Ask Joe Mechanic - Automatic Transmission Servicing

Last week we examined the idea of performing an engine flush and found that in most cases, it is not a recommended procedure. When it comes to transmission flushing, the opposite opinion is true. Most technicians will tell you that a properly performed transmission flush will prolong the life of a transmission, and in some cases, even cure some early signs of a transmission problem such as minor slipping on pullout or sluggish upshifting.

            The first type of transmission maintenance is the basic fluid level check on cars with a dipstick. Most cars need to be checked with the engine warm and running with the transmission in park. The reason for the engine and trans being warm is because transmission fluid expands as the temperature increases. Check either on your dipstick or in the owners’ manual as to the instructions for your vehicle as some cars need to be checked in neutral, and Hondas need to be checked with the engine shut off. There are two important things to observe when you check your fluid. The first, of course is the proper fluid level, which should be at or very close to the full mark. If near or below the add mark, you need to add the appropriate type fluid for your vehicle. Also observe the color and condition of the transmission fluid. It should be a reddish color and it may have some small bits of black particles in it as the clutches wear. If the fluid is brown, smells burned, or has metallic particles in it, these are signs of problems.

            One of the things to know on late model vehicles is that in many cases the manufacturer no longer installs a transmission dipstick, leaving some people to believe that the transmission no longer requires regular maintenance. This is actually quite false. While some vehicles have a sensor, which will indicator trans fluid condition and level on the info display similar to an engine oil indicator, others give no indication. It is true that synthetic trans fluid lasts longer than the older traditional fluids, it still will break down and become contaminated over time and should be changed. Therefore, trans fluid checking and servicing has now basically become a dealer controlled maintenance item unless you are able to locate the fill level plug to check it.

            Ultimately, your owners manual will tell you what transmission servicing is recommended for your vehicle. It will give you a schedule of recommended fluid changes, often between every 24,000 to 36,000 miles. If a transmission flush is recommended, it will probably range between 60,000 and 100,000 miles, while some manufacturers will not recommend flushing at all.

            Opinions vary greatly as to whether or not this process is necessary for proper vehicle maintenance.  Yes, flushing a transmission assists in removing dirt from the torque converter, valve body, trans cooler and cooler lines, but is it really beneficial to an engine?  An article on Wisegeek.com reflects that some automotive professionals report that regular flushing assist with better working and longer last transmissions.  However, the same article notes that many feel that flushes are unnecessary and can damage a vehicle’s valves and seals.

On most vehicles, it is still possible for a mechanically inclined person to do a fluid and filter change, and this is definitely better than no servicing at all. The first thing you should do is to either pull your vehicle up on servicing ramps or jack the vehicle up and place it securely on jack stands. If there is a drain plug, remove the plug and drain into an appropriate drain pan. If no plug is present, or after draining, carefully unbolt and remove the transmission pan, allowing it to drain into your drain pan. Look in the bottom of the pan to see if there is any dirt, sludge or metallic particles. A presence of large amounts of deposits is a sign of developing problems. Clean the inside of the pan, remove the old gasket and set aside. Now remove the filter, more fluid should now drain out of the valve body, and dispose of the old filter. Install a new filter, a new gasket and reinstall the pan. Estimate how many quarts of fluid that you have drained and add slightly less than that amount. Lower the car to the ground, start the engine and run until warm. Move the shift selector through all positions and place back in park. Check your fluid and add as necessary to bring up to the proper level. Drive the car about fifteen minutes and then recheck and add fluid if needed. While this process does not remove all the fluid from the transmission, it does serve as a great benefit.

When using a transmission flushing machine, more of the old fluid is removed, and the overall transmission system is cleaned. This means that there is less dirt and old fluid to contaminate and weaken the new fluid. In some cases, a special transmission flushing chemical is added to help clean the system before the new transmission fluid is added. The fresh transmission fluid means that the transmission should run cooler and more efficiently, thereby prolonging the life of the transmission.

The only way a transmission flushing machine will damage your transmission is if a high pressure back-flush type machine is used to force fluid backward through the transmission. This type of flushing system is hardly used anymore. In most cases, a transmission flush does not rely on pressure to flush out the residue of the old fluid. Instead, the transmission's pump or a machine is used to gently circulate the new fluid through the system either by connecting directly to the transmission pump or into the transmission cooler lines and follows its normal path of circulation. This means that rather than applying pressure that could damage the transmission, simple replacement is used to rid the system of most of the old fluid.

There are two slight drawbacks to the systems that connect to the transmission cooler lines. First, is that unlike the normal transmission circulation path, this pushes all the fluid through the lower pressure regulator which controls the internal system of the transmission, it will not direct fluid through the higher pressure regulator to the torque convertor. This means that there will still be some old fluid left in the system which will somewhat dilute the new fluid. The other issue is that by not removing the pan, the filter will not get changed unless you request it, and the technician will not have the opportunity to examine the inside of the pan.

In general, periodic transmission flushes are a good idea, no matter which of the two current types of machines is used. But, there is one time that you definitely should not do a transmission flush. If the fluid has a severely burned smell or there is a collection of metallic particles on the dipstick, your transmission has internal part damage and is probably very close to failing. Your transmission just has not figured out that it should die yet, but if you flush it, it will most likely fail almost immediately. Save your money for a replacement transmission, because at some time, probably in the near future, you will need one. This is one of the major reasons why you would want a transmission flush to be performed by a qualified professional.

Portions of this article were sourced from the Transmission Flushing article featured on www.wisegeek.com. 

Ask Joe Mechanic - Engine Flushing

A hotly debated subject is engine flushing and whether it is beneficial or it is actually harmful to an engine. No two technicians seem to agree as to whether you should perform this service on your vehicle.    

The process of engine flushing is used to clean sludge, dirt and deposits that build up in the internal parts of an engine, especially inside the valve cover and the oil pan over time. The main purpose of performing an engine flush is to try to extend the life of the engine. By flushing an engine periodically, the inside of the engine will hopefully stay relatively clean and will operate more efficiently. 

The method used to flush an engine is somewhat like what is used to flush a transmission. When flushing a transmission, the fluid is pushed through the transmission to carry the old fluid and dirt and deposits out of the transmission by way of the drain plug. With engine flushing, a cleaning chemical is added to the engine oil and circulates through the lubrication system. The chemicals eat away at the deposits, eventually making their way into the oil pan, where they collect in the bottom of the pan to allow it to be drained.

While the theory behind flushing an engine seems like something that should be done on a periodic basis, there is much disagreement as to whether it is smart and effective to do. While it is general knowledge that it can be beneficial in low mileage vehicles that have not had proper maintenance performed, something that is often found to happen in lease vehicles where the leasee feels that it is not my vehicle and I am giving it back in two or three years, so why worry about changing oil and spending that extra money. Many technicians question whether it is a good idea in higher mileage vehicles. There is the chance in an older engine that the buildup of sludge may be more than the chemicals in the flush can properly loosen and remove, which could worsen a bad situation. Another fear is that the sludge will lie in the pan and clog the oil pump pickup screen and cause oil starvation. Instead of performing an engine flush, it is much more effective to disassemble and clean the engine as long as it is in good operating condition, even though this is more expensive, or else do a complete engine rebuild if it is determined that the engine is not in good condition. 

Because there is such a difference of opinion whether to do an engine flush or not, not every garage offers or recommends this service. Some facilities that used to do engine flushes, including a dealer where I used to work, no longer do so. Even in shops that do engine flushes, they will generally have a technician check the condition of the engine before they will do the flush. 

It is important to remember that there is no substitute for proper maintenance. If anything, an engine flush should be considered as a way to supplement the proper care of the engine and thereby help to prolong its life. Also, if you do choose to perform this service, I recommend having a professional do it and seek their advice first, I do not consider this a wise do it yourself procedure.

Ask Joe Mechanic - Interior Car Care

            There are quite a number of things that you can do to prolong the life and maintain the beauty of the interior of your vehicle. Most of these things just take some time and effort and do not cost a lot of money.

            First of all, it is important periodically vacuum your interior. Do not just do your carpets, as running the vacuum over your seats will never hurt them. Also be sure to go under and alongside the seats and any other cavities that you can reach. And always do your trunk area.

            As far as your seats and any other upholstered areas, if it is cloth, after vacuuming, if the material is soiled, a good upholstery or carpet cleaner can be used. A product like Resolve foaming cleaner can be used and be sure to follow the manufacturer’s instructions. The same thing can be done to clean your carpets and carpeted floor mats. This method may also be used on your headliner if it is dirty.

You can then, if you so choose, apply a Scotchguard treatment for ease of future cleaning. If you seating is vinyl or leather, you could use a mild dish soap and warm water solution with a soft cloth or brush if more heavily soiled. After cleaning, apply a good quality automotive leather protectant, but use sparingly so as to not make the leather too slippery or sticky.

            You should also use that mild soap and water to wipe down the top of your dash and your door panels and console, but make sure you ring your rag out well and do not wipe over any switches or electronics. Electronic screens such as radios and navigation or DVD player screens should be cleaned with an approved electronic spray screen cleaner.

After wiping down your dash and door panels, apply a protectant such as Armor-all, but definitely do not use it on your steering wheel or seats, as it is much too slippery.

            To keep your car smelling fresh, you can use the good old standard, the “Pine Tree” air fresheners. However, I personally like the small air fresheners that can be inserted into the dashboard vents.

            Spending a few hours a couple times on these car care tasks a year can really pay off in keeping your interior looking good, just like the day you bought it. See you next week.