Your vehicle’s transmission is a vital part of operation. Without it, your car won’t go.
If your transmission has problems, it can be a safety hazard. Imagine getting in a situation where your car won’t change gears, or suddenly does as you’re driving down the road.
When you notice a transmission problem, a mechanic will inspect it and find what’s causing the issue. It might be a minor repair, or it could be more serious. That’s when you’re likely to have to make a decision: should you consider a transmission rebuild, or is it time for a new one.
Understanding a transmission
Think of a transmission as a car’s gearbox. If you compare it to a bicycle, it would consist of a gear shifter and chain mechanism.
The transmission components are mounted to the engine compartment so the gear and chain system can effectively convert combustion power from the engine into physical energy.
Fuel is ignited in the combustion chamber. As fuel ignites, it uses the heat to push pistons up and down in the engine cylinder, spinning the crankshaft. This crankshaft is what’s used to move the wheels.

It’s the transmission system’s job to ensure this energy force is kept under control. The transmission ensures energy is sent to the wheels at intermittent levels, depending on the speed you’re traveling at. Without it, it would be difficult to start and stop your car.
A transmission changes gears as the vehicle moves through different speeds. As you push down on the accelerator, let up and apply the brake, the transmission adjusts so that the engine’s revolutions per minute (RPMs) are kept relatively low. This provides better fuel consumption, and ensures the energy process doesn’t overload the engine. Think of it as a harnesser of energy, making the entire process work safely and efficiently.
Everything works well. Until it doesn’t.
What is a rebuilt transmission?
Transmissions are one of the most complex systems that make your vehicle operate. When something goes wrong with the transmission system, the repair process can escalate fast.
While mechanics will speak of a transmission as if it were one part, it’s actually a series of over 800 different components, each with its own unique make and model. Each part can be repaired or replaced. It’s a time-consuming and expensive process. Even for a highly trained mechanic, it takes time to ensure the right pieces are fixed, and the entire system is efficient once it’s put back together.
Inside a transmission are several major components:
- Gear set – this allows the forward and backward motion.
- Hydraulic system – transmission fluid moves through the system to help control gear movement. It helps with lubrication, cooling, and shift control.
- Seals and gaskets – these components ensure lubricant stays where it’s supposed to be without leaking.
- Pump and turbine – the engine and transmission work through a series of three fans, spinning as fluid is pushed through the system.
- Throttle cable – this monitors speed and throttle position of the transmission to help determine the proper time to shirt.
- Computer – modern day vehicles use a computer to control the process through a series of sensors.
A transmission rebuild would include working on any one or more of these components. If any part is damaged or worn out, the components would be in need of repair. It includes replacing a series of parts rather than replacing the entire transmission.
Rebuilt transmissions can involve major overhauls. It can include replacing several parts or systems within the transmission rather than installing a brand new one.
What happens during a transmission rebuild?
When a mechanic rebuilds a transmission, it involves removing the transmission and completely disassembling it. Each piece is inspected for damage or wear, and a decision is made on whether to keep it or replace it. If it’s kept, it’s cleaned and used as the system is being rebuilt. Clutches, seals, gaskets, and any other easily worn items will be evaluated during this process as well.
Why are transmission rebuilds popular? Because a rebuilt transmission can be considerably less expensive than replacing the entire system. Even a rebuilt transmission can cost several thousand dollars, depending on the problems. It’s a way to keep the costs as low as possible while bringing your vehicle back to drivable condition.
There is a break-even point where a transmission rebuilt and installing a new transmission meet. As parts and labor creep upward, there’s a point where it makes more sense just to replace it. A reputable mechanic can help determine that and make suggestions along the way.
Research shows that transmissions tend to fail between 80,000 and 150,000 miles. As you approach that mileage, you can start asking yourself questions.
- How often do I bring the vehicle in for routine maintenance?
- What problems have I had in the past?
- How long do I plan on keeping this vehicle?
These questions can help you decide the best course of action. If your transmission has a history of problems, needing repair work frequently since you purchased it, it may point in the direction of replacement. If it’s never given you any problems before, rebuilding the transmission may be the solution.
Some common indicators of needing a transmission rebuild
Problems with your vehicle rarely occur instantaneously. Instead, you’ll start noticing problems build over time.
Transmission slipping – you’ll notice regular and sudden changes with gears shifting when it’s not expected. It might make a humming noise. It often happens with low transmission fluid levels, or lack of maintenance. The worse it gets, the more the gears are damaged. Too much damage would require a new transmission.
Gear shifting problems – your car won’t go without the ability to shift gears. When this starts to fail, you’ll notice it in several ways:
- A jerking sensation as it moves between gears
- Shifting without reason
- Falling out of gear while driving
- Hesitation before engaging
Burning smell – any burning smell should be checked out right away. It’s a sign of a component failing. The sooner you find the problem and fix it, the less at risk you are of the entire system collapsing.
Fluid leak – transmission fluid is a red color. If you notice it darkening, or leaking anywhere from the system, you’ll have cooling issues. Continuous leaks can result in low levels of transmission fluid, which means it’s not running through the system at optimal levels. It can damage a series of components.
Do you have transmission problems?
Whether a transmission rebuild is in your future, or a full replacement is necessary, it starts with a full inspection. Bring your vehicle in today, and we’ll help you make an informed decision.