1. Engine Mounts Deals
  2. sku: 21627627686660892
  3. LEXUS 12371-50010

LEXUS 12371-50010 Insulator Engine Mounting Rear NO.1

fits model: Ls400. make: Lexus. year: 1990–1994.

12371-50010 Lexus Genuine 1990-1994 Ls400 Insulator Engine Mounting Rear No.1

( Manufacturer Part Number: 12371-50010 ), ( Items Included: Rear Mount ), ( Type: Engine Mount ), ( Country Of Origin: Japan )

Review LEXUS Genuine Insulator Engine Mounting Rear No.1 fits LS400 1990–1994

The **Lexus 12371-50010 Insulator Engine Mounting (Rear No. 1)** is a critical, high-performance component designed specifically for the **1990 1994 Lexus LS400** (and its Toyota counterpart, the **Toyota Crown Royal**) to ensure optimal engine stability, vibration suppression, and long-term durability. This part belongs to the vehicle s **engine suspension system**, playing a pivotal role in isolating engine vibrations from the chassis while maintaining precise alignment and reducing noise, harshness, and excessive wear on surrounding components. Crafted from high-grade **rubber and reinforced polymer materials**, the insulator is engineered to withstand the LS400 s powerful **3.0-liter V8 engine**, which produces up to **220 horsepower** in its base form, delivering a balance of comfort and performance. The mounting is strategically positioned at the **rear of the engine bay**, anchoring the powerplant to the subframe while allowing for slight movement to absorb dynamic forces during acceleration, braking, and rough road conditions. Over time, exposure to heat, road debris, and mechanical stress can cause the insulator to degrade, leading to rattles, misalignment, or even catastrophic engine detachment a risk that this **OEM-quality replacement** effectively mitigates. Whether installed during routine maintenance or as part of a **restoration project**, this part ensures that the LS400 s legendary driving dynamics remain intact, preserving the vehicle s legendary blend of luxury and mechanical precision. Proper installation requires careful attention to torque specifications and alignment, as even slight misalignment can compromise ride quality or engine performance. For enthusiasts and mechanics alike, this component is an essential upgrade for maintaining the LS400 s legendary reliability and driving enjoyment.

### **Analysis of buying a Lexus LS400 (1990-1994) Rear Engine Mounting Insulator (Part #12371-50010)**

#### **Pros of Purchasing This Part**

1. **Prevents Engine Noise and Vibration** The insulator acts as a vibration dampener, reducing road noise and harshness transmitted to the cabin. Over time, these mounts degrade, leading to increased rattling and discomfort, so replacing them improves ride quality.

2. **Extends Engine Mount Lifespan** Worn mounts can cause excessive stress on the engine block and suspension components. A fresh insulator helps distribute forces more evenly, potentially preventing costly damage to the engine or subframe.

3. **Improves Driving Comfort** A properly functioning mount system ensures smoother power delivery and reduces fatigue during long drives, which is particularly noticeable in larger luxury vehicles like the LS400.

4. **Prevents Further Damage** If the mount is already cracked or failing, delaying replacement could lead to more severe issues, such as subframe cracks or engine misalignment, which are expensive to repair.

5. **OEM Quality (If Purchased New)** Lexus parts are generally reliable, and using an original or high-quality aftermarket replacement ensures compatibility and durability.

6. **Easy Installation** This part is relatively straightforward to replace, requiring basic tools and mechanical knowledge. Many owners or even inexperienced DIYers can complete the job in a few hours with proper guidance.

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#### **Cons of Purchasing This Part**

1. **Cost** OEM Lexus parts can be expensive, often ranging between **$150 $300** depending on the source (new vs. used/rebuilt). Aftermarket alternatives may be cheaper but could vary in quality.

2. **Potential Counterfeit Parts** Buying from untrusted sellers (especially online marketplaces) risks receiving low-quality or fake parts. Always verify the seller s reputation and part authenticity.

3. **Labor Time** While not overly complex, replacing engine mounts requires lifting the vehicle and accessing the subframe, which may take **1 3 hours** depending on experience. Some owners may prefer professional installation ( $150 $300 in labor).

4. **Secondary Issues May Arise** If the mounts have been damaged for some time, other components (e.g., subframe bolts, engine mounts, or suspension parts) may also be worn and could require replacement simultaneously.

5. **Limited Lifespan of Aftermarket Parts** Cheaper aftermarket insulators may wear out faster than OEM parts, potentially requiring replacement sooner than expected.

6. **Diagnostic Uncertainty** If the noise/vibration is caused by something other than the insulator (e.g., a cracked subframe, loose engine mounts, or exhaust issues), replacing just this part may not fully resolve the problem.

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#### **Conclusion**

The **Lexus LS400 rear engine mounting insulator (12371-50010)** is a **practical and cost-effective preventive maintenance item** for owners experiencing vibration or noise issues. Replacing it is a **proactive measure** that enhances comfort, prevents further damage, and avoids more expensive repairs down the line.

However, the decision should be based on:

- **Symptoms**: If the noise/vibration is confirmed to be coming from the rear insulator (not the engine mounts or subframe), replacement is justified.

- **Budget**: Weigh the cost against potential future damage. If the part is failing, the expense is a small price for long-term reliability.

- **Source**: Purchase from a **reputable dealer or trusted aftermarket supplier** to avoid counterfeit or low-quality parts.

- **Additional Checks**: If the subframe or other mounts appear worn, consider replacing them simultaneously to avoid recurring issues.

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#### **Recommendation**

1. **If the insulator is visibly cracked or causing noticeable noise/vibration**, **replace it as soon as possible**. The cost is justified to prevent further damage.

2. **If unsure about the source of the noise**, have a mechanic inspect the **engine mounts, subframe, and exhaust** before purchasing this part.

3. **Opt for OEM or a high-quality aftermarket brand** (e.g., Denso, ACDelco, or Mann) to ensure longevity.

4. **Consider professional installation** if you lack confidence in DIY mechanics, especially if other components (like subframe bolts) need attention.

5. **Budget for potential secondary parts** if the subframe or other mounts are degraded, address them during the same service to avoid repeated trips.

**Final Verdict**: **Worth purchasing and replacing** if the symptoms align with a failing insulator, as it is a **low-risk, high-reward** maintenance item for the LS400. Prioritize quality and proper installation to maximize benefits.

Details:

Only con is that the paint peeling around rubber areas, but they still feel solid. New condition.

part #: 1237150010 prices

  • $52.46-$57.22

specifications engimou:

  • for models: Ls400
  • for makes: Lexus
  • for years: 1990-1994
  • mpn: 12371-50010
  • items included: Rear Mount
  • type: Engine Mount
  • country of origin: Japan

returns engimou:

  • policy: No Returns

offer engimou:

  • quantity: 1
  • best offers: True
  • options: Ship-to-home
  • started: February 25, 2026
  • availability: In Stock
  • sold: 0

shipping engimou:

  • transit: 3-8 Days
  • carrier: USPS
  • class: Standard
  • cost: $15.25
  • type: Calculated
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  • condition: New other see details
  • Car Truck Parts Accessories > Engines Engine Parts > Engine Mounts

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  • # reviews: 525
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for models: ls400, for makes: lexus, for years: 1990-1994, items included: rear mount, type: engine mount, country of origin: japan,
category: auto parts > car truck parts accessories > engines engine parts > engine mounts, sku: 21627627686660892,
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