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Mercruiser Tilt And Trim Won’t Go Down – Ensure Efficient Operation

Mercruiser power tilt and the trim system

The mercruiser power tilt and the trim system helps to raise and lower the stern drive unit. And ensures efficient operation.

A number of holes in the gimbal ring were utilized in early stern drive units to provide a mechanical tilt system.

An adjustment stud put through the appropriate hole kept the device in place. So, when the Mercruiser tilt and trim won’t go down, what should you do?

There are many reasons why Mercruiser tilt and trim won’t go down. These include corroded end cap, imbalanced fluid level, electrical issue, and trim not functioning properly.

First and foremost, you must determine the actual cause. Then you easily solve the problem.

Well, that’s not all. To find out the reasons and solutions read the full article.

So why wait! Let’s dive in!

Reasons Behind Tilt and Trim Not Going Down

There are various reasons why the Mercruiser tilt and trim won’t go down. These reasons are mentioned briefly below. But before that, you should know about how to change the power trim & tilt fluid for Yamaha boats.

The end Cap Might Be Corroded

Suppose you rebuild your boat shifter and reinstall it. Everything appears to be working OK, however the trim would not retract.

In that situation, the first step is to locate the trim relays. After that, switch them with one another. One of the relays will be shot if it goes down instead of up.

When the end cap is corroded it will make a squealing noise. Do check if you hear any noise there.

Additionally, look for scrape marks on the piston rods. Both of these symptoms indicate that the end caps have rusted. They’re also clutching the rod.

Because the UP pressure is around 3000 psi, it will increase. The pressure is applied to the entire piston surface. Whereas the down pressure is about 1700 psi. And it operates only in half of the area.

This is because the piston is in the middle.

Electrical Issue

Mercruiser Electrical Issue

Many people who have 1979 Mercruiser 228 face this problem. They run the boat all day long without any problem.

But when they bring it to wash they see the trim won’t go down. Even the automatic stop doesn’t work sometimes.

When they hit the trim-up button they can hear the sound of the motor. But there is no sound when trimmed down.

If you hear the trim-up sound it rules out the chance of electrical issues. The trim might be just stuck.

To solve the problem, try standing on it. It will go down eventually.

Trim Is Not Functioning Properly

When you go out with your boat check everything is okay. Sometimes when you launch at the dock the trim motor is down. Fill up the reservoir with more fluids.

You can see that the trim is stuck. It won’t go down or up. You need to check the relays first.

Swap them out. If it still doesn’t work the reason might be that the trim is not functioning properly.

There might be air in the trim system. Keep working the trim motor until you see air purge from the reservoir.

If you want to know about Mercruiser ignition coil problems give it a read.

Imbalanced Fluid Level

Another reason for trim not going down can be an imbalanced fluid level. Many boat owners don’t focus much on the fluid level. As a result, they face this problem.

So you should consider that the fluid level may be low. You’ll have to stand on it to get the trim down in such scenario. And when it is down fill the trim with optimum fluid. It’s gonna be ok.

Trim Bypassing

bypass trim Mercruiser

You can try to bypass them if your trim isn’t going down. Now you might be asking how to bypass trim?

Well, it’s not that complex a task. Follow the below-mentioned method.

To begin, follow the line from the PTT electric motor to its connector. After that, unplug the wire.

Connect the two wires that run to the PTT motor with two short jumper wires from the battery.

The electric motor should run in one direction if the wires are connected in a certain way.

It should run in the opposite way if the wires are reversed.

It is possible that your engine has an outdated  PTT assembly. It is equipped with three wire electrical motors and doesn’t use connectors.

In the DOWN mode, voltage is transmitted from the PTT switch to the PTT motor.

The Blue wire connecting to the tiny terminal of the solenoid in the UP mode sends voltage to the solenoid within that junction box.

You could test it as follows if you or a buddy can temporarily detach the three wires leading to the electric motor. Take photos and make notes so you can rejoin the wires quickly later. Don’t put your trust on your memory.

Jumper wires are used to connect the battery to the electric motor. Connect the battery’s negative (Black) connector to the electric motor’s Black ground wire.

Then connect the battery’s positive (red) connection to the electric motor’s Blue wire, then to the Green wire. The color blue should cause the unit to rise.

The color green should cause the item to degrade. This test should disclose whether or not the electric motor is in good working order.

A failed solenoid valve or switch

A failed solenoid valve or switch in the tilt and trim system can cause the tilt and trim to not go down.

The solenoid valve controls the flow of hydraulic fluid in the system, and a failure in this component can cause the tilt and trim to become inoperable.

Symptoms can include:

  • No response from the tilt and trim system when the control switch is activated.
  • An audible clicking sound from the solenoid when the control switch is activated.
  • Intermittent operation of the tilt and trim.

To diagnose a failed solenoid valve or switch, a marine mechanic may use a multimeter to test the voltage and continuity of the solenoid circuit.

If the solenoid is found to be faulty, it will need to be replaced. It’s important to use the correct replacement solenoid for the specific make and model of the boat and tilt and trim system.

Clogged or damaged hydraulic lines or fittings

Clogged or damaged hydraulic lines or fittings in the tilt and trim system can cause the tilt and trim to not go down.

Hydraulic lines carry the pressurized fluid that operates the tilt and trim, and if they become clogged with debris or damaged, they can restrict the flow of fluid and cause the system to not function properly.

Symptoms of clogged or damaged hydraulic lines or fittings can include:

  • Slow or sluggish operation of the tilt and trim.
  • A noticeable reduction in the tilt and trim’s speed or power.
  • Leaks or dripping from the hydraulic lines.

To diagnose clogged or damaged hydraulic lines or fittings, a marine mechanic may inspect the lines and fittings for signs of wear or damage, such as cracks, leaks, or clogs.

If any issues are found, the damaged parts will need to be replaced. It’s important to use the correct replacement parts for the specific make and model of the boat and tilt and trim system.

In some cases, a flush of the hydraulic system may be required to clear any clogs and restore proper operation.

If you want to know more about tilt and trim troubleshooting read this article.


Mercruiser faqs

Why Won’t My Trim Go Up on My Boat?

It’s possible that the issue is with the hydraulic pump. To solve the problem, start checking by hydraulic reservoir level.

If the level is okay the problem could be with valve assembly. A low-level fluid indicates a leak in seals.

How Do You Manually Lower A Mercruiser Outdrive?

Unscrew the nut on a Mercruiser outdrive to manually lower it. Then remove the large washer.

Wiggle the shaft that passes through from the opposite side out while trying to pull it out. To get it started, you may need to tap it with a hammer.

How to Manually Lift or Lower Your Inboard Engine?

Reach to the very backstage of the boat. Two metal pins connecting the shaft to the trim motor should be visible. To remove the pins from the trim motor, use a wrench.

Remove the lock pins from the motor and insert them into the trim settings in the cowling region

What should I do if I can’t diagnose the issue with my Mercruiser Tilt and Trim?

If you’re unable to diagnose the issue with your Mercruiser Tilt and Trim, it’s recommended to seek assistance from a trained marine mechanic or authorized dealer, using proper diagnostic equipment and following manufacturer guidelines.


We are at the very end of the article. Hopefully, you know the reasons why Mercruiser tilt and trim won’t go down.

After you find out the reason, do according to the measures mentioned above. It’s not a difficult task. You can simply complete it on your own.

Best of luck.

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