# 27991734 Mercury MerCruiser Gasket | Genuine Quicksilver OEM Part

## 🔧 Product Description

**Genuine Quicksilver Driveshaft Housing Gasket - Part Number: 27-991734**

A genuine Quicksilver driveshaft housing gasket used on selected Mercury and Mariner V6 2-stroke, EFI, DFI / OptiMax, Jet and high-performance outboard midsection assemblies. This gasket seals the driveshaft housing to the driveshaft housing plate / exhaust plate area.

## ⚙️ Key Features

-   Genuine Quicksilver OEM driveshaft housing gasket
-   Correct Mercury part number 27-991734
-   Used in V6 outboard midsection / driveshaft housing assemblies
-   Commonly listed with 27-991764 cylinder block gasket in powerhead and lower-unit gasket set components
-   Important replacement during powerhead, driveshaft housing or exhaust plate service

## 🚤 Compatibility

### Commonly used on

-   Mercury / Mariner V6 driveshaft housing and exhaust plate gasket applications

### Typically suits

-   Engine models:
-   Mercury V-135 DFI 2.5L - serial 0T801000 to 1B226999
-   Mercury V-135 DFI 2.5L - serial 1B227000 to 1B417701
-   Mercury V-135 DFI 2.5L - serial 1B417702 and up
-   Mercury V-150 DFI 2.5L - serial 0T801000 to 1B226999
-   Mercury V-150 DFI 2.5L - serial 1B227000 to 1B417701
-   Mercury V-150 DFI 2.5L - serial 1B417702 and up
-   Mercury V-175 DFI 2.5L - serial 0T801000 to 1B226999
-   Mercury V-175 DFI 2.5L - serial 1B227000 to 1B417701
-   Mercury V-175 DFI 2.5L - serial 1B417702 and up
-   Mercury V-150 EFI 2.5L - serial 0T801000 to 1B226999
-   Mercury V-150 EFI 2.5L - serial 1B227000 and up
-   Mercury V-200 EFI 2.5L - serial 0T801000 to 1B226999
-   Mercury V-200 EFI 2.5L - serial 1B227000 and up
-   Mercury XR-6 / Magnum III engine gasket set applications - serial 0G960500 to 1B226999
-   Mercury 150 Pro XS 2.5L - serial 1B690542 to 2B535572
-   Mercury 175 Pro XS 2.5L - serial 1B516339 to 2B535624
-   Mercury 200XS DFI 2.5L - serial 0T818181 to 1E000796
-   Mercury 200XS DFI 2.5L - serial 1E000797 to 1E002110
-   Mercury 200XS ROS DFI 2.5L - serial 1E050852 and up
-   Mercury 200XS SST - serial 1E050629 and up
-   Mercury 105 Jet / 140 Jet 2.5L V6 driveshaft housing applications where 27-991734 is specified
-   Mercury 105HP to 225HP V6 drive housing plate applications where 27-991734 is specified
-   HP Range: commonly 105 Jet through 225HP V6 applications where specified
-   Engine Type: Mercury / Mariner V6 2-stroke, EFI, DFI / OptiMax and Racing outboard
-   System Type: Driveshaft housing to driveshaft housing plate gasket

## 🔌 Function

The gasket seals the driveshaft housing interface, helping prevent exhaust leakage, water leakage and contamination at the midsection / exhaust plate area.

## ⚠️ Common Signs of Failure

-   Exhaust leakage from midsection
-   Water leakage around driveshaft housing joint
-   Gasket damaged during powerhead or midsection removal
-   Corrosion or residue around gasket surface
-   Replacement required during exhaust plate or driveshaft housing service

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   27-991734 current OEM service reference
-   27-991733 / 27-991732 / 27-991731 related earlier gasket-family references where applicable

### OEM / Related Numbers

-   27-991734
-   991734
-   27991734
-   27-99173-4
-   27-991733
-   27-991732
-   27-991731
-   27-183076 related driveshaft housing plate gasket
-   26-38970 related seal
-   27-991764 related cylinder block gasket

### Aftermarket / Verified Equivalents

-   WSM: 510-30 related drive housing gasket reference

## 📦 Condition

-   Genuine Quicksilver part
-   Brand new
-   Supplied in original or equivalent packaging

## Details

- **Price:** 50.4 AUD
- **Vendor:** Quicksilver
- **Type:** Gaskets & Seals
- **Tags:** Quicksilver Marine Parts | Oils, Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 50.40 AUD | In stock |

## Images

- 27991734 Mercury MerCruiser Gasket | Genuine Quicksilver OEM Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/27991734-mercury-mercruiser-gasket-genuine-quicksilver-oem-part)
> Updated: 2026-09-06