require complete removal or disassembling or replacement of hard parts.

There are several factors that play into how much your transmission repair could cost. The make or model of the vehicle is very important. If the transmission needs to be replaced or rebuilt, you can expect to pay several thousand for parts and for the skilled labor, while minor repairs and a fluid change can cost less than a couple of hundred dollars.

The extent of the damage also plays into how much the repair will cost. What type of conditions the car has been through can also affect the price, as newer cars that have been well maintained will cost less than those that have been through tougher times.

The driver’s location contributes greatly to the overall cost of the procedure. Areas that have a higher cost of living, higher demand of services, or lower availability of skilled technicians will charger even more for labor costs, which will increase the overall price. Call Grisham’s Transmission Center today for more information at 615-226-2789.

How To Diagnose Your Automatic Transmission Problem

June 20, 2014 admin Leave a comment

For a person who isn’t car-savvy, the transmission is undoubtedly the most difficult to understand. There are so many different parts to it, it feels impossible to decipher what may be wrong with it when it’s not working properly. Here are some ways in which you can try to find out what exactly the problem is with your transmission.

There are two groups of problems that are caused by the exact same faults in your transmission, so whichever your car happens to be doing, the following applies.

It is extremely important to check your transmission fluid at least twice a year. Not only can a low fluid level cause your car to shift poorly, it can lead to some very serious damage and an incredibly costly repair, something we are trying to mitigate here. If your car seems to be losing an excessive amount of fluid, you most likely have some type of leak.

Checking for a leak isn’t as bad as you think it is. Understand that the transmission is a closed system, so there are a limited amount of places that your car can leak from. Unless your transmission fluid has been changed to a neutral fluid, your car should have red transmission fluid.

Here are the several places that you need to check for a potential leak: At the filler tube base, at the drain hole under the transmission, between the transmission and the engine, at the selector shaft, under the speed sensor mounting point, or on the radiator. The selector shaft is the rod that connects the gear shift to the transmission. The speed sensor mounting point can either be a cable screwed into your transmission machine, or an actual sensor that is just bolted in. If your car has a transmission cooler, it is likely that the transmission fluid will leak into the radiator fluid. These two fluids don’t particularly mix well, so you’ll probably find it sitting there.

Another common problem that people have is that their filter is clogged. If you haven’t replaced your filter in a while, be sure to do this, as this is a very common problem that people don’t troubleshoot before the go spend a fortune at the car mechanic.

Unfortunately, most transmission problems can’t be done by yourself, as there are so many specialized tools to fix so many different issues. Do not worry though, as Grisham’s Transmission will fix whatever problem you are having for an affordable price. Call today at 615-226-2879.

How To Identify Your Brake Problem

May 21, 2014 admin 6 Comments

Having a properly functioning car is absolutely critical in this day and age. Getting yourself from place to place on time without problems allows for a flexible lifestyle with various activities. If your car is having problems, especially brake problems, you won’t be getting anywhere until you fix them. Here are some of the ways in which you can diagnose your brake problems and take the right steps to fixing them.

As mentioned above, the first step of properly fixing your brakes is determining what exactly your problem is. Turn off your car engine and slowly let off the brakes. If they feel like they are mushy or soft, you might be low on brake fluid.

If you’re driving at low speeds, try braking if it is safe. If you hear a squealing noise, your brake pads might be the issue. Consider replacing or even just cleaning them. In a safe area such as an empty parking lot, try sharply pressing on the brakes. If your car fails to brake properly, you may have worn pads, or need to decontaminate you brake fluid and pads.

If you’re finding that when you break your car is being pulled to one side, you might need to adjust the brake’s clearance. Not only may the problem just be the clearance, but also you could potentially have to replace the pads and rotors, or have insufficient hydraulic pressure in part of the brake system.

While driving slowly, pay attention to if the brakes drag behind or bind, because this might be a situation in which grease may be present on the pads or rotors. If your brakes are making a grinding noise, be sure to check the lining and surface of the brake, as there may be some potentially severe damage to both parts. Look for a seized or even partially seized brake, because this can cause premature and uneven brake wear, significantly shortening the life of your brakes.

If the pedal feels firm but lacks the proper amount of stopping power to slam on the brakes, check the operation of the brake booster and also the check valve. If there are any parts that are damaged or destroyed, be sure to replace them. Look for any hydraulic parts that are contaminated or damaged, and clean and potentially replace them as well.

If you find that your brakes are producing a burning odor, check for rust in places such as the brake caliper or the caliper piston. If there is no problem with rusting, be sure to take a look at the parking brake. If damaged in any way, consider investing in a repair job.

When looking for a repair job for your brakes, nobody does it better than Grisham’s Transmission. Located in Nashville, Grisham’s has experts with years of experience ready to fix not only brake problems, but also axels, clutches, auto, standard, flywheels, starters, and much more. Call today at 615-226-2789.