Most Class A Motorhomes have shocks on their storage hatches. It makes opening and closing hatches so much easier, stops the issues with those bird beak clips. If you have an RV, you know what I am talking about, the wind picks up, the hatch slams shut. Worse, if you are underneath the hatch and the wind picks up or you lift up too fast it's a recipe for a bump on the head. Well, no more with this modification, that's in the past.
I have seen RV Hatchkits advertised which are easy retrofits to hatches without factory shocks. Install easy and quickly, but they aren't cheap. Most kits I have seen will set you back over a hundred bucks per hatch by the time it shows up at your door. Great company I found called Hatchlift if you aren't keen on building your own.
http://www.hatchlift.com/Default.aspx
Using the hatchlift as inspiration, I searched the Internet for any type of do-it-yourself examples. Not surprising I didn't find much to use as an example. Saw a few videos on replacing existing motorhome hatch shocks which are failing, and one site that had some advice on a home made setup.
So after a couple weeks of searching, I started a list of things I would need.
<strong>SUPPLIES</strong>
20" 30lb 10mm gas shock. *1 per side.
10mm ball gas brackets. *90 degree brackets 2 per side.
Simpson Tie Plates. *1 1/2 per side.
3/16 pop rivets. 5 per side.
1/2" length 1/4" hex head screws. 10 upper, 2 lower per side.
Tube of PL premium construction adhesive.
Gas shocks. For the size of Hatch doors I have, one per side is required. Based on research, 30lb 20" long 10mm ball gas shocks fit my needs. Arguably they are slightly stronger than needed, but in time they will lose some of their strength and balance out.
I ended up buying 6 columbia shocks on eBay. Great deal, worked out to about 12 dollars each with shipping. Seller :
http://myworld.ebay.ca/strut-your-stuff-here/
Next I looked for the 10mm brackets. I determined I would need 90 degree brackets, 2 per side so a total of 4 per hatch. Some installs the bottom bracket might be flat, just depends on how your hatch is installed. For a cougar 5th wheel, this application works. I was going to order these on eBay too, but ended up finding them at princess auto which is a Canadian surplus store. They were about twice the price of eBay, 5 bucks each but sometimes when it's right in front of you just buy it. Each package had the bracket and an extra threaded end. No good for this project but perhaps future considerations.
Simpson Tie Plates, 4"x7" bought these at home depot. The hatch is not strong enough to screw the bracket into on it's own. The construction is a thin piece of aluminum sheeting, styrofoam and fiberglass outer shell. So tie plates seemed like a good idea because they are strong, affordable and have holes pre drilled. It will help distribute the pressure and make it feel more secure.
<strong>INSTALLATION</strong>
First step was to take the 90 degree brackets and pop rivet them into the Simpson tie plate. At first I was going to use the entire Simpsons plate all 4"x7". After a few different prototypes i did not like, I decided to cut a plate down the middle. Still strong surface to mount to the hatch, I was able center the bracket and drill one extra hole for three pop rivets. I installed the pop rivets with the "blind side" face down. I hammered the blind side flat so it would sit flush to the hatch. I could have done the reverse but i wanted to make the surface showing presentable.
Next step was to determine the right installation angle. Using some advice found on the net, I determined the angle of opening should be 103-105 degrees. That would allow hatch to open and close properly while achieving a high enough clearance. The math calculation meant the center of the ball mount on the hatch needed to be 5 3/4" from the top edge of the hatch. So after measuring, I determined the correct spot for attaching the plate and ball gas shock bracket.
After tracing the outline of the plate on the hatch, I applied a liberal portion of PL Premium to the back of the tie plate. After pressing the plate back into place, I used (10) 1/2" screws to secure the plate and allow the adhesive to bond. I then left it overnight to cure.
Next day I was ready to install the lower bracket. With my 5th wheel, I needed to make shims so the bracket would be flush with the hatch opening. I used two pieces of the Simpsons tie plate, worked out to exact thickness required. I needed 1/2" overhang so the shock wouldn't touch the side of the hatch frame. I ended up using two pop rivets into the shims to make this work.
Once I was ready to install, I used a smaller protractor to double check 105 degree angle from the inside hatch edge. I used a broom handle and a block of wood to hold the hatch open to that angle. I attached the gas shock to the top bracket and lined up where the bottom bracket needed to go. After marking the spot, I then applied adhesive to the back of the plate and pressed it in place. Next I had two 1/4" hex head 1" long screws to attach the bottom plate into a metal stud next to the hatch.
Same steps repeated for other side. So last step was to install the gas shocks piston rod side down. I then carefully closed the hatch watching both sides making sure brackets were holding and I had truly got the correct angle. Spot on perfect, door closed and stayed closed without latching or locking. Opening up was smooth and performed as expected. The door is a slight bit stiff to close, the (2) 30 pound shocks are strong. Perhaps could have considered ones with less pressure, however its not that bad and shocks lose strength over time. I think better that then shocks which are borderline weak and will get weaker.
All and all very happy with this modification. *Worked out to around 35 bucks per hatch, and should be a welcome addition for all loading and unloading!