How to make the transom locker door open to full height on 360/370

LaRea

This post shows how to replace the lift springs on a 360/370 EC transom locker with longer springs so the hatch opens to full height. 

Difficulty:  Easy

Time to complete:  3-4 hours (45 minutes if the door needs no reconditioning)

Like many larger Rinker cruisers, my 2007 370 has a transom locker that opens to the swim platform.  From the factory, the door would only open halfway, so I had to get down on my hands and knees to use the locker.  Here's the original geometry:

If there's a good reason for that design, I've never figured it out.  Today I replaced the springs with longer ones, and BOOM -- now it opens to a full six feet high!  No more stooping over with heavy objects.  

The part I used is an Attwood model SL27-40-01 (two required - Great Lakes Skipper carries them).  The load capacity is 40 pounds per spring (same as the OEM springs).  They fit right onto the existing 10-mm ball mounts.  Length 28 1/2" when extended, 17" when compressed.

The installation procedure depends on the condition of your door.  Does the inside of your door have dark drip trails under the mounts?  If yes, your fittings have developed leaks, and you have water inside your fiberglass like I did!  You need to remove the door and address the water issue.  

Even if your door is not leaking (yet), it might not be a bad idea to re-bed the hardware anyway.

Here's the first part of the process:

1)  With a helper holding the door, remove the original springs from the ball mounts.  Use a small flat screwdriver to pry up the release at the end of the spring, and it will pop right off with very little force.

2)  Remove the lower ball mounts from the door frame, and fill the screw holes with 3M 5200 or other sealant.  

3) Reinstall the lower ball mounts so that the lowest screw is 5" from the bottom of the door opening.  (NOTE -- MEASURE YOUR BOAT AND YOUR NEW SPRINGS CAREFULLY!  THIS IS THE DIMENSION THAT WORKED ON MY BOAT, BUT PLEASE DO NOT TAKE MY WORD FOR IT.)  Dab some 5200 in the screw holes and on the screw threads before installing them.

4)  With a helper holding the door, install the new gas springs.  They snap onto the ball mounts -- no tool required.  Test to make sure the door opens and closes properly. 

If you aren't removing the door, you're done!  If your door needs work, here's what to do:

5)  Disconnect the springs from the door, then remove the door by removing the four screws that hold the hinges to the door.

6)  With the door sitting on a table or bench, remove the grab rail and the two upper ball mounts from the door.  

7) If the inside of your door is stained with nasty blackness like mine was, now's the best time to clean it.  I had already tried every type of spray-and-wipe cleaner without success.  But with the door off, I went to the nuclear option:  Bar Keepers Friend with a Scotchbrite sponge.  I still didn't get it 100% clean, although it is much better than before.  Eventually, I might paint it gloss white.

8)  If your fittings have leaked water into your door, get that stuff out of there!  I spent about an hour with a shop vac and an air compressor getting as much as I could.  Try holding the shop vac to one screw hole while blowing compressed air in another.  Keep going until you can't get any more water.  

9)  Reinstall the grab rail using butyl tape (my favorite sealant) inside and out. Do not overtighten the nuts.  Reinstall the ball mounts using 3M 5200 in the screw holes and on the screw threads.

10)  With a helper, reinstall the door and admire your handiwork.

aero3113

Nice work!

Cableguy Greg

Very nice! I always wondered why my 280 only opened halfway as well. I might have to look into this.

NavyCTRC

You forgot a step...

- step back admire your work!

- Open a cold beer and drink it, ...while opening and closing the door a hundred times to make sure you got it right....

at least that is how I finish a project...

Good job!  This project is one I need to do desperately!! 

BellevilleMXZ

Very Nice!! I can see why you changed it, poor design

Dream_Inn

Very nice and detailed very well with pictures!  It's topics like this that make this forum so fantastic!  Thanks LaRea!!

randy56

Great instructions, Great improvement, It's useable now.

Handymans342

Do you think the water infiltration did any damage?

LaRea

Structurally, I think it's fine.  It's not a highly stressed part.  There's some cracking of the gelcoat on the inside ... probably freeze damage, which is the main reason I wanted to get the water out.  

If anybody does this mod on other Rinker models, I hope they'll post the details here!

wheatst

Nice...I passed this on to our Engineering department.

jme097

I am definitely doing this to my 280. Taking measurements this weekend while at the boat 

LaRea

@wheatst - so far, the only (minor) drawback is that when the lid is up, it partially blocks the view from the cockpit.  There's no other interference with the canvas or anything else.  Over the next week, I'll have more time for testing.

Handymans342

I could think of a lot of things that need to go to the Engineering dept. 

LaRea

Bonus feature:  the door now makes a really nice sun shade for the swim platform bench seat.  The Admiral and I sat there for a while yesterday in our slip on the T-pier.  Every boat that came by commented on what a nice little oasis we had!

YYZRC

Awesome! Do you think a 30 pound shock would work? I can’t find a 40 pound. 

LaRea

I'd guess it will work.  The hatch isn't all that heavy.  

aero3113

@YYZRC , contact the eBay seller in my other post. He should have whatever # you want and for a better price.

YYZRC

I ended up ordering the SL28-40 from my marina for about $25 each. Really excited about this mod - I hope my little Yammy will fit!

YYZRC

I completed this mod on my 330.  I mounted the lower ball mount about 1/4" above the bottom edge of the locker cut-out and I'm very happy with the outcome.  Thanks LaRea!

YYZRC

One of my gas springs failed. I learned that I installed them upside down and that the seals don’t get lubricated properly when installed with the shaft facing up as shown in my pic above. 

I believe Rinker installed the gas springs upside down originally as well. 

Spyderweb

@YYZRC was the 30# strong enough?

YYZRC

I found 40 pounders eventually. I don’t think 30 would be enough. 

oscar1

Great job

Spyderweb

@YYZRC is this what I want for the 330?
https://www.amazon.com/Spring-extended-length-compressed-Pressure/dp/B019MBDYK0

YYZRC

Yep those are the ones!

Spyderweb

Thanks.  Just ordered them.

LaRea

@YYZRC thanks for this interesting find.  The webby-net seems confused about this issue, but I see more references with the cylinder on the top than the bottom.  I'll switch mine.

YYZRC

Just to add, this is a top ten must do modification - for under $100, it is a game-changer. 

Spyderweb

@YYZRC how critical is that placement of the bottom ball mount.  If you’re off 1\2 inch it just won’t open to it’s full capabilities, OR, you just won’t be able to shut the door?

Just got back from boat today and struts were on doorstep.  Plan to install next trip up.

YYZRC

I’m not sure. I never climbed into the locker to see how close to fully compressed the strut is. I think +/- 1” would be fine. 

Spyderweb

Installed the longer gas springs in the transom locker door this weekend.  What an improvement!  I'm 6'2" and the extra height is so much better for me.  Agree with @YYRC, "a game changer".  Easy and cheap for a boat mod.  Thanks LaRea and YYRC. 

BEFORE


AFTER