Replace rear stabilizer with true scissor leveling jack

plicato

After reading the discussions on mounting scissor jacks in place of the rear stabilizers, I decided to install them on my 2018 T@B 320 S.  I planned to fabricate Dale Helman’s mounting adapter plate myself.   I then stumbled upon BrianZ’s article on how to extend and stabilize the mount.  I thought that might be the best option.

My brother-in-law has a scrap yard here In town.  My nephew helped me assemble all the steel pieces and we intended to fabricate the Helman plate with the BrianZ stabilizer triangle. 

After crawling under the trailer and discussing various options, my nephew proposed a different design, using 1x2" rectangular steel tubing to mount over the stabilizer bolts, thereby providing a separate surface to mount the scissor jack.  I wanted to tie in the third bolt, so we decided to weld a section to form a T.  The T would fit nicely and symmetrically over the three stabilizer bolts within the trailer frame angle iron “track” and allow the scissor jack to be attached securely.  And it’s 100% bolt-on.

My nephew did the TIG welding, and we ground the welds flat so that the brackets would rest flush against the bottom of the trailer.  After drilling the pilot holes, we double checked the fit on the trailer.  Here we discovered that we messed up on one of the hole measurements and had to drill a new hole, after which everything fit perfectly.  Then we drilled the larger holes, which serve to allow access to the nuts that fastened the bracket to the bolts on the trailer, wide enough to accommodate a thin-walled ¾” socket.   A lap pad on a grinder was used to get all the rust off.  Finally, the brackets were thoroughly cleaned with acetone and then painted with gloss black Rustoleum.

I really like Dale Helman’s plate and it appears to be a reliable and proven design that is relatively easy to fabricate and install.  BrianZ’s design adds some extra stability and may be worth the effort if you have the skills and resources.

Our design is likely overkill, but it is extremely solid and stable.  I can easily lift both tires off the ground with little effort (although I do use a 20V cordless drill to do all the work!).  The jacks are angled inward slightly which adds to the overall stability.  One downside is that the jacks sit 1" lower than either Dale or Brian's implementation.  But there is still plenty of clearance when the jacks are stowed and I don't believe this will be a problem.

I still use the original front stabilizers as well.  I just returned from our first camping trip with the scissor jacks installed.  It was really quick and easy to level the trailer.  Mission accomplished!

If you decide to follow this approach, I advise you to make your own measurements!  (Mine are not guaranteed.)  Measure twice, cut once!

Michigan_Mike

Nice work and write up and thanks for sharing as this will help others out down the road.  

Well done!  

ScottG

Looks good. If possible, a photo from underneath showing exactly how these attach would be helpful for understanding how it all fits together.

BrianZ

Beautiful solution, @plicato!  I believe you have found the best design possible (for jacking up to level or support trailer weight off the wheels), and the only one that centers all of the upward forces directly under the trailer frame, which is ideal.
As you stated, the only real negative is lowering the jacks by an inch, which may be the most minimal tradeoff of any design I've seen yet, considering it offers greatest possible strength with the lowest amount of risk.  The others may offer closer access to the jacks from the side, but not by a lot.

I don't think you addressed or photographed this, but didn't you still need to cut a slot into the top surface of the cross member for the short vertical part of the trailer frame to fit into?  Would be interesting to see a photo of the other side showing that corner of your bracket where the corner of the trailer frame is close to the bolt.

Great work & great 3D thinking on the part of your nephew!  Not sure I would consider replacing mine at this point, but if I was just starting, I'd surely choose your design.

plicato

There is no need for the notch since the trailer angle iron fits tightly into the corner of the T. 

Thanks for the comments and feedback.  I’ll take a better closeup photo so that it’s clear how it is mounted.

Dalehelman

When the original factory stabilizers are used to support the weight of the trailer for wheel or tire service. All of the weight is on the two rear studs of the stabilizer. There is actually negative weight on the third bolt. My goal was to provide simple inexpensive effective solution that anyone with some basic hand tools could do themselves.

ScottG

I agree with Dale regarding the load physics of the original stabilizers. Regardless, the load placed on those points will be much greater with two humans bouncing around in the trailer then when used for wheel or tire service.

That said, Dale has used his mod without incident for a few seasons now. Some would prefer the security of a more robust mounting. I think it's a neat mod either way, but personally find it no big deal to pull the camper up on a 2x8 if needed. To each their own!  :-)

BrianZ

@plicato, your driver/passenger side labels appear to be reversed in the first photo.  At least on our T@B, the rear mounting bolt closest to the vertical side of frame is at the inside edge, unless you didn't mount directly against that vertical side of frame, or I'm having a spell of dyslexia. 🤪

In other words, as I look at your first photo, if this is the view that I would see laying on my back with my head under the rear of the trailer & feet sticking out to the rear (which I think is the case), then the driver's side would be to my right.

tybladesmith

@plicato, I have also been playing with jacks for my boondock. I found the 30" jacks a little wobbly and was concerned with the back bolts anchored in 2x4. I got a 1-1/2" x 4" tube and cut relief grooves to allow the frame flange to pass into the tube allowing the tube to place all the load directly on the frame, well in front of the back bolt locations.

Too much overhang compared to departure angle

Jack beam fit-up


Jack beam loaded - note gap to floor at finger

note: groove for frame flange

Departure angle now. I tried the jacks angled to beam centerline but didn't like it.


Jack hex drive easily accessible from side

Ultra-Fab 6500# jacks
https://www.amazon.com/gp/product/B0050EFRIG/ref=oh_aui_detailpage_o07_s01?ie=UTF8&psc=1 

Sharon_is_SAM

@tybladesmith, and yet another version!  I like the hex drive at the side.  Everytime I lean over to find them at the rear, I think my DH will need to pick me up off the ground😀

I think the next challenge is to come up with a remote control to lower the jacks!  

ScottG

tybladesmith said:

...place all the load directly on the frame...

Regardless of the design particulars, this would be the key consideration if I were going to attempt this modification with the intent of raising the trailer off the ground and supporting not only the weight of the trailer itself but also the additional dynamic loads created by the occupants.

The physics here aren't much different from building a house. Point loads should be adequately supported and transferred directly to a structure capable of supporting them.

The original stabilizers incorporate a steel top bracket that fits almost entirely in the groove of the trailer frame extensions. That bracket effectively transfers the load to the frame--the two back bolts serve only to hold the bracket in place along the frame. @plicato's design comes closest to duplicating the load distribution of the original stabilizers.

All of this assumes that the frame extensions themselves are capable of supporting the increased load. I suspect they are. Whether the wooden elements of the camper body are capable of doing the same is anybody's guess. Connecting the jacks directly to the steel frame eliminates that uncertainty. 

BrianZ

Beefy, beefier, beefiest. 😉

Jilong

The many different ways people have done this mod in this thread have given me the courage to try my hand at doing this to my new T@B 400. I haven't yet seen any posts from any 400 owners on replacing their rear stabilizers, but I'll investigate on mine.

BrianZ

@tybladesmith, I'm wondering if you ever considered making your box beam about 8" longer on both ends and mounting the Jack's in that area, more lateral for increased stability.  That was an idea I considered, but hadn't though of using a box beam at that point.
By angling them a bit towards the back corner it looks like you could still stay inside your departure line.  Just a thought I had, as your mounting points look much closer to the centerline than any others.

ScottG

Jilong said:

The many different ways people have done this mod in this thread have given me the courage to try my hand at doing this to my new T@B 400. I haven't yet seen any posts from any 400 owners on replacing their rear stabilizers, but I'll investigate on mine.

The 400 is a heavier trailer, and its layout suggests the weight load of the occupants will be carried further back than on the 320.

I don't know exactly how the 400's stabilizers are attached, but if you use sturdy enough jacks--and the frame is robust enough--there's no obvious reason it couldn't work in the same way.

I do suggest you re-read my previous post and give some thought to where your load bearing points are, are how those loads are transferred to and distributed along the frame. Good luck and let us know what you come up with!

jgram2

And I wonder if the 400 uses the same wooden cross member which appear to have caused some concern, as the 320’s

ScottG

I would consider the wooden cross member to be part of the camper body, and I suspect the 400 and 320 are constructed similarly.

Either way, I would not be comfortable using parts of the camper body to support the weight of the trailer, no matter how robust they may appear. The camper body should be entirely supported by the trailer frame, not vice versa.

Sawtooth

The holy grail would be to add an independently controlled air bag suspension to the trailer.  Then you could level with the suspension system at the axle per factory recommendations.  Plus you could raise the T@B up for off-road clearance and then drop it back down at the campsite for the appropriate height for you CS kitchen.  

@Dalehelman , I'll take a set when you get it all worked out.

Dalehelman

Just spent three days on the  Oregon coast at a somewhat uneven state park camp site. Our passenger side tire was 2” off the ground. The trailer  was very stable no sense of instability. Even with four adults inside at times. This is real world experience not theory. After almost 4 years of usage there are know signs of problems. All doors windows cabinets and interior structures are still tight and in perfect alignment. There is really know end the ability to over engineer an application. My goal was functionality with simplicity.

ScottG

Fair enough. I'm not trying to start an argument or knock down anyone's design. I've acknowledged multiple times that Dale's original design has withstood extended real world use.

My buddy used to drive by a house built by an owner with (apparently) limited knowledge of the engineering principles that are fashionable to disparage. The house had a cathedral ceiling but nothing holding the outside walls together. It stood for a few years until--following an unusually large snowfall--it didn't.

Yes, things are over engineered. That's because they are built not for the normal conditions encountered 90, or 99, or even 99.9% of the time. They are built for those few unusual circumstances that can really ruin your day.

Since a broken camper creates little threat to public or personal safety, owners can decide for themselves the level of risk they are willing to accept. However, as a conscientious contributor to this forum, I would be remiss if I didn't offer those owners as much information as possible.

ericnliz

@ScottG, I also have the "Helman Special" installed on my T@B ( I even have @Dalehelman DNA from the experience 'cause the WolfT@B bit him!), and couldn't be happier. Leveling by myself is a breeze now, and the stability you feel inside is far superior to the original stabilizers. No more fussing with levelers, or jacks to do maintenance on bearings, or tires. Thumbs up to those that have improvised, and re-enforced the original idea, but my opinion is the old "K.I.S.S." method does the job quite well, & I, for one, am very happy with the end result. Just my most humble opinion... Have a nice day!

Jilong

Having examined the underside of my T@B 400, I can say that the rear stabilizers are bolted to the trailer frame at the front end. However, at the rear end, they are screwed into a wood beam with what looks like a thin piece of aluminum reinforcement over the wood. I'm pretty sure that the wood beam is just part of the camper body. I can reach one set of rear bolts directly from the drain access panel.

This looks remarkably sketchy to me. They aren't kidding when they say the rear stabilizers on the 400 are just meant for stabilizing and not for leveling. Since the rear stabilizers are directly under the queen bed, it seems like there is potentially a lot of stress on those rear stabilizers depending on the amount of force applied from above.

I'm definitely going to replace those stabilizers with jacks that only leverage the frame.

plicato

Hi everyone.  I personally didn’t mean to offend anyone or say that one implementation is better than another.  I said right up front that I had intended to implement Dale Helman’s proven and easy to make and install adapter plate.  Only when other options and resources presented themselves did we decide to pursue a brute force option.

BrianZ, you are correct, my original picture is backwards.  Please excuse my dyslexia.  Here is a corrected drawing:


As I mentioned previously, we didn't have to cut a notch to accommodate the trailer frame.  It fits snugly into the corner of the T bracket.  Here is a picture of the driver side bracket. It's a bit hard to see with the scissors jack in the way, but the T is just on the outside of the frame angle iron.  Hope this helps!

-- Paul Licato

ScottG

@Jilong, can you provide a photo showing the stabilizer mounting you describe. It sounds very similar to how the 320 is configured. However, with the 320 the rear stabilizer is actually in contact with the frame over almost all of its length.

On a related note, the front stabilizers on the 320 appear to be simply bolted to the camper floor. I consider this less of a concern however, as the tongue jack carries most of the load, and you would never use the front stabilizers for raising the trailer (as for changing a tire).

ericnliz

@plicato, I really don't believe you offended anyone, so, please don't take it that way. The way folks do mods THEIR way is both unique, and very educational. We are all individuals with different wants, needs, and ways of looking at, & improvising things. That is one of the things I enjoy about this forum is the diversity & different insights on various problems, solutions & mods. I believe it boils down to what makes YOU comfortable , or happy in YOUR situation, not someone else's. I found your mod to be an excellent adaptation to an original idea. I'm also quite sure we haven't seen the last of the full spectrum for this idea as folks adapt this to the 400 models as well. Keep up the good work, & thanks for sharing your ideas & mods, they are inspiring to not only myself, but others as well.
Eric

dinzzy

I have the clam shell T@B and the scissor jacks stick out too far and hit my shines when at the kitchen.  Dale is investigating an option that I might be able t use.  This is a great way to lift and stabilize the trailer!

tybladesmith

@BrianZ, I did consider keeping the jacks to the outside of the frame and parallel to it. With the Boondock, the 30" scissor jack is 12" longer than a 24" jack. During that mockup, the front of the jack screw was approaching the rear side of the tire while trying to reduce the departure angle. That is why I ended up orienting the jacks perpendicular to the frame



This was the mockup of the jack angled to the rear. I found little benefit during the brief evaluation. My assumption is that lateral stability will be maintained as long as one tire stays on the ground. 

This continues to be a work in progress. Thank you all for your great input.

I totally agree with Dalehelman that functionality with simplicity is the goal. 
The plan was to be able to both stabilize the camper quickly with out blocking or BAL leveler and jack the camper for a tire change.
However with the Boondock, it starts out with 6" more lever arm than the 24" stabilizer, before the tire leaves the ground, allowing the jack to be less stable, hence this project for Boondockers.

BrianZ

Thanks, @tybladesmith, for explaining.  I forgot you need to deal with the longer Jack's.  Makes sense.  Also agree with the "as long as one tire stays on the ground".  I still feel more secure with two tires on the ground anyway.  We just got back yesterday from this site where we would have had one tire off the ground due to a downhill driveway..

Since we had some 2x8 blocks with us, we stuck one under the downhill wheel on the door side, which is still easy to do with a jack. We could also chock both wheels that way.  We used the new 8" tongue wheels for the first time to rotate the T@B by the handles to reposition going across the driveway so the door would be facing into the campsite & forest.  It worked great.  Not sure if we could have gotten safely leveled if we had the tongue uphill, while trying to get two wheels off the ground.  In any case, using the now built-in jacks & tongue wheels got us where we wanted to be, perpendicular to the car in the driveway & with minimal effort.

Edit:
This shot while still setting up shows the situation better..

When it came time to leave, I realized I hadn't considered that I would need to roll that downhill wheel back uphill to get repositioned for hitching. I wondered if I'd have the strength, but rolling it down off of the two 2x8 blocks got it started with some extra momentum, so it was no problem (with some help from my wife who was ready to chock the wheel before it had a chance to roll back).

tybladesmith

Thanks @BrianZ, great to hear how you use the jacks and tongue wheels to help with camper placement. Nice camp setup!

tybladesmith

@plicato I apologize for hijacking your post for scissor jacks. I too started out with @Dalehelman brackets and scissor jacks but was not satisfied with the result for a 320 S Boondock. I found it less stable in steeper terrain. 

Combining ideas from @Dalehelman, @plicato, and @BrianZ a new approach came to mind.

Second attempt at making a rear jacking/stabilizer beam for a NuCamp T@B 320 Boondock.

The plan was to be able to both stabilize the camper quickly without blocking or BAL leveler and jack the camper up for a tire change. NuCamp and BAL state the original equipment stabilizer jacks can’t lift a tire off the ground, only the tongue jack

I wanted all the weight of the camper to be carried by the frame forward of the two rear stabilizer mounting bolts which go into a wooden 2x4, not the steel frame. I also wanted the jacks to be as wide spread as possible for stability.

However with the Boondock, using 30” scissor jacks it starts out with 6" more lever arm than the 19” stabilizer, before the tire leaves the ground, allowing the jack to be less stable, hence this project for Boondockers.

For this attempt a set of BAL 25” “C” jacks like the original equipment stabilizers was chosen, but with a 4000 lb. rating rather than the 1000 lb. rating of the originals.

I fabricated “tees” of 2” by 1/4” flat steel and drilled the three holes to fit the frame. They were temporarily bolted to the rear stabilizer locations. Next the height of the frame flange was measured.

I used a 1-1/2” by 4” 11 gage rectangular tube 70” long. Next the width of the trailer frame and flange was found and was laid out on the beam and slots were sawed into the beam to the depth of the flange. A 1/4” drill bit was used to radius and separate the sawed slots and an angle grinder was used to widen for an easy fit. The purpose of the slots is to allow the beam to rest completely on the frame and carry all the lifting force to the frame steel only.

The beam was trial fitted to the Tee brackets and squared to the frame and then tack welded. Next 1-1/2” by 1/4” angle iron pieces were cut and drilled matching the bolt pattern of the “C” Jacks and tack welded to the beam. 

Note: Shore power was disconnected, batteries isolated, and welder ground was attached to beam away from converter box to reduce likelihood of electrical damage while tack welding. Just to be clear, nothing is welded directly to the trailer frame. This is a slip fit and only original bolt locations were used.

The beam was then removed from the camper and welded complete and prepped for paint. Geo foam was injected into the ends to prevent insects and vermin from easy access inside the beam.

After painting, the beam and jacks were installed and tested. With one wheel lifted off the ground there was no measurable deflection of the beam. The departure angle was checked, and a small improvement was found. The jacks do hang down about 1-1/2” below the bottom of the trailer. The new beam and beefy jacks add about 47 lb. to the weight of the trailer.  

https://www.amazon.com/gp/product/B002P2YTIA/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B004OI21MY/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1


Top view
Side view of angle brackets and Geofoam sprayed into beam end to keep animals out.  Note: Each TEE bracket has relief ground in for frame flange clearance above inboard back bolt hole.

Beam and ”C” Jacks installed

Clearance of beam to drains

Jacks are about 16" wider spread than the original stabilizers.

Departure angle – nothing hanging down

Jacks hang down about 1-1/2” below bottom of trailer. Beam and jacks added 47 lbs. to trailer. Note: BAL provided more of the stickers seen above the jack.

I now need to get out in the real world and test the ease of setup, stability, and also hope to never change a tire in the field.

Dale I know it is overkill but 1/4" stock is what I had on hand. I have also removed the Yakima basket and tire from the rear of the trailer. I haven't measured or adjusted tongue weight yet.

BAL could easily add an engineered HSLA beam for an OEM factory option to NuCamp if there is enough interest.

Sharon_is_SAM

@tybladesmith, are you the first boondock owner to do this?  Do you need to remove the BAL stickers?