Can I drive with a bad transmission mount?

A bad transmission mount is not something to drive with long-term. It can allow excessive engine and transmission movement, potentially causing additional damage and affecting vehicle control. If you suspect a bad mount, arrange a tow or professional inspection rather than continued driving.

What a transmission mount does

Core functions

The following paragraph explains the primary roles of transmission mounts and why they matter for reliability and comfort.

• Keep the transmission aligned with the engine and driveshaft to ensure smooth engagement of gears


• Absorb and dampen vibrations from the engine and drivetrain to reduce cabin noise and harshness


• Limit unwanted movement of the transmission during acceleration, braking, and cornering


• Protect connected components like exhaust, coolant lines, and wiring from engine/transmission movement


• Help maintain proper gear engagement and shift feel by preserving correct geometry

In short, transmission mounts are a critical link that stabilizes the drivetrain, minimizes vibration, and protects surrounding components.

Common signs of a bad mount

Visual and audible clues

The following indicators can suggest a failing transmission mount. If several appear together, a professional review is warranted.

• Clunking, banging, or thudding noises when going over bumps or during shifts


• Excessive engine or transmission movement noticeable at idle or under load


• Vibration or harsh ride transmitted through the floor, pedals, or steering wheel


• Drivetrain misalignment that may cause parts like the driveshaft or exhaust to contact other components


• Visible cracking, tearing, or oil contamination of rubber mounts

If you observe these symptoms, avoid hard driving and schedule a diagnostic to prevent further damage.

Why driving with a bad mount is risky

Continuing to drive with a deteriorated or broken transmission mount can lead to escalating problems beyond the mount itself. Here are the key risks to consider.

• Progressive wear or damage to the transmission, engine, or related mounts due to uncontrolled movement


• Potential damage to driveshaft, CV joints, exhaust system, or coolant/oil lines from abnormal movement


• Increased vibration and reduced ride quality, which can mask other mechanical issues


• Possible safety concerns if excessive engine movement affects throttle response or shifter linkage in certain designs

These factors can raise repair costs and downtime, so timely diagnosis and replacement are advisable.

Diagnosis and repair options

How professionals assess and fix the issue

Mechanics diagnose a bad transmission mount through a combination of visual inspection, movement testing, and road testing. The process typically includes examining perches, mounts for cracks or oil contamination, and measuring engine/transmission movement under load.

• Visual inspection of each mount and mounting points for cracking, separation, or oil contamination


• Functional check by observing or measuring engine movement during startup, idle, and light load


• Tightening or replacing worn or damaged mounts, often replacing the relevant set of mounts rather than a single unit


• Assessing related components that may have been affected or may require realignment after mount replacement

Repair generally involves replacing the worn mount(s) with OEM or aftermarket equivalents designed for your vehicle. Some cars use hydraulic mounts or performance variants, which can affect both cost and installation complexity. If other drivetrain components show wear, those may be addressed at the same time to avoid repeated labor costs.

Costs and timing

Prices vary by vehicle, mount type, and labor rates. The following ranges offer a general idea, but actual quotes will depend on your make and model.

• Parts: rubber mounts typically range from about $40 to $150 per mount; hydraulic or specialized mounts can be higher


• Labor: roughly $150 to $350 per mount, depending on access and shop rates


• Total: replacing one mount may run a few hundred dollars, while replacing multiple mounts can approach or exceed the low thousands for some vehicles

Always obtain a written estimate that itemizes parts and labor, and consider replacing related mounts if multiple are worn to avoid repeat labor charges.

Short-term driving guidance

When you must move the vehicle

If you absolutely need to move the car before repair, limit vibrations and avoid high speeds. Drive slowly, avoid aggressive acceleration or hard braking, and plan a route to a repair shop or tow service rather than a long trip. If the mounting is severely compromised, towing is the safer option.

Summary

Bottom line: A bad transmission mount should not be treated as a minor issue. It can lead to greater drivetrain damage and safety concerns, and it typically worsens if driven aggressively. Have the car inspected by a qualified technician, obtain a clear repair plan and estimate, and replace the faulty mount(s) to restore alignment, reduce noise and vibration, and protect other components. Addressing the problem promptly minimizes the risk of cascading failures and additional costs.

Conclusion

For most drivers, continuing to drive with a known bad transmission mount is not advisable. Prompt diagnosis and replacement by a qualified mechanic helps preserve drivetrain integrity, maintain safe handling, and prevent more extensive repairs down the line. If you’re unsure about the severity, seek a professional opinion as soon as possible.

Summary of key takeaways

A bad transmission mount can cause excessive movement, noise, and vibration; it risks damage to the drivetrain and surrounding components; diagnosis involves visual inspection and movement testing; repair usually means replacing the mount(s) with proper parts, and costs vary widely by vehicle and complexity. When in doubt, err on the side of caution and pursue a professional assessment promptly.

Can transmission mounts cause jerking?

Yes, a bad transmission mount can cause a car to jerk, especially during acceleration or when shifting gears. A failing mount can no longer hold the transmission securely, leading to abrupt movements that feel like jerking or clunking. It can also cause vibrations, and some other issues like a stuck governor or low transmission fluid can have a similar effect. 
This video explains the symptoms of a bad transmission mount: 53sHonest Mechanic ColoradoYouTube · Mar 12, 2024
How a bad transmission mount causes jerking

• Improperly secured transmission: The mount's job is to absorb vibrations and keep the transmission in place. When the mount is worn or broken, the transmission can move excessively. 
• Jerking during shifts: This excessive movement can result in sudden, jarring shifts between gears because the transmission is not held firmly. 
• Clunking noises: The physical movement of the transmission can also cause a clunking or thumping sound, particularly when starting from a stop or when the gear is changed. 
• Vibrations: A bad mount can't dampen the engine's vibrations as it should, leading to a shaky or vibrating sensation while driving, especially under acceleration. 

What else could cause jerking

• Low or dirty transmission fluid: This can cause rough shifting and jerking, so it's important to check the fluid level and condition. 
• Worn internal components: Internal parts like clutches, solenoids, or the governor can wear out, leading to poor or delayed shifts. 
• Clogged fuel injectors: Dirty fuel injectors can cause the engine to misfire and lose power, which can feel like jerking while accelerating. 

What to do
If you experience jerking, it is best to have all engine and transmission mounts checked for any issues. A qualified mechanic can also diagnose other potential problems, such as low fluid or internal transmission issues.

How long can you drive a car with bad motor mounts?

Driving with a bad motor mount is inadvisable. It is technically possible to drive short distances, but prolonged use will inevitably destroy your motor mount beyond repair. When you replace a motor mount, be sure to replace every single motor mount.

How much does it cost to replace a transmission mount?

The average cost for a transmission mount replacement is between $200 and $800, but can vary based on your vehicle's make and model, as well as the complexity of the job. Some estimates show costs as low as $200-$600, while others suggest costs can exceed $1,000 for more difficult jobs or luxury vehicles. 
Cost breakdown and factors

• Parts: A transmission mount itself can range from about $50 to $150 or more, depending on the brand and your vehicle's make. Higher-quality or OEM (Original Equipment Manufacturer) parts are often more expensive. 
• Labor: Labor costs typically make up the bulk of the repair. The time it takes to complete the job can vary significantly. 
  • For simple mounts, the repair may take a few hours. 
  • However, if the mount is in a difficult-to-access location, it can require removing other components, which increases labor time and cost. 
• Vehicle make and model: Luxury vehicles or cars with more complex, modern mounts (like hydraulic or active mounts) will likely have higher repair costs. 
• Additional work: If other mounts (like engine mounts) are also worn, replacing them at the same time can be more efficient and cost-effective in the long run, as the labor can be combined. However, this will increase the total bill. 

Tips to manage costs

• Get multiple quotes from different shops to compare prices. 
• Ask about the difference between OEM and aftermarket parts for your vehicle. 
• Ask the mechanic to inspect your other mounts (like engine mounts) to see if they also need to be replaced. 

What happens right before your transmission goes out?

You can tell your transmission is about to go out by listening for unusual noises like grinding or whining, and by observing issues like slipping gears, delayed or harsh shifting, or hesitation when accelerating. Other signs include a burning smell, transmission fluid leaks, and the illumination of the "Check Engine" light. 
Symptoms of a failing transmission

• Unusual sounds: Listen for grinding, whining, clunking, or humming noises. A loud or rough sound when shifting gears is a major warning sign. 
• Shifting problems:
  • Slipping: Your car may feel like it's shifting gears on its own, especially when accelerating. 
  • Hesitation or delay: There may be a noticeable delay when shifting into gear or when the engine revs before a gear change. 
  • Rough or hard shifts: Shifts may feel jerky or harsh instead of smooth. 
• Fluid issues:
  • Leaking fluid: A red or brown puddle under your car could indicate a transmission fluid leak. 
  • Burning smell: A sweet, burning smell often points to overheating transmission fluid. 
• Warning lights: The "Check Engine" light or a dedicated transmission warning light can come on to indicate a problem with the transmission. 
• Performance issues:
  • The vehicle may be slow to accelerate or feel sluggish. 
  • The car may not move when you put it in gear and press the gas pedal. 

What to do
If you experience any of these symptoms, have your vehicle inspected by a professional mechanic as soon as possible. Driving with a failing transmission can lead to more severe and costly damage.