Mercury MerCruiser — 7/16-20 x 1-1/2 in. Flange Screw — 805159
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Mercury MerCruiser Flange Screw 805159 | 7/16-20 × 1-1/2 in.
The Mercury MerCruiser 805159 is a genuine OEM 7/16-20 × 1.500 in. flange-mounting screw used in select MerCruiser transmission and driveline assemblies. Mercury parts diagrams show it securing 5-inch transmission flange assemblies, including Hurth and Borg Warner transmission installations.
Compatible Applications
- Hurth 630 / 800 transmissions
- Borg Warner 5000 transmissions
- 5-inch transmission flange configurations
- 350 MAG MPI MIE
- 5.7L MPI MIE
- 6.2L MX MPI Horizon
- 8.2L inboard
Confirm your engine serial number, transmission model, and flange diameter before ordering. MerCruiser diagrams use different screws for 4-inch and 5-inch flanges; 805159 is specifically shown with the 5-inch flange configuration.
Part Details
- Part number: 805159
- Full service number: 10-805159
- Brand: Mercury Marine
- Official product type: Transmission flange screw
- Thread: 7/16-20
- Length: 1.500 in. / 38.1 mm
- System: Transmission / driveline
- Typical quantity: 4 per flange assembly
Related Parts
- 32993 — 7/16 in. lock washer, used with this screw
- 79476A-series — 5-inch flange assemblies
- 68101 — Screw used with applicable 4-inch flange instead
When This Part Needs Replacement
Replace the screw if the threads or head are damaged, corrosion is significant, or it cannot be tightened correctly. Inspect all flange fasteners whenever the transmission coupling is serviced.
Installation Notes
Install with the correct flange, lock washer, and related hardware shown in the Mercury diagram. Applicable assemblies use lock washer 32993 with 805159. Tighten according to the MerCruiser service specification for the specific transmission and flange assembly.
Alternate/Superseded Part Numbers
- 805159 — current OEM part number
- 10-805159 — full Mercury service number
- 52498 / 10-52498 — superseded by 805159
Technical FAQ
How many screws does a flange assembly need? Diagrams typically call for 4 per flange assembly.
Does this fit a 4-inch flange? No. If you are working on a 4-inch flange configuration, MerCruiser specifies a different screw (68101); 805159 is for the 5-inch flange.
Parts Desk Insights
Best use case: This screw is the right fastener when servicing a MerCruiser transmission coupling that uses a 5-inch flange, such as applicable Hurth or Borg Warner installations.
Common mistake: The most common mistake is selecting a fastener by length alone. MerCruiser uses a different screw for 4-inch flanges, so matching the flange diameter and OEM number is more reliable than matching thread length.
Sizing and fitment: If you are unsure whether your transmission uses a 4-inch or 5-inch flange, confirm against your engine serial number and parts diagram before ordering, and replace lock washer 32993 alongside this screw.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
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:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.