How to Service Your Transmission – Things Your Transmission Shop Wished You Knew (Part 1)

Each year automobiles continue to get more complicated. There was a time when it was common (and fairly easy) to maintain and repair your own vehicle. Today, the increased sophistication of your vehicle’s various systems, especially the electrical components internal to transmissions, makes it hard to stay on top of the good maintenance required to increase the life expectancy and continued performance of your vehicle. As we have discussed before, your transmission is one of the most complicated systems in your vehicle.

A responsible vehicle owner needs to be well informed on major vehicle components including transmissions, transfer cases, and differentials. The Advanced Transmission Center team has been the preferred local transmission shop in Denver since 1986 and has some lessons learned we would love for responsible vehicle owners to keep in mind when considering how to service your transmission. Being more knowledgeable won’t eliminate repair costs but it can mitigate the risk of a severe failure. After all, a transmission is a wearable component so its ultimate failure should be expected. Keeping the following things in mind will help you be a better vehicle owner:

1. Transmission Fluid LEVEL Must Be Monitored Regularly

Transmission fluid is the lifeblood of that component and critical to keeping it running efficiently. Transmission fluid is used to lubricate your transmission and essential for it to run smoothly. It is also a hydraulic fluid that allows mechanic movement of parts that change internal gears. Moreover, it cleans and protects the metal surfaces inside the transmission and helps condition gaskets. The transmission fluid also helps with rotational speed and managing temperature by acting as a coolant. When the fluid is low, it is not able to provide the protection it should, and internal damage is not far behind. A low fluid condition means less volume of liquid to disperse heat generated from the operations of the transmission. As for how to check the fluid level, make sure you read your owner’s manual. For most vehicles, the transmission fluid level should be checked when the car is warmed up and on a level surface. Some vehicles require checking the fluid level while in gear, and some require checking while in neutral (typical among many Chrysler/Dodge models). Additionally, some vehicles do not have a dipstick and require pulling a plug to check the level. If you do not know how to check the fluid level yourself, make sure you work with a local transmission repair shop that can confidently check it on a regular basis.

2. Transmission Fluid Degrades and Regular Services are Necessary

While it is handy to have rules of thumb to make sure you do not abuse your transmission, no one can say for sure that your vehicle is going to be exactly like every other of the same make and model. Differences in driving style, road conditions, highway vs. stop-and-go, etc. all make each vehicle a little bit different. The only way you can be sure that you are staying on top of the need to change your transmission fluid is to look at it on a regular basis. Most transmission fluid is a very bright red color (there are exceptions, but these are rarely seen in standard vehicle applications). When it begins to become a darker reddish-brown, it is time for a transmission service. Would you delay an oil change for multiple years? As much as that sounds silly, plenty of vehicle owners avoid transmission services and increase the likelihood of a catastrophic and costly failure of this component.

Every manufacturer has guidelines for your vehicle’s maintenance schedule. Replacing transmission fluid should be expected but experts will have differing opinions. More frequent transmission service from a qualified transmission specialist will minimize the risk of costly repairs while avoiding a service will dramatically increase the chance of failure. Especially as vehicles get older and there is more mileage wear on the transmission, it is just not possible to say that you are going to get 30-40,000 miles between service. Staying on top of this is going to increase the life of your transmission, and your vehicle will thank you for it!

3. A Transmission Service Will Not Fix Existing Problems…And Could Make Things Worse!

Imagine being on the way to work and realizing your transmission is slipping and/or changing gears harshly. When you step on the gas, the engine revs but you aren’t going any faster. As you eventually shift, it feels erratic with harsh engagements. You ask a friend what you should do, and they say, “you need to go get a transmission service and have the fluid changed.” That sounds reasonable, but IT IS TERRIBLE ADVICE. Slipping and inconsistent shifts are signs there is internal damage within the transmission, and a service is not going to fix that. Whether there is a mechanical failure or electronic malfunction, changing the fluid will not address the underlying issue. Additionally, putting new transmission fluid into a transmission that is having problems can accelerate the internal wear and failure, especially if the symptom is the result of worn clutches. It might seem like a cheap way to keep your vehicle going, but it is likely a waste of money and could increase the eventual cost of a transmission rebuild. Where it might have only needed the soft parts (the clutch packs, seals, o-rings and gaskets that are wearable components) replaced, you may now have to replace hard parts that have failed because of the additional stress of operating in excess heat and friction. If you begin to have transmission trouble, get it to a competent transmission shop and let them inspect it properly! The team at Advanced Transmission Center recommends our free TrueTest InspectionTM to accurately diagnose the issue.

4. Your PTU/Transfer Case and Differential Need Regular Servicing

There is more to your vehicle’s drivetrain than just a transmission. In the case of a front wheel drive vehicle, you have a PTU and in a 4-wheel drive vehicle, you have a transfer case. All vehicles have at least one differential. These “gear boxes” are designed to transfer the power from the transmission to the appropriate axles. While they are a critical part of your vehicle’s operation, they are also the most ignored part of the driveline. They are robust and complex components that require the fluid be checked on a regular basis and replaced at regular intervals. Many “quick lube” type service centers don’t have the tools necessary to check these parts and don’t include them in their multi-point inspections. Fluid leaks in these units are usually slow and don’t leave puddles, but instead build up a layer of grime on the outside of the case. Unless you happen to poke your head under the vehicle to look for it specifically, you may never know the unit is leaking. And once a low fluid level condition is present, that unit will overheat in a short period of time and fail. Rather than trust your car to the cheapest option, make it a point to take your vehicle to a competent transmission and driveline specialty shop for routine maintenance. You could pay a little more for their expertise, but it will save you a LOT in the long run!

5. Vibrations, Noises and Leaks Should Be Diagnosed IMMEDIATELY

We get it…life can be hectic. You live in a stressful world, and the last thing you need on your plate is a problem with your vehicle. You know your truck, car, or SUV better than anyone, and you know quickly when things are not working the way they should. Something may feel off even if you cannot pinpoint the issue or you feel a vibration while driving. You hear a whine or a clunk that wasn’t there before. Or you notice that there is a small puddle under your vehicle when you back out of your driveway. And because your life is busy, you decide to put it off for a while until it is convenient to deal with it. We understand that there is no convenient time to bring your vehicle in for repair, but keep in mind the cost of those repairs is climbing the longer you ignore the warning signs. In many cases, getting your vehicle in as soon as you notice something out of place can mean a very simple and inexpensive repair. That simple leak caught early might mean a simple gasket replacement, where waiting until the fluid has gotten too low and resulted in overheating can require a full transmission rebuild that can cost thousands of dollars. The knocking you heard might be a sign of a low fluid condition that could have been fixed by adding a couple of quarts of fluid but waiting results in internal failure that might mean replacing an entire transfer case or differential. In short, don’t wait! Get your vehicle in as soon as possible when you notice something out of place.

6. Your Tires Are More Important Than You Know

You have probably heard at some point that when you replace a tire, you need to replace two. For a 2-wheel drive vehicle, this is true, across the same axle. The reason is that your differential allows different rates of speed of the tires and wheels from side-to-side during turns, and still allows the vehicle to drive smoothly. When your tires are the same size, the differential has an easy life as the internal gears do not do any work unless there is a difference in rotational speed, most prominent during turning. If you only replace one tire, it will not be the same tread depth and circumference because one will be worn while the other one is new. With two different size tires there is a difference in speed even going straight down the road. This will over-work the differential and harm it quickly. In a 4-wheel drive or an all-wheel drive, it is necessary to replace all four tires at the same time. All four tires need to be of the same size, tread pattern, and tread depth. All-wheel drive vehicles send power to all four wheels at different proportions to the axle. Four-wheel drive can have the power distribution selected by the driver or automatically applied when needed. These vehicles may have a center differential to regulate speed differences from front to rear and conventional differentials for side-to-side differential action, making universal tire size important. Regardless of the vehicle, running different size or different tread type tires will result in excessive wear and tear on the drivetrain. In cold weather states, the same principle applies to winter tires. The money you saved on tires will pale in comparison to the money you are going to have to spend on driveline repair!

Stay Tuned for Part Two…

If you need service or are having problems with your transmission, transfer case or differential, contact Advanced Transmission Center at either of our locations and we’d be happy to help! Unlike dealerships or many independent repair shops, we are transmission specialists trained to fix issues related to a vehicle’s drivetrain. You can reach out to either location that is most convenient for you.

Please call our Westminster (Northwest Denver) location at (303) 421-4140, our Lakewood (Southwest Denver) location at (303) 922-4102 or contact us online to get started today! We look forward to serving your vehicle drivetrain and transmission needs. Over 35 years, our goal remains to be “Geared for Customer Satisfaction!”

Written by Advanced Transmission Center