Motor mounts secure the engine to the vehicle’s frame. While a transmission mount secures the transmission to the vehicle’s frame. Motor mounts dampen the engine vibrations and transmission mounts dampen transmission vibrations. Typically, motor mounts are cheaper than transmission mounts.
But, there’s much more to know here. Thus, this article has elaborated on the topic as much as possible. Be sure to read all of it.
Motor Mount Vs Transmission Mount – Quick Overview
There are quite some dissimilarities between the motor mount and the transmission mount. First, let’s look at a brief table about these differences below:
|To connect the car engine to the frame and stabilize engine vibration
|To absorb and transfer transmission-related vibration
|1. Between the engine and the frame
2. For Front Wheel Drive: Perpendicular to the vehicle’s centerline
3. For Rear Wheel Drive: Sides of the engine
|1. Perpendicular to the vehicle’s centerline
2. On the sides of the engine
|Rubber and metal
|Urethane or rubber
|Symptoms of Failure
|1. Excessive lurch while starting
2. Noise coming from engine bay
2. Visual signs of wear
|1. Excessive vibration while driving
2. Noise when shifting gears
3. Misaligned chassis
|Consequences of Failure
|1. Engine will be damaged
2. Fan belts and radiator hoses will be damaged
3. Cause safety hazard
|1. Difficulty in controlling car
2. No power to wheels
3. Transmission will slip
But, these factors need much more explaining.
Motor Mount Vs Transmission Mount – Detailed Overview
Although both motor and transmission mounts reduce vibrations, undoubtedly they’re different. The key points have been discussed in the table. Now, let’s elaborate on them.
The main function of a motor mount is to connect the engine to the car’s frame. The engine is continuously subjected to internal and external vibrations. The motor mount isolates these shocks to prevent engine and related components from damage.
Transmission mounts also minimize these vibrations and control the torque-related vibration and shock alongside the motor mount. Thus, the transmission can operate smoothly. Here, you should also know about the best transmission.
The transmission mount also protects the proper position of the linkages in your vehicle.
Linkages connect the transmission to other parts of the drivetrain like the driveshaft and the engine.
It supports your transmission assembly. It also supports the right angling of your driveshaft boots. Thus, the joint of the axle is protected from contamination and water.
Motor mounts are placed between the engine and the vehicle’s frame. Thus, when your car vibrates, the mount can absorb it and protect the engine. In some cars you will find three to four motor mounts, the location is accurately given in the user manual.
On the other hand, the transmission mount is located in different places for different vehicles. You’ll find it between the frame and the transmission.
In SUVs, front-wheel-drive cars, and minivans, it’s located perpendicular to the vehicle’s centerline. For trucks and rear-wheel-drive cars, it’s on the sides of the engine.
Motor mounts are made using rubber and metal. The metal is bolted to the engine and the car’s frame on separate sides. On the other hand, the rubber in between provides flexibility. Thus, the car doesn’t shake from the engine’s vibration. The mount clamps everything smoothly and offers better acceleration by lessening vibration.
But, there are also some other types of motor mounts. They use liquid oil instead of rubber to dampen the vibration. They’re also solid steel and polyurethane mounts that transfer the vibration.
A transmission mount is mainly made of the mount itself and a bracket. The bracket is usually made of steel. And, the mount is made using rubber or urethane bushing. It’s chemically bonded, welded, and bolted to the bracket.
Normally, the rubber or urethane isolates the vibration and lessens noise quite well. But, if one component is damaged the whole unit has to be replaced.
Symptoms of Failure
If a motor mount or transmission mount is bad, it’ll show certain symptoms. So, what are the symptoms of a bad motor mount?
When you start the vehicle, you’ll notice an excessive lurch. This lurch will steadily turn into a continuous vibration. You’ll hear clunking sounds or bangs coming from the engine bay. This happens because the engine will move around more.
If you inspect the mount, you’ll see flaking or cracks in the rubber of the mount. You might also have corrosion on the metallic part. Thus, the mount won’t be able to perform properly.
And, what are the symptoms of a bad transmission mount?
If it’s bad, you’ll feel excessive vibration from the steering wheel, seat, or floorboard. It happens because the transmission isn’t isolated from the car properly. You’ll hear clanking noises while shifting gears and thumping sounds while crossing a bump.
Since the transmission mount is bad, it won’t be able to hold the transmission in place. It’ll cause the chassis to tilt to one side. This will cause steering problems and uneven wear on tires. The car will try to pull on one side.
Summary:A bad motor mount will make clunking sounds from the engine bay. You’ll see cracks and corrosion on the mount. On the other hand, bad transmission mounts will make sounds while shifting gears. You’ll have lesser control over the car.
Consequences of Failure
If the motor or transmission mount fails to serve its purpose, the consequences will be terrible. So, what happens if the motor mount is bad?
As the engine mount is bad, it’s unable to hold the engine in place. Thus, the engine might move a bit from its original position. Thus, it might end up damaging other compartments like the hose, bearings, and wirings.
Since the vibrations are no longer absorbed properly, it’ll also create pressure on other components. The fan belts and radiator hoses will be subjected to these high vibrations. Thus they might snap or stretch.
Thus, all of these damaged components will create a safety hazard. It’s very dangerous to drive your vehicle with a bad motor mount.
And, what happens if the transmission mount is bad?
If the mount is bad, it can allow excessive transmission vibration, which can be felt throughout the vehicle. This can make the vehicle feel rough or shaky, and it can cause additional wear and tear on other components in the drivetrain system.
A damaged transmission mount might also lead to a broken driveshaft. So, the power won’t be transferred from the engine to the wheels. Thus, your car will become unable to move. It’s one of the reasons why your transmission goes bad.
The transmission might also slip if you have a damaged transmission mount. It’ll cause the transmission fluid to leak. As a result, the transmission will slip due to lower fluid levels. So, you shouldn’t drive with a broken transmission mount.
Summary:If the motor mount is bad, the engine components like the fan belt and radiator will be damaged. It will also make your vehicle difficult to control. The car might not even move and the transmission might slip.
Like any other components, the motor and transmission mount also wears out over time. So, how long do motor mounts last?
Generally, a motor mount should last about 5-7 years. Still, you should check them regularly while servicing your car. Depending on the use, they might last less or longer.
And, how long do transmission mounts last? They should last for about 60000-100000 miles. Depending on the oxidation and vibration, it might last more or less.
If the mounts are bad, obviously they have to be replaced. So, how much does it cost to replace the motor mount?
Replacing steel or rubber mounts might cost about $10-$150. This depends on the model of the vehicle. For example, complicated hydraulic and active motor mounts are more expensive. You might expect a range of $50-$200 for these mounts.
Here, the labor charge will depend on how tough it is to access the mount. Generally, it might be approximately $150-$450.
And, how much does it cost to replace the transmission mount?
Generally, it might cost about $264-$292 to replace transmission mounts. Here, the parts cost about $160 and the rest is the labor charge. This fee doesn’t include tax and other fees. You can save this expense if you replace the mount yourself.
Should I Replace All Engine Mounts at Once?
No, if all of the engine mounts aren’t damaged, you don’t need to replace them at once. Generally, there are three or four motor and transmission mounts in your vehicle. It’s unusual that all of them will go bad at once. In that case, just replace the engine mount that has been damaged.
Can I Replace Motor Mounts Myself?
Yes, you can replace your motor mounts with the right tools. Use a piece of wood on top of a jack to lift up the engine. This will remove weight from the mount. Then, remove any bolts and brackets holding the mount. Use a pry bar to remove the mount. Finally, take the new mount and attach it.
How Can I Tighten The Engine Mounts?
To tighten the engine mounts, you’ll have to use a torque wrench. After load equalization and alignment, use two wrenches or spanners for the final adjustments. Hold the adjusting nut with one and tighten the lock nut with the other one. Thus, the nuts will be properly tensioned.
Hopefully, now you know what is the difference between a motor mount and a transmission mount? Still, we’d like to mention one last thing. Power breaking before takeoff can cause the motor mounts to break. Hope you enjoyed reading our article.