Mercury MerCruiser Bracket 18903T
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Mercury MerCruiser 18903T is a genuine OEM rear bracket used in transmission and engine mounting assemblies on a wide range of MerCruiser inboard gas engines. Current Mercury dealer references show 18903T as superseded to 18903T02, which is the current functional replacement part number.
Key Features
- Genuine Mercury MerCruiser OEM part number 18903T, superseded to 18903T02.
- Current Mercury dealer description identifies it as BRACKET (REAR).
- Used in transmission and engine mounting layouts, including Hurth 630 applications.
- Current dealer listing shows GTIN 745061124905.
- Current shipping specs are approximately 5.06 lb, 4.50" L x 3.25" W x 11.00" H.
Engine Compatibility
Current Mercury dealer where-used references connect this rear bracket to a broad range of MerCruiser inboard engine applications, including 5.7L MIE, 5.7L EFI MIE, 350 MAG MPI MIE, 350 MAG MPI Horizon MIE, 7.4L MIE, 7.4L MPI MIE, 8.1L Inboard, 8.2L MIE, and MX 6.2L MPI MIE / Horizon MIE families. Current OEM diagrams also show 18903T in Transmission and Engine Mounting (Hurth 630) breakdowns on 7.4L and related inboard applications.
Serial Number Fitment Notice
Verify fitment by exact engine serial number and the correct transmission / engine mounting diagram before ordering. This bracket appears across many MerCruiser inboard applications, so the safest match is the serial-specific parts breakdown rather than engine family name alone.
When This Part Needs Replacement
Replace this bracket when the original is cracked, bent, heavily corroded, or no longer supports the engine/transmission mounting arrangement correctly. Because this is a structural mounting bracket used in the rear engine/transmission support area, condition and exact fit matter more than appearance alone. This replacement guidance is a practical service inference based on its documented role in transmission and engine mounting assemblies.
Installation Notes
Install this part only after confirming the correct MerCruiser mounting diagram for the engine and transmission being serviced. Current OEM diagrams show the rear bracket used with related mounting hardware including M12 x 45 screws, lockwashers, nuts, and the related front bracket 66418T in Hurth 630 mounting layouts.
Alternate/Superseded Part Numbers
Current Mercury dealer references show 18903T02 as the active replacement for 18903T.
Parts Desk Insight
With mounting brackets like this, the exact mounting system and transmission layout matter more than the bracket name alone. Matching the rear bracket to the correct serial-number-based mounting diagram is the best way to avoid getting the wrong support bracket for the engine package.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
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