One thing for sure, the OMW design of the receiver assembly is dialed in so well that it would really take an off-the-wall Casita to make installation difficult. Other than that, the DIYer just needs to take care in marking and drilling the holes as after alignment, that's what takes the most time and makes or breaks the installation.
My 2005 Casita frame was very easy to drill. OMW provides excellent installation instructions (http://perfectcasita...h-receiver.html) and the installation kit even includes a silver Sharpie for marking the holes to drill. OMW really thought of everything! The instructions can be downloaded and printed for offline review.
Received the hitch mid afternoon only a few days after placing the order even with an ice storm plaguing the Dallas area. Was anxious to get this project going. After repeatedly reviewing ddaytony's excellent pictorial on Flicker over the past year (http://www.flickr.co...57631977515723/), had installed this thing so many times in my mind that it was going to be a piece of cake.
After getting it out of the box and inventorying all the parts, installed the “S” bracket. This aids in aligning and holding the receiver in place over the bumper for a self install. Like having a 3rd hand. A simple but brilliant feature. The only thing to watch for here is to use a hand torqued Phillips to install the bracket screws (already loosely installed on the hitch). If you use a power driver (with a clutch), set the clutch on a low setting and work up. Otherwise you are sure to strip the head on the 1st screw installed. These screws are soft but good enough for the purpose the “S” bracket serves. Just giving a “heads up”.
Sliding the floor jack under the rig with the hitch perched and balanced on it went fine. My “floor” out here is the AZ high desert landscape. Some cardboard provided an adequate rolling surface for maneuvering the jack. Up the hitch went toward the frame rails and then stalled! The mounting tabs were too wide fore and aft and couldn't get the assembly to go between the frame rails. The wind was blowing and decided to stop for the day. The German in me should have taken care of the fit issue right away, but decided to email OMW before proceeding.
Jim at OMW answered my email right away (after work hours his time) and in 5 words, described the German method for aligning the tabs. Manufacturing variations in Casitas makes each one different enough that the DIYer could encounter any one of 3 scenarios: applying the German method, having to add spacers or it could slip right in just like ddaytony's!
Whacking the mounting tabs inward did it. A wood block and a 2lb short handle sledge makes it easy to control the force applied and protects that beautiful powder coat. The tabs are the only load bearing contact surface with the trailer's frame yet very easy to adjust. The pieces of particle board used in shipping protected the tabs on the ground while striking a block of wood on the tabs from the top, then inverted it to get the other 2.
With the tabs now inside the frame and the “S” hook in place over the bumper, time to install the spacer templates. These templates ensure that the mounting tabs are reasonably positioned over the Casita's “C” channel frame for drilling.
In his email, Jim also described a method to “eyeball” alignment of the receiver to the outside of the bumper. I might not have thought to do this. But since he mentioned it, this can slightly change the position of the mounting tabs to the spacer templates. I clamped a 4' level to the protruding receiver and used a combination square as a depth gauge.
If one wants greater precision in getting the tabs better aligned with the spacer templates AND wants virtually perfect alignment with the bumper, there is enough flex in the hitch assembly that a bottle jack helps move corners enough to clamp them as needed while observing alignment with the bumper. Given the variance in the manufacturing process, something to consider if somebody notices a difference that bothers them. Aligning to the bumper makes it look good if you mount cargo platforms, etc.
The photo below shows the use of the 4' level & combination square. You can also see the cardboard which not only allowed the jack to roll easily over dirt, but also provided a bearing surface for side to side adjustments without having to struggle with the jack.
Clamping the level was really helpful. I was working with a 10 mph wind that would gust higher and kept moving the level. Tapping/tightening the moderately clamped corners of the hitch and finessing the bottle jack quickly dialed it right in! The photo was taken before the bottle jack was applied. The alignment with the spacer templates and the position of the S hook changed slightly, but it is otherwise perfectly aligned. Am all set for drilling. Now if there were only a way to easily drill perfectly centered holes!
The frame was extraordinarily easy to drill. The German in me didn't want to remove the hitch assembly to drill after getting it aligned and marking the holes. Thankfully, didn't have to. I was able to snake my wingspan over the hitch cross members, around the bumper and maneuver the rear stabilizer jacks to get a fairly large 18v Ryobi drill (keyless chuck!) even into the confined aft corners.
I used a 2 /12" deck screw to mark the hole centers because I didn't have a punch. Seems like you can't buy just a carbide tipped center punch anymore. Deck screws are easy to hold, sufficiently tempered/hardened and one screw was tough enough to mark all 8 holes and then some. The starting drill bit a 1/8" hex shank (from Harbor Freight) did not walk at all. From there, I stepped up to a 1/4” round shank and then to 25/64” from my drill index. The latter is a step above a 3/8” and the biggest bit that would fit the Ryobi keyless chuck but still a bit below the 7/16” size needed for the bolts.
All of these holes were drilled from the inside (mounting tab side) so I could observe the centering with the mounting tab holes. I finished the 7/16” with a cone shaped hex shank step bit (also from Harbor Freight) from the outside, making the hole just big enough to accept the bolts. The step bit was also helpful to get one hole back on center after marking and drilling it slightly off center. (That's what can happen if you get too much confidence and try to move quickly.) Could use it as a reamer that was very easy to guide.
The only place drilling struggled was just before the round shank bits broke all the way through. Round shank bits will inevitably spin in a keyless chuck here. Backing the drill out, letting it spin up and ever so lightly re-applying pressure takes care of that. Making sure the battery is fully charged is a good pick, too.
Started drilling the easiest mounting points first and snugging the bolts to anchor the assembly while moving the bottle jack to another corner as needed for spacer template alignment while maintaining horizontal alignment with the bumper. One hole at at time and suddenly...it's in!
An expanded summary on the tools/gear that helped:
a short handled 2lb sledge. Takes very little movement to get the job done either marking holes in the tight working space under the trailer or for better control of realigning the tabs.
a block of wood to strike if tabs need to be realigned. Use wood from shipping contents to protect bottom tabs.
another block of wood to protect the powder coat when perching and balancing the hitch assembly on the floor jack
deck screw to use as a center punch
a cone shaped step drill with hex shank (Harbor Freight). It doesn't slip in the the keyless drill chuck and the bit won't slip inside the hex shank, either (very impressive for HF price point!).
a pillow or something for neck support while on your back. You'll be there a while!
4' level, clamp + combination square to align receiver with the bumper
hydraulic bottle jack if you insist on near perfection
I was considering trying a much smaller Harbor Freight high speed pneumatic drill if my Ryobi with its battery back was going to be too big. The Ryobi worked, though. I simply did not want to drop the hitch to drill !
I don't know if a torque spec would be useful for the mounting bolts. Normally, when working with a split lock washer, I make sure the washer is flat and everything is snugly torqued. I also tighten the bolt while holding the nut. Prevents distorting the washer. I'll check them again a few times just to make sure they don't loosen up.
Jim expressed an interest in incorporating some of my lessons learned from this installation. It's seldom that you run across that kind of open-mindedness nowadays. I don't know how much "how-to" would be appropriate to include in instructions without making them unwieldy. Many taking this on would probably know what to do anyway. The focus would be on the owner that might be sitting on the fence on whether or not to tackle this job. OMW's mission is to make it as easy as possible on the DIYer.
This installation was not really difficult. Being careful and methodical took a good part of the day. One thing that comes to mind is if scissor jacks had been welded in place of the stock telescoping stabilizer jacks could make getting around in the tight space more difficult. As mentioned before, DIYer just needs to take time and care in marking and drilling, as after alignment, that's what makes or breaks the installation. Use sharp bits!
After getting the bikes mounted* and having someone follow to observe motion, it became more clear the value a shock kit could be. Of course, we Casita owners already know the value of shocks, don't we? https://www.youtube....be_gdata_player
* I am using a Thule Helium 970XT/971XT that I bought because of its light weight, served reasonably as a bike stand and it's collapsible when not in use. It also allows for a solid and lockable connection to a 1 1/2" - 2" receiver to eliminate wobble and deter the opportunistic thief. It has integrated locking cables to secure the bikes. As this bears the weight of the bikes on their frames, it is NOT recommended for carrying bikes on the rear of a trailer. It was ~$400 and already had it. I've managed to eliminate/damp its movement enough to give it a try.
Edited by garyinpreskitt, 15 March 2014 - 03:47 PM.