Having your car vibrate when in drive but run smooth in neutral can be frustrating and a bit alarming. However, the issue is usually easy to diagnose and repair with some basic troubleshooting.

Common Causes of Vibrations in Drive But Not Neutral:

• Engine mounts
• Transmission mounts
• U-joints
• CV joints
• Driveshaft
• Tires and wheels
• Misalignment
• Worn components

Diagnosing the cause involves methodically checking different systems and components. Here is a step-by-step approach:

1. Test in Neutral at Different Speeds

Start by verifying the vibration happens only in drive.

• Shift to neutral and increase engine RPMs. Is there still a vibration?
• Get the car to 30-40 mph in neutral. Any vibrations?

If you feel vibrations in neutral at various speeds, it likely points to an engine or drivetrain issue.

2. Test in Park with Brake On

Now try this:

• Put the car in park with the parking brake engaged.
• Rev the engine to 2500-3000 rpm.

Do you notice the vibration? If so, it indicates a problem with the engine mounts, engine, or transmission mounts.

3. Jack up the Car and Check Components

Jacking up the car and checking underneath can reveal issues.

• Safely jack up the car and support it on jack stands.
• Check the transmission mounts, engine mounts, U-joints, and CV joints for deterioration or slack.
• Spin the wheels and check for play in the wheel bearings.
• Are the driveshafts damaged or loose?

Worn engine or transmission mounts or damaged U-joints or CV joints can cause drive vibrations.

4. Test Drive and Feel Vibration Points

Go for a test drive and change speeds to isolate the vibration:

• Accelerate from 0 to around 30 mph. When does the vibration occur?
• Let off the gas and coast down to 10 mph. Vibration?
• Brake smoothly to a stop. Vibration when braking?

See if you can narrow down when and where the vibration happens. Up front? Rear? At certain speeds? This can further pinpoint causes.

5. Check Wheels, Tires, and Alignment

Don’t forget the wheels and tires:

• Inspect tires for abnormal wear or damage.
• Check wheel bearings for play by rocking tire/wheel.
• Verify lug nuts are tight.
• Alignment may be off causing vibration when accelerating.

Tire balance issues or misalignment are common sources of drive vibrations.

6. Look for Looseness

Finally, do a visual inspection under the car for any looseness:

• Transmission mount bolts tight?
• Check engine mount bolts.
• Any visible damage or play in U-joints or CV joints?
• Driveshafts secure?

Loose components can vibrate when torque is applied through the drivetrain.

Top Causes of Vibration in Drive But Not Neutral

Now that you know how to diagnose the issue, here are the most common culprits:

1. Worn Engine Mounts

Over time, rubber engine mounts deteriorate and allow excessive engine movement. This lets the engine rock back and forth when accelerating and braking.

Bad mounts are most noticeable at idle in drive when holding the brake pedal.

Fix: Replace worn, cracked, or damaged engine mounts.

2. Worn Transmission Mounts

Like engine mounts, transmission mounts can wear out or break. This allows drivetrain movement under torque resulting in vibrations.

Fix: Inspect and replace damaged transmission mounts.

3. Damaged U-Joints

U-joints connect the driveline to the transmission and differential. If they get damaged or loose, it can make the drivetrain vibrate when applying gas in drive.

Fix: Tighten/replace damaged U-joints.

4. Bad CV Joints

CV joints transfer power to the wheels at the ends of the axles. Worn out or damaged CV joints can cause shuddering when accelerating from a stop.

Fix: Inspect CV joints and replace if necessary.

5. Out of Balance Wheels

Wheels that are out of balance can cause vibrations, usually at higher speeds. Out of balance tires will typically vibrate in both drive and neutral.

Fix: Remove, inspect, and rebalance the wheels/tires.

Common Reasons for Vibration in Drive But Not Neutral

Here are some of the most common culprits for drive vibrations:

• Worn engine mounts – Allow excessive engine movement under torque.
• Bad transmission mounts – Permit drivetrain to shake under acceleration/braking.
• Damaged U-joints – Can cause driveline vibrations when applying gas.
• Bad CV joints – Cause shudder/vibration when accelerating from stop.
• Misaligned wheels – Lead to vibration at high speeds.
• Bent wheel – Will vibrate due to imbalance.
• Out of balance tires – Usually vibrate at high speeds.
• Loose lug nuts – Allow wheels to wobble.
• Worn driveshaft – May vibrate when spinning.
• Bad wheel bearings – Can cause wheel shudder when accelerating.

If you methodically check each component, you should be able to isolate the cause of the vibration.

Fixing Drive Vibration Issues

Here are some tips on repairing common causes of drive vibrations:

• For engine mounts – Replace damaged or worn mounts to stop engine shaking. Use mount lock nuts to secure.
• For transmission mounts – Inspect condition and tighten or replace as needed.
• For U-joints – Confirm no slippage or play. Tighten or replace any damaged joints.
• For CV joints – Listen for clicking on turns. Replace any damaged joints.
• For wheels/tires – Inspect for damage or imbalance. Rebalance or replace as needed.
• For driveshaft – Check for damage or runout. Replace if necessary.
• For wheel bearings – Listen for noise when spinning wheel. Replace bearings if worn.
• For loose parts – Check all components are tight and secure.

Finally, get an alignment to address any underling misalignment issues. This will help prevent premature tire wear as well.

Diagnosing Car Vibration: Step-By-Step

Feel a vibration in drive but runs smooth in neutral? Follow this process to diagnose the issue:

1. Test in neutral – Increase RPMs and get to higher speeds. Vibration?
2. Test in park – Rev engine while holding brake. Vibration points to mounts or engine.
3. Inspect under car – Check mounts, U-joints, CV joints for problems.
4. Test drive – Accelerate and brake smoothly. When does vibration happen?
5. Check tires/wheels – Any damage or imbalance? Lug nuts tight?
6. Inspect under car again – Look for any loose or damaged components.
7. Consider alignment – May help with vibrations at higher speeds.

Following these steps can quickly lead you to the root cause, whether it be worn mounts, damaged joints, or wheel imbalance.

Maintenance to Prevent Drive Vibrations

Here are some car maintenance tips to help avoid drive vibrations in the first place:

• Inspect engine mounts – Check for cracks or deterioration every 60k miles.
• Check transmission mounts – Look for damage/wear each transmission service.
• Lubricate driveshaft – Grease slip joints yearly to prevent wear.
• Inspect axles and CV joints – Check boots for cracks/damage yearly.
• Check wheel bearings – Listen for noise when spinning wheels every brake service.
• Tire balancing – Rebalance tires with each tire rotation or anytime vibration develops.
• Wheel alignment – Align wheels with each new set of tires or any vibration issues.
• Check torque on lug nuts – Ensure lug nuts are tight to spec with each tire change or rotation.

Following basic maintenance intervals and checks can help reduce the likelihood of drive vibration issues occurring.

FAQ about Drive Vibrations

Q: What are the most common causes of vibration in drive but not neutral?

A: The most common culprits are worn engine mounts, bad transmission mounts, damaged U-joints or CV joints, wheel imbalance, and driveline misalignment.

Q: What should I check first if my car vibrates in drive?

A: Start by testing in neutral at various speeds. Then test in park while revving the engine. This can help narrow down the cause.

Q: How can I tell if my engine mounts are worn out?

A: With the car in park and brakes on, rev the engine to 2500 rpm. If you feel excessive vibration, the engine mounts may be worn. Visual inspection will confirm.

Q: Should I be concerned if I feel vibration when accelerating?

A: Some vibration when accelerating is normal, but excessive shaking or vibration should be inspected. Acceleration vibrations typically point to drivetrain issues.

Q: Can worn tires or wheels cause a vibration in drive?

A: Yes, imbalance in the tires/wheels is a common source of drive vibrations, especially at higher speeds. Inspect tires carefully.

Key Takeaways on Drive Vibrations

• Vibrations primarily in drive can point to engine mounts, transmission mounts, U-joints, or other drivetrain issues.
• Methodically test and inspect components to isolate the cause.
• Damaged or loose drivetrain parts should be repaired as soon as possible.
• Check for tire balance, wheel damage, loose lugs, and misalignment.
• Follow maintenance intervals for critical components like mounts, axles, and wheel bearings.
• Addressing vibrations promptly can prevent further component wear.