🔧 Highlander - Timing Belt Replacement

Your Highlander’s 3.5L V6 uses a timing chain, not a timing belt. That means there is no routine “timing belt replacement” service on this engine; the chain lives inside the engine and is lubricated by engine oil.

If you’re trying to fix a noise, a leak, or a warning light, the next steps depend on what you’re actually seeing/hearing.

Difficulty Level: Advanced | Estimated Time: 10-16 hours (timing chain service)

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before working near the radiator/exhaust.
• ⚠️ Support the SUV with jack stands on a level surface; never rely on a jack.
• ⚠️ Timing chain work requires supporting the engine; improper support can cause injury or damage.
• ⚠️ Disconnect the negative battery terminal before any under-hood disassembly.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" drive ratchet
• 1/2" drive breaker bar
• Torque wrench (10-200 ft-lbs range)
• Trim clip removal tool
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• Engine support bar (specialty)
• Harmonic balancer puller kit (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Timing chain kit - Qty: 1
• Timing cover sealant (Toyota FIPG equivalent RTV) - Qty: 1
• Crankshaft front oil seal - Qty: 1
• Engine oil (0W-20 full synthetic) - Qty: 7 quarts
• Oil filter - Qty: 1
• Engine coolant (Toyota Super Long Life equivalent) - Qty: 2-3 gallons
• Serpentine drive belt - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks at the rear wheels.
• Disconnect the battery using a 10mm socket and isolate the negative cable.
• If your goal is routine maintenance: stop here—there is no timing belt interval on your Highlander.
• Please answer these so I can guide you correctly (pick one): are you trying to replace the serpentine belt (the external accessory belt), or are you having a timing chain symptom (rattle, oil leak, check engine light)?

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm what you’re trying to replace

• Open the hood and look at the front of the engine with a flashlight.
• If you see a rubber belt running around pulleys (alternator/A/C), that’s the serpentine belt, not a timing belt.
• If you cannot see any “timing belt” without removing metal covers, that’s because your Highlander uses a timing chain inside the engine.

Step 2: If your issue is a front-of-engine oil leak, verify the source

• Use a 10mm socket and trim clip removal tool to remove the upper plastic engine cover (if equipped).
• Look for wet oil around the front timing cover seam and crank pulley area.
• Clean first; leaks are easier to trace.

Step 3: If your issue is a rattle on cold start, do a basic check first

• Check oil level and condition (low/dirty oil can affect chain tensioner operation).
• If the noise is only 1–2 seconds on cold start, that can point toward timing chain tensioner/cam phaser wear, but diagnosis should be confirmed before teardown.

Step 4: Decide the correct repair path

• If you meant the serpentine belt, tell me and I’ll give you the exact belt replacement steps for your Highlander.
• If you truly need timing chain work, I can walk you through the procedure, but it’s a major job requiring an engine support bar, coolant drain, and resealing the timing cover.

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✅ After Repair

• After any front-engine work, check oil level and coolant level, then run the engine and inspect for leaks.
• If a check engine light is present, scan codes and confirm they do not return after repairs.

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💰 DIY vs Shop Cost

Shop Cost: $1,800-$3,500 (parts + labor, timing chain/timing cover reseal related work)

DIY Cost: $300-$900 (parts only, depending on what’s actually needed)

You Save: $1,500-$2,600 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 10-16 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.

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Quick questions (so I give you the right procedure):

• 🔎 Did you mean the serpentine belt (external belt), or are you trying to address a timing chain issue?
• 🔎 What symptom do you have: oil leak, rattle/noise, or a check engine light (any code number)?