How to replace a broken exhaust mount
Exhaust mounts keep your vehicle's exhaust system safe and reliable. Symptoms of a malfunction include rumbling, knocking, and thumping from under the vehicle.
Your car's exhaust system is a collection of pipes, mufflers, and emission control devices that are connected end-to-end. Combined, it's almost as long as your car and can weigh up to 75 pounds or more. The exhaust system is attached to the engine at one end and hangs from the car body for the remainder of its length. The exhaust system must be able to absorb all the noise and vibrations from the engine without transmitting them to the car body and passengers.
A series of flexible suspensions hold the exhaust in place, allowing it to move with the engine. Most cars have a rigid support bracket, usually at the rear of the transmission, that securely attaches the engine and transmission to the exhaust pipe so that the front of the pipe can move with the engine as it vibrates and twists with the torque reaction. If this support breaks, other parts of the exhaust system, such as the flex pipe or exhaust manifold, can stress crack and fail shortly thereafter.
The first signs of a problem with this support may be a rattling or thumping sound from under the car, sometimes associated with pressing or releasing the gas pedal. You may even notice a thud and vibration when you put the car in reverse. In some cases, you may not notice any symptoms or know about the problem until a pipe or manifold ruptures unless you have your exhaust system inspected.
Part 1 of 1: Exhaust Support Bracket Replacement
Necessary materials
- combination keys
- Jack
- Jack stands
- Mechanic Creeper
- User's Guide
- Safety glasses
- Socket wrench set
- Support bracket and related fittings
- WD 40 or other penetrating oil.
Step 1: Raise the car and place it on jacks.. Look in your owner's manual for recommended jacking points on your vehicle. These points will be slightly reinforced to withstand the load of the jack.
Jack up the car and leave it on the jacks.
- Attention: Working under a car can be very dangerous! Be especially careful to make sure the vehicle is securely fastened and cannot fall off the jack.
Once you have the car on stands, pull the floor jack back out as you may need to place it under the exhaust pipe later.
Step 2: Spray penetrating oil on the bolts.. Exhaust system mounts are usually rusty and the job will be made easier if you pre-treat all nuts and bolts with WD 40 or other penetrating rust removing oil.
- Functions: It's best to spray the bolts with oil and then do something else for a couple of hours. When you get back to work, everything should move smoothly.
Step 3: Remove the bolts. Turn out bolts of fastening of a support to transmission and an exhaust pipe. In many cases, there are rubber damping washers under the bolts. Keep all these parts or replace them if necessary.
Step 4: Install the new support. Install a new support and reattach the exhaust pipe.
- Functions: It may be helpful to place a floor jack under the exhaust pipe and raise it so that it is in contact with the exhaust pipe before attempting to reinsert the fastener.
Step 5: Check Your Work. Grasp the exhaust pipe and give it a good shake to make sure there are no unwanted movements. Make sure the exhaust pipe does not hit other parts of the car.
If everything is in order, lower the car back to the ground and start the engine.
After a few minutes, you may see some smoke from penetrating oil onto the fasteners. Do not worry, it will stop smoking after a few minutes of operation.
Take the car for a walk and pass a few speed bumps to make sure no part of the exhaust is hitting the car.
A broken exhaust system mount adds stress to all other exhaust system mounting points. Neglecting a cracked or broken support can result in more costly damage.
If you have reason to suspect an exhaust system problem, invite a trained AvtoTachki mechanic to your home or office and inspect the exhaust system.
