Transmission Mount (Functions, Symptoms & Replacement)

We should never underestimate the unique qualities of cars as drivers. Just thinking about the different systems within the vehicle that work in harmony to provide mobility and comfort will leave you in awe.

This seems even more puzzling when considering how the car handles the vibration as it moves all its parts.

Usually, when thousands of metallic parts move simultaneously, we should feel their vibrations, but the car’s transmission system helps reduce these vibrations.

However, the transmission system will not work correctly without the transmission mount bracket.

This mount holds the transmission system to work effectively and provides the car user excellent comfort.

This article will discuss everything you need to know about the transmission mount, How it works, the symptoms of a bad transmission mount, How to replace it, and so much more.

Let’s get started!

The transmission mount is designed to isolate and control all vibrations from the vehicle’s driveline and ensure that the driveshaft and other linkages are in the correct position.

A transmission mount usually has a rubber or urethane bushing bonded, bolted, or welded to a mounting bracket. Depending on the brand of the vehicle, there might be one, two, or more transmission mounts.

How do Transmission Mounts Work?

The transmission mount has two major parts – the bracket and the drivetrain mount. The bracket is often made out of a strong metal, preferably steel.

On the other hand, the mount has bushing made of rubber or urethane bonded to the transmission bracket by adhesives, welds, or bolts.

The bracket secures the transmission system to the vehicle’s chassis while the bushing isolates all drivetrain vibrations and dampens the noise levels in the vehicle’s cabin.

Related: How Long Does Transmission Last?

Why Does a Transmission Mount Fail?

Mechanical parts will inevitably fail over time, and the transmission mount is no exception after 60,000-100,000 miles or more, which usually occurs from vibration and oxidation.

Oxidation chemically destroys the dampening ability of the rubber or urethane, while the vibration causes the steel bracket to fail due to cyclic stress.

In addition, lifting the engine and transmission assembly wrongly can lead to broken transmission mounts and damages from accidents (Front-end damage).

Symptoms of Bad Transmission Mount

Symptoms of Bad Transmission Mount

Different transmission mounts come in various shapes and designs, but none is immune to failure.

The engine produces such loud vibrations that you will know right away if there is a problem with the transmission mount.

However, here are five common symptoms of a bad transmission mount;

 1. Excessive Vibrations

If the vibrations from the engine start shaking the car vigorously, then that is a problem.

It is advisable to correct this problem before it becomes very intense and negatively affects other vehicle systems. This symptom will cause gross discomfort to passengers and distract the driver.

2. Difficulty Turning

This symptom will be more noticed at sharp turns on the road; if the engine is loose, it will sway whenever the car move around curves on the street, i.e., whenever you turn right, the engine will swing left, and this will result in an imbalance in the weight of the vehicle.

The sideways drag will make it harder to recover from the bend. You will even be able to feel the effects of this drug from your driver’s seat. You’ll hear strange metallic noises coming from under your hood.

This symptom is profoundly noticed around sharp bends or accelerating down but bends. You can also feel it when driving up or down a hill, although it is just one big shift in the engine’s position.

 3. Clunking, Bashing, and Banging Noise

When it seems like your engine is pulled out due to disturbing noises, it is most likely that the transmission mount is loose. The noise you hear is caused by metal bashing into metal.

Once the mounts can no longer hold the transmission system firmly to the vehicle’s chassis, the transmission will constantly and rapidly change position as the engine moves.

However, your transmission shaft will most likely not fall out of the car, but it is advisable not to drive the vehicle in that condition.

Transmissions are usually heavy and, if they are loosely fitted, can cause a lot of damage and noise by swaying and banging on other vehicle components.

If you disassemble the rear transmission mount, you won’t hear as much noise from the engine but expect noticeable noise.

4. Chassis Flex

The transmission is secured onto the vehicle’s chassis, which means if the transmission has a problem, it will also affect the chassis.

Chassis flex is a symptom that takes time to develop because it is caused by repeated shifts in the weight of the transmission. Over time the car frame (chassis) will no longer be aligned and will lose shape.

The car’s doors not being able to close and open freely is a sign that the chassis is flexing.

 5. Thumping Sounds

If your transmission mount is bad, you will hear a thumping sound whenever you drive over a bump or into a pothole.

The major cause of this sound is the motion of the transmission shifting while driving. Rather than a side-to-side movement, the thumping sound is produced by an up-and-down movement.

If you start noticing this symptom, know that the mount is very loose and could cause an accident at any time. Taking a sharp bend while driving with a damaged transmission could be very dangerous.

Replacing transmission mount parts is expensive, although the cost is greatly dependent on the model of the car.

The difficulty in accessing the transmission mount is different for different models. Still, you will need to disassemble many components to get to the failed transmission mount, which is time-consuming.

It would be best to replace all the mounts at the same time, considering the amount of work that has to be done in uncoupling and recoupling the vehicle.

Besides, all the mounts should have the same life span, and if one goes bad, it will not be long before the rest go bad.

The moment you notice that your transmission isn’t functioning correctly, you really shouldn’t drive the vehicle until you get it fixed because you can never really know the extent of its damage and how it will affect other car components.

Also Read: How Long Does it Take to Rebuild a Transmission?

How to Replace a Transmission Mount

How to Replace a Transmission Mount

A bad transmission mount has to be replaced before the car works properly. This can be done in two ways.

The first way would be to visit an auto mechanic for repairs, and the second is doing it yourself.

Because the first option is pretty expensive, you would most likely prefer the second option, which entails a DIY approach (Doing it yourself)

If you want to go with the first option, you need to search for a seasoned mechanic near you, using either a search engine on the internet or find one around your vicinity through a referral process.

Nevertheless, if you want to change motor mounts yourself, you need the right tools to change motor mounts. Some of these tools include;

  1. Wrenches
  2. Jack Stands
  3. Different sizes of extensions
  4. A hammer
  5. Some blocks of wood
  6. A pry bars
  7. A breaker bar
  8. A flat-head screwdriver
  9. A jack (preferably a bottle jack)

You can begin the repair process to replace the bad transmission mount when you have all the necessary tools in your toolbox.

Here are the steps to replace a transmission mount:

1. Locate the Bad Transmission Mount

First, secure the vehicle’s position by parking it on a flat surface and attaching the tires with wedges.

Find the mount beneath the car and then spray the bolts on the mount with penetrating fluid.

After 15 mins, the liquid must have completely seeped in; then, you can use short extensions and a breaker bar to loosen the top bolt of the mount.

Using a single wrench will not be enough, but two wrenches might do the trick.

When losing the bolts, use the second wrench to insert the open end into the closed end of the one you’re using to loosen them.

The double wrench will act as an extension that provides more torque and sufficient length.

 2. Lift Up the Vehicle

The next step is to lift the car using the jack, then set up jack stands to keep the car in place.

You have to be very careful about where you place your jack. You should place the jack in a solid part of the car suitable for carrying weight.

Next, look for a substantial part of the transmission that can jack without causing damage.

Once this point is found, place wooden blocks on the transmission and jack it up a little to remove the already loose bolts without struggle.

When you have done that, jack up the vehicle a little bit higher so that you can easily remove the transmission mount.

3. Replace the Transmission Mount

Once the damaged transmission mount is out, replace it with the new one, which must fit perfectly.

The installation of the new transmission mount will require you to be in the right position.

Once you are set, slide the new mounts into position on the vehicle. You might need a hammer and screwdriver to easily

push in the mount because it will slightly have more thickness.

When the mounts are in, jack up the vehicle a little before sliding in the bolts and fastening them. Then, lower the car and tighten all bolts equally with a torque wrench or the extended wrench you used earlier.

Check Out Video For More tips on Transmission mount replacement

Frequently Asked Question About Transmission Mount

What Happens if You Don’t Replace the Transmission Mount?

You can cause severe damage to your vehicle’s chassis if you do not replace your damaged transmission mount. Every time the transmission slams into the frame, it distributes that force through the frame and disfigures the chassis.

How Much Does It Cost to Replace a Transmission Mount?

Transmission mount replacement costs between $250 to $600. parts costs between the range of $50 to $150, and the labor cost will be between $200 to $450 due to how difficult it is to access the transmission mount.

Can You Drive With a Bad Transmission Mount?

It is not advisable to drive with a bad transmission mount. Driving with a bad transmission will cause excessive engine vibration that can cause severe damage to the vehicle.

What Can a Bad Transmission Mount Do?

Your vehicle will shake and rattle severely while accelerating whenever your transmission is bad, and in severe cases, the transmission breaks off completely, producing knocking or clunking noises.

Where Are the Transmission Mounts Located?

The transmission location varies depending on the model of the car, but usually, there are two motor mounts found each on each side of the engine that acts as supports and a single mount under the rear of the transmission.

How Long Does It Take to Change Transmission Mounts?

It takes between 48 mins and 60 mins labor time to replace each motor mount.

What Is the Difference Between the Engine Mount and Transmission Mount?

Both mounts are made of rubber and steel. However, engine mounts are designed to absorb the impact of the vibration that a rotating assembly inside an engine will generate; therefore, they secure the engine to the vehicle’s chassis. Transmission mounts perform the same function but are placed behind the engine mounts; they even attach the transmission to the vehicle’s frame.

How Long Does a Transmission Mount Last?

Transmission lasts between 5-7 years. Nevertheless, you should check it periodically since a bad road can shorten its lifespan.

How Many Transmission Mounts Are in a Car?

Vehicles typically have between three and four transmission mounts. Some motor mounts are dual purpose as they support both the weight of your transmission and car engine.

What Is the Purpose of the Transmission Mount?

The transmission mounts hold and support the engine and transmission and isolate the vibrations when the engine is running. The mounts act as a vibration insulator.

Conclusion

The ability to recognize the symptoms of a bad transmission mount is critical since your vehicle’s transmission is both costly and vital to the driving experience.

The transmission mount prevents vibrations and torque generated by the engine. Once the transmission fails, the vehicle performs poorly, and over time the engine will suffer severe damages.

Identifying these symptoms on time will save you a lot of repair costs.

Scott Greene is a seasoned automotive technician for over 5 years and has been deep into advanced automotive diagnostics for a couple of years. He Loves writing about Automotive Diagnostics and Repair, Trouble codes, Buyer guides for various car parts and accessories, and lots more. 

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