Replace rear stabilizer with true scissor leveling jack

tybladesmith

@Sharon_is_SAM, maybe I am the first to do the cross beam and beefier "C" jacks. About the stickers, BAL sent me more of the same stickers as I am using their "C" Jacks. I will probably leave them on. Thanks for asking.

BrianZ

Very interesting @tybladesmith, but I thought that type of BAL stabilizer was not made for lifting, only for supporting an already jacked up trailer.  My question is, in other words, is it made for jacking up heavy loads or just static support of them?  One issue that @Dalehelman had pointed out is that the footplate moves or slides laterally (or else the trailer would) rather than going straight up & down like a scissor jack, and cause binding.
So, is this one different in that regard?

tybladesmith

@BrianZ, BAL is calling it a stabilizer/jack. Because of the 4000lb. rating I am assuming it can handle more than their 1000lb. stabilizer. I am also assuming a rear jack is only lifting 800 lbs. with a T@B 320. Because they are made for heavier travel trailers I am also assuming they have to say the same thing to bigger camper owners- don't lift. This jack design does not move the foot laterally as the jack leg moves toward vertical. Good geometry! The top of the leg moves outboard as the foot drops in the vertical plane. The jack foot swivels relative to the jack leg.

BAL states DO NOT attempt to use this stabilizing Jack to lift excessive weight or tires off the ground. Only use stock handle supplied. ….We should all throw our lifting drills away? I don't mean to be flippant but common sense is required to operate a T@B safely and successfully. 

I am not an engineer! Have I made bad assumptions? I don't want to lead anyone a stray.

jkjenn

I was under the impression that stabilizer and leveling Jack's were designed differently.

plicato

I had the same question thinking the stabilizers could be used as jacks.  But then Dale Helman pointed out why the stabilizers are not suitable for this.  Please refer to:

https://tab-rv.vanillacommunity.com/discussion/comment/97959#Comment_97959

tybladesmith

With due respect to @Dalehelman I followed his recommendation for a 30" scissor jack, mine rated for 6500 lb. I was totally uncomfortable with that jack on a Boondock. The jack flexed and wobbled side to side on a moderately side sloped site. I took them off as soon as I got home after only one outing. The BAL 'C" type Stabilizer/Jack is much more robust than the 6500 lb. scissor jack in my opinion.
 I did not find any BAL literature listing dynamic load rating, only static -even for scissor jacks.
 I will continue to test it in the real world. I will continue to carry stacking leveling blocks.
The "C" type is in a different class than a light trailer stabilizer. 


http://norcoind.com/bal/products/consumer/stabilizing_products/c-jack.shtml
http://norcoind.com/bal/downloads/manuals/C-Jack.pdf

BrianZ

@tybladesmith, although this is not a spec sheet, it appears to indicate in writing the intended purpose of leveling scissor jacks at the bottom left of your second document..

... whereas the stabilizers are only intended to to provide limited "fine leveling". 

I guess there is an argument to be made for extending the capacity of how much weigh such fine leveling can handle by using an oversized stabilizer made for a much larger RV on a lighter weight T@B.  But it's still the same design intended for a different purpose, and how much is too much would be anybody's guess.

As far as the side-to-side flexing in the scissor jacks, I can see how that might be a bit of an issue if they were both installed sideways; but, most jack mods have been done with them mounted at an angle to both the trailer & to each other, which minimizes  that motion & adds stability.

I'm curious though... Can you easily do the amount of lifting you want using only the hand crank and without excessive effort at torqueing it?
(auto-correct tried to change that to "torturing"  )

Dalehelman

Please feel free to count me out of this discussion. My feelings will not be hurt in any way. For the type of camping we do my  solution has been more than  satisfactory over the last four years. To my knowledge know one using if it has any issues to date. I have personally installed over a dozen. I have know idea how many have been done by DIYs. I also must say it is not designed or Intended or recommended for extreme situations.

Homebodyatheart

@Jilong, when all else fails call NuCamp when they are open and ask the folk who know your trailer best about the infrastructure. Good luck!

tybladesmith

@BrianZ BAL C-Jack brochure states; Steadiness of a stabilizing jack with strength of a leveling jack.
Yes, the jack easily lifts a wheel off the ground with little more effort than the OEM stabilizer.
@plicato to answer your concern the C-Jack does not move in an arc like the OEM stabilizer and does not cause binding. The jack toggle links are designed to cause the foot plate to travel in the vertical plane.

Sharon_is_SAM

What is fine leveling?

BrianZ

It looks like the 4000 lb strength they are referring to is labeled in fine print as "static load capacity", but never uses the words "lift" or "lifting".  BAL seems to use that "fine leveling" term in all their stabilizer literature, as in the one shown above, or the one that came with our T@B below...

While it's not defined, I would guess they are referring to small adjustments beyond the point when the foot contacts the ground, such that the trailer body is raised slightly, but most of the trailer weight is still on the wheels & axle.  I wonder if the C-jacks come with the same safety warning as shown above for the stock ones.

It does appear that they have moved the attachment point of the secondary arm lower on the main support arm of this jack, such that the foot could move vertically.
Good idea to run it by NüCamp if anyone seeks a more authoritative opinion.

tybladesmith

@Sharon_is_SAM, I called BAL and talked with John a sales manager. He clarified fine leveling. Lifting maybe 1" but not lifting a tire off the ground. I will not advocate using "C" jacks for lifting, regardless of static load rating. Follow NuCamp instructions! My Bad!!

Sharon_is_SAM

So fine leveling can be defined as actually adjusting the Tab as measured by a level device, but not lifting a tire off the ground.  Makes sense.  Not designed for suspension, only for support.

BrianZ

@tybladesmith, thanks for sharing that clarification from BAL.  Sorry if you didn't hear what you wanted to hear from them, but I  wish they would just stop calling them "jacks" and only refer to them as "stabilizers", in order to avoid being misleading.
I do like your design though, if true scissor jacks could be used at an angle for stability and still give adequate clearance.

ScottG

tybladesmith said:

@Sharon_is_SAM, I called BAL and talked with John a sales manager. He clarified fine leveling. Lifting maybe 1" but not lifting a tire off the ground. I will not advocate using "C" jacks for lifting, regardless of static load rating. Follow NuCamp instructions! My Bad!!

This was my interpretation, and something I do routinely. Thanks for the confirmation!