2006 Alpha 1 stuck in up position.

4.3L owner

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Feb 13, 2014
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My Alpha 1 drive unit is stuck in the up position. When I press the down arrow on my shift control the pump motor sounds like it is working and the hydraulic lines flex but the drive unit remains in the upright position. The hydraulic motor tank is full of oil. I welcome any input that will lead to a resolution of this issue. Thanks in advance for your help
 

Alumarine

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Feb 22, 2005
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Try removing the rams from the back of the drive.
See if this allows the drive to come down.
Also, run the pump down then up and see if both rams move in and out.
Does the pump make the same noise as it used to?
 

alldodge

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My Alpha 1 drive unit is stuck in the up position. When I press the down arrow on my shift control the pump motor sounds like it is working and the hydraulic lines flex but the drive unit remains in the upright position. The hydraulic motor tank is full of oil. I welcome any input that will lead to a resolution of this issue. Thanks in advance for your help

Most probable cause is your hydraulic rams are binding inside. Remove the lines and see if it will go down, if it doesn't need to replace or rebuild the rams
 

achris

More fish than mountain goat
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May 19, 2004
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Get someone to jump up and down on the drive while you're pressing 'IN'.... (No, it won't hurt the drive).... Once you have the drive down, replace the end caps on the rams... Very common problem.... And then, don't store the boat with the drive UP.....

Chris..........
 

4.3L owner

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Feb 13, 2014
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Thanks for all the great suggestions. I will try them this week. I wonder if my mother in law is game for jumping up and down on the drive. She is arriving tonight for a weeks visit. I'll keep you posted.
Thanks again,
4.3L Owner
 

TexMonty

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Dec 26, 2014
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I had the exact same thing happen out of the blue a month ago and everyone here was dead on. It was the rams. I chose to buy new rams (they are not very expensive) and then I rebuilt the old as spares since it sounds like it is a common problem.
 

wrench 3

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An oil seal leaking on the inside of a ram will also have this affect. It has to build pressure in the down side to release the lock on the up side. It can't do that if it's leaking into the other side. If this is the problem, loosening the lines will let it drop. If you remove the up lines and hit the control down, you will get fluid coming out of the port on the bad cylinder without the ram moving.
 

ziggy

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Jun 30, 2004
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My Alpha 1 drive unit is stuck in the up position.
The hydraulic motor tank is full of oil
the other posters have more experience than i do, but i don't think the reservoir should be full when the drive is up. best i know, ya fill the reservoir when the drive is down. when the drive goes up, the fluid is then in the trim rams. the reservoir would be low on fluid. if the drive is up, and the reservoir is full, there'd be no where for the fluid to go when bringing the drive down since the reservoir is full.
just a thought.
 

Bt Doctur

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Aug 29, 2004
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Dosent matter ,ziggy. once properly filled the level dosent change. A last ditch effort would be to reverse the 2 lines at the pump. The is more pressure generated going up then going down.
 

wrench 3

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The manual says to check and fill the reservoir with the drive all the way down. It makes seance to me since the rams hold less fluid when they're retracted.
 

UncleWillie

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Oct 18, 2011
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When the rams are DOWN, the Ram Rods occupy some of the space. The UP side of the pistons are 100% fluid.
The reservoir will contain more fluid when the rams are DOWN.
The fluid level change in the reservoir doesn't go from full to nearly empty, but it does change some.
 

achris

More fish than mountain goat
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The FULL level/mark on the trim pump reservoir on the Oildyne pumps (used on Gen II drives) has enough 'head room' to not matter in this case. And even if the reservoir were 'overfull', the excess fluid would just leak out of the air bleed hole in the cap.

Chris.....
 

achris

More fish than mountain goat
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Messages
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An oil seal leaking on the inside of a ram will also have this affect. It has to build pressure in the down side to release the lock on the up side. It can't do that if it's leaking into the other side. If this is the problem, loosening the lines will let it drop. If you remove the up lines and hit the control down, you will get fluid coming out of the port on the bad cylinder without the ram moving.

Sorry Wrench3... I agree with you on most things, but not this one....

Let's start with the first part. If a seal/'O' ring is leaking allowing pressurised oil across the piston, then that pressurised oil would be enough to open the UP side valve. Thus it would not stop the drive from lowering. Even if it didn't, the pressurised UP side on the other ram would be enough to open the valve. (Remember, the lines are in pairs split at the manifold under the gimbal housing.)

Second part. If the leak was big enough for the oil to flow from the open UP port without the ram moving when the DOWN switch was pressed, it would drop on its own, without any input from the pump. Most internally leaking seals/'O' rings leak a very small amount, and the only sign that you have a leak is that the drive SLOWLY drops down by itself.

A drive that will not move under pump power is usually because of some external force (like a jammed ram or a locked piston)...

Chris........
 

wrench 3

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Sorry Wrench3... I agree with you on most things, but not this one....

Let's start with the first part. If a seal/'O' ring is leaking allowing pressurised oil across the piston, then that pressurised oil would be enough to open the UP side valve. Thus it would not stop the drive from lowering. Even if it didn't, the pressurised UP side on the other ram would be enough to open the valve. (Remember, the lines are in pairs split at the manifold under the gimbal housing.)

Second part. If the leak was big enough for the oil to flow from the open UP port without the ram moving when the DOWN switch was pressed, it would drop on its own, without any input from the pump. Most internally leaking seals/'O' rings leak a very small amount, and the only sign that you have a leak is that the drive SLOWLY drops down by itself.

A drive that will not move under pump power is usually because of some external force (like a jammed ram or a locked piston)...

Chris........

To start off with let me say that I ran into that scenario two seasons back.
With the system basically at rest the both lines are connected to opposite sides of the pump. when the pump spins in the down direction the up lines are on the suction side of the pump. Since the lines are teed under the gimbal housing, loose pressure on one line and the other line drops also.
The pump locks the drive in position by closing off the return to the reservoir, and as we have established earlier here, the rams have to displace fluid to retract. Until the shuttle valve moves the system won't "vent" to the reservoir.
I hope this clarifies it a bit.
I'm also not saying that seized rams may not be a problem but with no salt water around here I don't run into very many.
 

wrench 3

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How did you happen to diagnose your findings wrench 3?

For the most part I got lucky.
I don't have a gauge with the proper valve manifold so was connecting the gauge directly to the test point and plugging whatever needed to be closed. I had the up line off of the one cylinder so capped the line and did not see a reason to plug the cylinder port. When I removed the support from under the drive it free fell. Since it would not drop with the line hooked up, I concluded that it was venting through the cylinder. To test the theory I fully retracted the cylinder and hit the down button.
Then I got out the hydraulic diagrams for the system and tried to find out why that would stop the system from lowering. (I'm a little compulsive when it comes to understanding the why of things.:biggrin1:)
 

4.3L owner

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Feb 13, 2014
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Problem is fixed. I removed one line to make sure the pump was working properly. Once I determined it was I lubricated the exposed ram rods and then climbed on the swim platform. Once there I stood on the lower unit and shifted my weight up and down while depressing the trailering button for raising and lowering the drive unit. Once it started to move I knew I had the problem fixed. This site is fantastic and it is only because of individuals like you.
Thanks to everyone who posted fixes to my problem. You were a great help.
All the best,
4.3L owner
 
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