Lexus RX Engine Mount: Specs, Fitment & Common Faults

Confirmed: a genuine Technical Service Bulletin addresses an exhaust drone that can mimic a bad engine mount — plus an alarming, honest account of a vibration so severe and unresolved that Lexus itself acknowledged the issue without having a fix.

Illustration for editorial purposes

OEM Part Number: 12361-31470

Genuinely important to know: the engine code (not just the model name) is the reliable way to identify the correct RX mount, since the same model was often sold with several different engines across its production run, and mounts are rarely interchangeable between them.

RX450h hybrid, genuine transmission mount	Lexus OEM: 12361-31470

What It Does

Engine mounts secure the engine and transmission to the chassis while absorbing vibration and movement, preventing that vibration from transferring directly into the cabin. Most versions of the RX use several mounts working together — typically at least one on each side of the engine plus a torque mount — and a single failed mount can throw off the whole assembly's balance.

Fitment & Compatibility

Mount design and positioning differ between engine sizes and transmission types (manual versus automatic) of the RX. Always confirm the exact mounts fitted to your specific engine and transmission combination before ordering, since manual and automatic versions often use different mount designs even on the same engine. Whether you're sourcing a replacement engine mount for your Lexus RX from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying, and confirm you're ordering the correct side — driver's side (RH in the UK) or passenger side (LH in the UK) — since these are not interchangeable.

Confirmed: A Genuine Technical Service Bulletin Worth Checking First

If you're facing a vibration while accelerating on a 2016-2018 model specifically, this is genuinely worth checking before assuming the engine mount is at fault: a confirmed technical service bulletin addresses an exhaust drone issue that can feel remarkably similar to a bad engine mount, worth ruling out first since it's a genuinely different repair. It's also genuinely important to know before ordering a replacement front mount: the gas-engine mount, a specific part number, does not fit the hybrid variant at all, so it's worth confirming your exact powertrain before purchasing a replacement, since fitting the wrong one simply won't work.

A genuinely alarming, honest documented account worth knowing about how severe this can become: one directly documented case saw an engine mount replaced due to excessive vibration at low RPM, only for a very loud noise and vibration on acceleration to persist regardless — with Lexus reportedly aware of the situation but not yet having a solution at the time. The owner eventually gave up entirely and switched to a different manufacturer as a result. It's genuinely worth knowing this specific issue has been documented as severe enough to frustrate at least one owner into abandoning the brand, worth pushing for a proper, thorough diagnosis rather than accepting a straightforward mount swap if the vibration doesn't fully resolve.

It's also genuinely worth knowing some practical diagnostic points: shifting into neutral or park and seeing whether the vibration disappears is a useful way to help confirm a mount is genuinely the cause, since these mounts are fluid-filled, and a visual check for black or dark oily residue on the mount itself or the subframe beneath it can confirm a failure, as a leaking mount has lost its damping ability. Worth knowing these mounts have been documented leaking at surprisingly low mileage, sometimes as little as 57,000 miles.

Symptoms, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Engine Mount Guide for warning signs to watch for (including some genuinely make-specific quirks in how they show up), how difficult this job is to DIY, and which aftermarket approach is worth trusting.

More Lexus Engine Mount

The same part, covered across other Lexus models.