Tandem Axles - Shocks or Equalizers?

[V'sGlassSleeper]

My rig: 1988 Bigfoot B19 tandem axle. Dry weight on manufacturer sticker = 3,240 lb. Likely maximum weight 4,500 lb.

Towing with: Nissan Frontier V6 Nismo 4 x 4 with offroad suspension

My truck has no trouble towing this trailer at all. I recently removed the outrageously heavy Equalizer weight distribution hitch (which was overkill and too heavy for me to deal with) and instead installed two Curtis Sway-Control bars (one on each side). I wanted to upgrade the suspension - either with shocks or new equalizers - because I read posts from others who've installed shocks and said that this improved the handling tremendously.

My main goal is to proactively dampen any bounce or sway when I take the travel trailer on roads that tend to have gusts of wind and when passing 18-wheelers. I have not experienced any issues yet, but notice that my truck really gets buffeted along some stretches when I am not towing, so wanted to be proactive for when I am towing.

To that end, I have read through Brian B-P's thread and Jared L's thread on adding shock absorbers and am trying to decide between adding shocks or adding equalizers and would appreciate input ONLY from those members who actually have first-hand experience with replacing their equalizers and/or shock absorbers.

There are 3 shock kits for retrofitting travel trailers: the Dexter hydraulic shock kit with weld-on brackets (comes in kit ; the Lippert gas shock kit with bolt-on brackets (for 2 3/8" axles); and the Roadmaster (for 2 3/8" and also with kit for 3" axles).

Dexter hydraulic shocks with weld-on brackets (kits for 2 3/8" and 3" axles): https://www.rvupgradestore.com/Dexte...-p/46-3000.htm

Lippert gas shock kit with bolt-on brackets (for 2 3/8" axles): https://www.etrailer.com/Trailer-Sus...SABEgI8zvD_BwE

Roadmaster gas shocks with bolt-on brackets (kits for 2 3/8" and 3" axles).: https://tweetys.com/joy-rider-traile...nch-axles.aspx

There are also replacement equalizers that are supposed to provide similar ride dampening as shocks:

Lippert: https://www.etrailer.com/Trailer-Sus...SABEgK-u_D_BwE

MorRyde: https://www.amazon.com/MORryde-CRE2-...suspension+kit

Of the two dozen trailer parts suppliers/service stores that I spoke with today, only 3 specialize in travel trailer suspensions (most work on industrial/utility trailers). Two of these said that shocks are just a placebo and don't actually do anything and that I would do better to change out just the equalizers and get a "suspension service" to ensure that my nylon bushings, shackles and leaf springs are in good shape.

I don't have money to waste on "placebo" parts. My goal was to do just one upgrade to make the handling even better. If shocks don't do anything, why would several members indicate that adding them greatly improved their ride? Is it true that adding new equalizers would be an even more effective option? Yet another service place said to forget both and replace my straight axles with torsion axles instead. I need to balance effectiveness and cost. Does anyone have experience with these? Thank you!

[cpaharley2008]

What about different tires with softer sidewalls and lower air pressure capability?

[Raspy]

I looked carefully at the Dexter rubber equalizer system (EZ Flex) and the MORyde setup. Don't waste your money thinking either will do what shocks do. It's a different function and neither will do much to change the ride of a travel trailer. The rubber absorbs almost nothing with the relatively soft springs that tandem axle travel trailers have. They are designed to absorb large sudden loads from very stiff springs. There are videos on each one and when watched carefully and when compared to standard equalizers, you'll see that they won't do much, if anything for the typical travel trailer.

Tires that are soft because of lower pressure, will reduce some of the impact that bumps have, but that will create more heat and threaten the tires while on higher speed highways. Tire pressure low enough to make a significant suspension difference is good only at very low speeds. Some folks claim that trailer tires should be inflated to max pressure all the time, but that will make the trailer ride rough all the time, just to help keep the tires cool. Running them at the proper pressure is a better goal and running tires that can take the load at a proper pressure, is very important (that's code for running LT tires and may incite a riot on here).

The Dexter heavy duty suspension kit is a very good addition to tandem axle suspensions because it provides heavy duty shackles and greaseable bushings, that replace the standard nylon bushings that wear out and get very loose. But the EZFlex, for instance, costs about $100. more than the Heavy Duty kit and really does nothing extra. I'm sure that holds for the MORyde setup too.

Shocks will reduce bouncing and tilting from side to side as you drive. They may also help reduce sway and improve braking.

[V'sGlassSleeper]

Thank you, Raspy, for your helpful response and assessment of the options! I also heard from Brian B-P, whom I contacted for his input as well since he had installed shocks on his Boler with good results. I had been leaning toward shocks but several trailer service centers were trying to sell me on the equalizers (they also incorrectly assumed that my Bigfoot's equalizers had nylon bushings when they are all metal and both the spring leafs and equalizers seem in good shape).

I feel reassured that adding the shocks is the best way to go - once I can figure out what size axles I have! I had the drop axles replaced with straight axles when I first bought my Bigfoot and nothing on the work receipt indicates the brand or size of axles. I will crawl under there tomorrow to see if I can find any imprints or labels, but I was just under there a month or so ago when sanding, priming and painting the frame and I don't remember seeing anything labeling the axles. I measured an axle with a seamstress' tape measure today and got exactly 7" circumference; my auto mechanic used a caliper and got 2.5" diameter. I thought axles only come in 2.375" diam., 3" diam. and 3.5" diam, so not sure what to make of my or my mechanic's measurements.

I spoke with at least 24 different trailer parts stores and none of them have individual brackets to create one's own retro shock kit. I did learn that the weld-on Dexter shock kit is only hydraulic, not gas, so that's out. The bolt-on Lippert gas kit is very poorly-rated. So that leaves two potential gas shock retrofit kits that are pricey, but include everything needed and are available for 2.375" diam., 3" diam. and 3.5" diam. axles:

The Roadmaster Comfort Ride: Roadmaster Inc. - Tow Bars, Braking Systems & RV Accessories About $495

The JoyRider Shock Kit: Joy Rider About $450

The JoyRider is owned by a guy named Sonny, who lives here in Arizona. Sonny says that his JoyRider system helps dampen bounce and side-to-side movement because the shocks are installed at a 15 degree angle vertically as well as horizontally from the axle to the frame. Sonny said he would help guide my auto mechanic on the install to make it as easy. My mechanic is very honest, reliable and experienced with all sorts of autos, but has not installed shocks on a travel trailer before - he is willing to do it because he loves a challenge and he knows I have not had good luck with the high-priced RV mechanics I've tried so far.

I do not have the engineering background to determine if what Sonny says about his system has any credibility. Both systems are expensive, but I plan to use my Bigfoot a lot over the next 20+ years and want to travel as far as Canada, so a smoother ride is important to me. Any input about these systems from those of you with enough engineering/suspension knowledge to be able to assess them is much appreciated.


Thank you!

[V'sGlassSleeper]

I just got off the phone with a suspension and alignment shop that was (ironically) recommended by Sonny and they advised me that he had sold his company to Roadmaster and that the kit Sonny was trying to sell me was nothing more than his old inventory and that neither kit was appropriate for a small trailer.

According to that shop, both the Roadmaster and the JoyRider (now both owned by Roadmaster, not Sonny) are meant for much heavier, larger rigs and toyhaulers and would not be appropriate to install on smaller travel trailers. They recommended a "suspension service" to determine if my leaf springs, shackles and bushings need replacing and said that the best product for a smaller trailer like mine would be Sumo Bump Stops installed on the trailer: https://www.supersprings.com/product...r-sumosprings/. They quoted $850 to install these bump stops on both axles. Ouch! That definitely is not in my budget.

There are clearly a number of fiberglass forum members who have found that installing shocks improves their ride, but finding the right shocks for these little travel trailers is proving to be a real challenge. Seems like a great niche for some enterprising mechanical engineer!

At this point, I am going to revisit the Lippert gas shock kit because it is about half the cost of the Roadmaster and JoyRider kits. It had mixed reviews, but if I get it on Amazon and it comes missing some parts (which is what most of the complaints were about), I can return the kits. If the shocks go bad prematurely (which is what some of the other complaints were about), then replacement shocks are $40 each and apparently the brackets are well-made (as long as you get all the pieces in the box). It's a bolt-on kit and at that price, hopefully, it works well enough. I will call their tech support tomorrow to ensure that the shocks are short enough to fit for this application.

To be continued!

[V'sGlassSleeper]

Brian B-P, Thank you again for all your input! Attached are some photos of my suspension and a diagram showing all measurements. I just noticed one measurement I forgot to include - the space from the interior edge of the tire to the exterior edge of the frame is 3.5"

Whew!

So far, I am leaning toward the Lippert retrofit shocks because of the lower cost for the kit and their shocks are easy and relatively inexpensive to replace. I look forward to hearing your thoughts on the subject.

I thought the Casitas had a different suspension, but could contact them as well if you think that might be a better option that the Lippert kit. I am hoping to gather materials together within the next week so that my mechanic can get started on the project. Planning to have him install new brake pads at the same time. Mine looked fine, but they are old, so I want to be proactive about that.

[V'sGlassSleeper]

Well, Lippert Tech Support said I need 4" of clearance between the tire and frame, so it seems that their kit will not work after all, as my clearance is 3.5".

I left a voicemail for a Dexter Tech Support rep and emailed a Roadmaster rep with my measurements.

Not sure if I could use something like this instead:

https://www.amazon.com/gp/product/B0...k_ql_qh_dp_hza

I had no idea that it would be so complicated to try to find shocks to install on a smaller travel trailer. Seems that there a great niche for a machinist/engineer.

[V'sGlassSleeper]

After reviewing all the kit parts, my mechanic said we'll have to just find brackets and baseplates on our own and he will modify them to fit some Monroe shocks suitable for travel trailers. From all of this, I have learned that the manufacturer's tech support are not an accurate resource for determining if their product is suitable for a given application.


I am scratching my head why all the travel trailer parts stores that I contacted this week told me that they do not sell individual brackets and baseplates. I even called an few off-road service and parts centers and they said that they don't sell them either. What? Where are the guys who do all the after-market mods to their trucks, quads and motorcycles getting their parts? Someone has to be manufacturing and supplying them. The investigation continues.

I'm looking online now at: https://www.4wheelparts.com/b/suspen...ount/_/N-cm7ln