Trim Cylinder Overhaul Kit – Fits Mercury MerCruiser MC-I Sterndrives (Replaces 45522A3)
Trim Cylinder Overhaul Kit – Fits Mercury MerCruiser MC-I Sterndrives (Replaces 45522A3) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Trim Cylinder Overhaul Kit – Fits Mercury MerCruiser MC-I Sterndriv...
Product Details
This aftermarket Trim Cylinder Overhaul Kit is designed for a wide range of MerCruiser MC-I sterndrives from 1970 to 1982. It fits various models including the 120/140, 165, 225-S, 233, 250, 260, 470, 485, 888, and 898 series.
It serves as a direct replacement for Mercury OEM part number 45522A3.
- Designed for direct OEM replacement installation.
- Includes all necessary components for a complete overhaul.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 45522A3 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser Engines: Please verify your model and serial number range against the data below to ensure an exact match.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 120/140 | 120/140 | 4-Stroke | 1970–1977 | 45522A3 | Serial Numbers: 2791957 THRU 4893634 |
| MerCruiser | 120/140 | 120/140 | 4-Stroke | 1978–1982 | 45522A3 | Serial Numbers: 4893635 THRU 6225576 |
| MerCruiser | 165 | 165 | 4-Stroke | 1970–1977 | 45522A3 | Serial Numbers: 2763442 THRU 4890459 |
| MerCruiser | 165 | 165 | 4-Stroke | 1978–1981 | 45522A3 | Serial Numbers: 4890460 & Up |
| MerCruiser | 225-S | 225 | 4-Stroke | 1974 | 45522A3 | Serial Numbers: 3856268 THRU 4200499 |
| MerCruiser | 228 | 228 | 4-Stroke | 1977 | 45522A3 | Serial Numbers: 4782330 THRU 4898729 |
| MerCruiser | 228 | 228 | 4-Stroke | 1978–1982 | 45522A3 | Serial Numbers: 4898730 THRU 6225576 |
| MerCruiser | 233 | 233 | 4-Stroke | 1975–1977 | 45522A3 | Serial Numbers: 4200500 & Up |
| MerCruiser | 250 | 250 | 4-Stroke | 1977 | 45522A3 | Serial Numbers: 4791300 THRU 4898729 |
| MerCruiser | 260 | 260 | 4-Stroke | 1978–1982 | 45522A3 | Serial Numbers: 4898730 THRU 6225576 |
| MerCruiser | 470 | 170 | 4-Stroke | 1976–1977 | 45522A3 | Serial Numbers: 4208730 THRU 4893934 |
| MerCruiser | 470 | 170 | 4-Stroke | 1978–1982 | 45522A3 | Serial Numbers: 4893835 THRU 6225576 |
| MerCruiser | 485 | 185 | 4-Stroke | 1980–1982 | 45522A3 | Serial Numbers: 4893835 & Up |
| MerCruiser | 888 | 330 | 4-Stroke | 1971–1977 | 45522A3 | Serial Numbers: 3106717 AND UP |
| MerCruiser | 898 | 330 | 4-Stroke | 1977 | 45522A3 | Serial Numbers: 4782330 THRU 4898729 |
| MerCruiser | 898 | 330 | 4-Stroke | 1978–1982 | 45522A3 | Serial Numbers: 4898730 THRU 6225576 |
Technical Specs
- Product Type
- Trim Cylinder Overhaul Kit
- Installation
- Direct OEM replacement
- Package Weight
- 0.54 kg (1.20 lb)
- Package Dimensions
- Length: 5.0 in, Width: 5.0 in, Height: 33.5 in
- Warranty
- 1-Year Manufacturer Warranty
What’s in the Box
- 1 x Trim Cylinder Overhaul Kit (replaces 45522A3)
Installation Notes
- Ensure the engine is off and the sterndrive is in the fully down position. Disconnect the battery.
- Place a drain pan under the trim cylinders to catch any hydraulic fluid.
- Carefully disconnect the hydraulic lines from the cylinders. Be prepared for fluid spillage.
- Remove the upper and lower cylinder hinge pins to free the cylinders from the gimbal housing.
- Take the cylinder to a clean workbench to begin disassembly.
- Use a pin wrench to remove the end cap. Do not use a pipe wrench, as it can damage the cylinder.
- Carefully slide out the piston rod assembly, keeping all components in order.
- Remove the old seals from the end cap and piston, then clean all components thoroughly.
- Install the new seals from the kit, ensuring they are properly seated and lubricated with fresh hydraulic fluid.
- Reassemble the cylinder, torquing the end cap to the manufacturer's specification.
- Reinstall the overhauled cylinders onto the sterndrive, reconnect hydraulic lines, and torque all fasteners properly.
- Fill and bleed the power trim system according to your service manual, then check for leaks and proper operation.
Troubleshooting & FAQ
How do I know if this kit fits my specific MerCruiser sterndrive?
This kit is designed for MC-I sterndrives. The most reliable way to confirm fitment is to check your engine's serial number against the ranges listed in the Engine & Model Compatibility table.
What are the signs that my trim cylinders need to be overhauled?
Common symptoms include the sterndrive drifting down, jerky or slow trim operation, or visible hydraulic fluid leaks around the cylinder seals or lines.
Does this kit include hydraulic fluid?
No, hydraulic fluid is not included. You will need to use a fluid that meets the specifications recommended by your engine's service manual.
Is a special tool required for installation?
While many steps can be completed with standard garage tools, a pin wrench is highly recommended to safely remove and install the cylinder end cap without causing damage.
What is the difference between OEM and aftermarket parts?
This listing is for an aftermarket replacement, not an OEM part. It is built to the same or higher specifications as the original, often in the same factories, using comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for quality and consistency.
How fast do you ship and what does it cost?
We ship worldwide, with most orders arriving within 5–15 days. Standard shipping is typically free, with expedited options available at checkout for an additional cost depending on your location.
What is the warranty and return policy?
This product is covered by a 1-year warranty against any manufacturing defects under normal use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard returns window for unused items in their original packaging. Please see our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an original equipment manufacturer (OEM) part.
- Professional installation is highly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
Payment & Security
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