Alpha trim ram frozen

[GJarrett]

The right trim ram on my Alpha 1 outdrive is frozen in the extended/up position (it worked normally one month ago). When operating the trim, the left side ram works fine.... when I removed the right ram the left one was able to raise and lower the drive normally. I tried twisting the piston, letting some fluid out and trying to push it down, etc all to no avail. Any help would be appreciated... is it easy to disassemble the ram and hopefully perform an easy fix, or what?

 

[annie]

You need a special tool to undo the cap under the anode (you can make one out of plate metal and 4x 3/16 screws or bolts). I take it the leg wouldn't trim up and down which led you down this road.....The reason I ask is it's normal for one ram to operate when they are disconnected at the leg.

 

[GJarrett]

Thanks... I'll go find a spanner tool to unscrew the cap. I have never looked into one of these things. Can someone give me tips and instructions on disassembling the piston/cylinder of the ram, and where to get parts if needed?

 

[dev6315]

I will check my SELOC manual for you later when I can get to the shop but I believe there is a write up on servicing these. I would think parts should be readily available as they are very common. At the least, it is a hydraulic ram, worst case you could take it to a hydro shop that deals with machinery and heavy equipment and they could service it for you. I have had luck in the past with such a shop. I believe it was a Cleveland Brothers CAT shop. Very knowledgeable.

 

[Bucit]

I belive it's cheaper to replace them than it is to rebuild them. Check out http://www.sterndrive.cc/mm5/mercha...tegory_Code=MercruiserAlphaGenIITrimCylinders

They are $120 each for new rams.

 

[Gunn]

The right trim ram on my Alpha 1 outdrive is frozen in the extended/up position (it worked normally one month ago). When operating the trim, the left side ram works fine.... when I removed the right ram the left one was able to raise and lower the drive normally. I tried twisting the piston, letting some fluid out and trying to push it down, etc all to no avail. Any help would be appreciated... is it easy to disassemble the ram and hopefully perform an easy fix, or what?

Both of my sterndrive units had this same problem! With the drive units left up for an extended period, they were very difficult to get down. My boat spent a couple weeks on a boat lift after a bad storm with the drive's full up to prevent contact with the waves. I couldn't lower them. I had to get the boat home somehow to fix the problem. I ended up using a ratchet strap with all my might, while my wife pulsed the down trim button to get them down. They went up no problem.

The problem for me was corrosion in the trim cylinder cap around the scraper ring that scraps bad stuff off of the shafts as the retract into the cylinder. Corrosion had built up around this area making it extremely difficult to move. A couple of these scraper rings were even bent in a concave manner due to the force being exerted to retract them.

This cap is the one where you need the spanner wrench. I used a typical spanner wrench with two contact points to remove them. They turned and unscrewed pretty easily but were near impossible to get off of the shaft. After suffering through removing one from the shaft in a bench vise, I took the other three cylinders to a friends house who had a 20ton press. They came off easy with that. :smt001

I took a bunch of photos that I can add later. But it's a simple job to rebuild them. Remove the caps, pull out the remainder, replace all of the O-rings and re-install. The caps were around $50 each I think, and the rebuild kit was around $18 each (total rebuild cost = ~$68). They have worked great ever since, including the first ride of the season this year after sitting for several months.

Tom

 

[Gunn]

I took a bunch of photos that I can add later.

Here are the photos I mentioned, in order of disassembly/assembly. First one is what you'll have once you use the spanner wrench to remove the end cap.

Also inside the cylinder, a floating piston will fall out. Remember the direction it is facing so you can re-install it the same way.

Here is what my end caps looked like once I removed them using a press (they would not budge off the shaft otherwise!):

You don't have to disassemble the unit on the end of the shaft...but I did just to see how it was put together and how it operated.

Note that the large spacer/washer right next to the bolt on the left side of the pic can be removed. This will allow the stern drive to tuck in more into the full down position, allowing the bow to come down more. I removed these spacers on my boat so I could get the bow down more at slower speeds while on plane. While I do think it helped a bit in that scenario, it's not as noticeable as I had hoped.

The floating piston will go back into the cylinder in this direction:

And finally, the completed unit all rebuilt, ready for re-install.

And there you. Slide it all back in and tighten with the spanner wrench. You'll have to bleed the system as you refill the trim pump with fluid. You'll need a helper to activate the trim switches for this step.

Good luck if this is indeed your problem. But I'm betting on it...

Tom

 

[GJarrett]

Thank you so much for the information! I will try unscrewing the endcap and seeing if I can get lucky and clean/free the scraper ring. If it's in really bad shape I might just replace it with a $120 unit (I don't have access to a multi-ton press). If it is in bad shape I may replace the portside one too on the assumption that it is in similar shape... I don't want this to happen at an inopportune time on a cruise.

 

[KP49]

Thanks for the 120.00 a ram link.

Mine is sticking (going down only, goes up fine) after a couple weeks of non-use on the lift as well, I have to trim the drive up a little to keep the skeg out of the water so at least if it gets stuck there I can still drive the boat on the trailer if I had to. So far its always freed up after a few up-downs on the switch but next time its on the driveway I'll try to take them apart, cheap enough to replace if I screw them up.

 

[Bucit]

When the end caps start going you can trim them up but they get stcuk on the way down. If they're not too bad you can clean the ends and the ram then spray PB Blaster on them. You will have to do this every couple of weeks but it will get you by in the meantime.

 

[GJarrett]

Got the endcap off with a spanner wrench. That puppy is STUCK and very corroded. I think I'll simply buy new ones.

The part number of the trim cylinders I have are 815935-1 port side and 815954-1 starboard side. However the link to the replacement assemblies linked by Bucit are listed as matching 815954A 7 and 815935A 7. Are the rams designated with part numbers ending in "A7" the same/interchangeble with mine that end with "-1"?

Finally, would someone tell me how to bleed the system correctly to fill it up with fluid once I replace these rams?

Thanks again for all of your help.

 

[Bucit]

Not sure on part numbers but I would just call them and tell them what you have. They will know for sure.

 

[Gunn]

Got the endcap off with a spanner wrench. That puppy is STUCK and very corroded. I think I'll simply buy new ones.

The part number of the trim cylinders I have are 815935-1 port side and 815954-1 starboard side. However the link to the replacement assemblies linked by Bucit are listed as matching 815954A 7 and 815935A 7. Are the rams designated with part numbers ending in "A7" the same/interchangeble with mine that end with "-1"?

Finally, would someone tell me how to bleed the system correctly to fill it up with fluid once I replace these rams?

Thanks again for all of your help.

As I recall, the last number is just a revision number...meaning they've made improvements or fixes to it, but are completely interchangeable and will fit in the same way, same space, etc. You won't be able to find a previous revision (or the original as you have).

The bleed procedure is the Mercruiser service manual. They manual is something worth having. I don't recall the details, but if I get a chance I can list them. You basicaly remove one hose and then operate the tilt switch until a steady stream of fluid comes out. It'll squirt quite a distance! It just completely shot past my catch bucket. Grass grew back in a couple months... :smt001

You sure you want to buy new ones? Get that thing off somehow and save yourself over 50%... :smt001 Vise, press, cutoff wheel, friend.

 

[GJarrett]

I won't have time or ability to muscle and force the stuck cap(s).... I am recovering from double hernia surgery and don't want to take any chances. I had to get help just to twist the spanner wrench. And the Admiral wants us splashing soon. By the time I bought a press and the rebuild kits, the price won't be much different from the $120 Sterndrive units, so I simply ordered them today with expected delivery Saturday.

I asked about the part numbers because the first salesperson I talked to didn't know (must be new or something). I did find one that knew their products this morning and got a confirmation of your answer - I won't be able to find a matching part ending in "-1" and the "A7" is a direct replacement.

Thanks for your help - I'll be completely fixed for $240 which I am confident is less than the local Sea Ray shop would have charged me just to look at it.

 

[Gunn]

Good to hear. You'll be back on the water in no time. Keep us updated once you install the new one's.

Tom