Newby Asks: Travel Trailer Shock Absorbers

[RUSSELL5000]

I have looked at a lot of travel trailers, bumper-pull as well as fifth-wheel. I don't see shock absorbers.

I am sure some trailers have shock absorbers, but it is clear that most do not.

Why is this?

 

[crispyboy]

I have not seen them on any trailers except Airstream. They have used them since the 1960's. My uneducated guess tells me that it help control the independent suspension and keep the trailer planted on the road.

 

[JLandry]

It's a cost-saving measure I suspect.

Mine came with them, but if it hadn't, I would've added them.

You'll find many travel trailer manufacturers also don't bother to balance the tire / wheel assemblies. That's another cost-saving measure they expect won't be noticed.

John L.

 

[ScottLewis]

Cost and weight.
There is a lot of debate about the actual need for them. I've owned RV's equipped both ways and still can't give you a definitive answer. I added shocks to a 28' Komfort pull trailer some years ago because it was a bear to tow, especially behind my Ford Bronco. It may have helped with stability but marginally. Some say tires wear better with shocks but again I don't know. Tires wear faster on my trailers than they do on my truck but IMO they should be replaced every 3 or 4 years anyway because of age deterioration and that's about when they wear out for me, at about 15 to 20K miles.

 

[NIsaacs]

I would say it is mostly due to clearance issues. With a straight frame and mostly tandem axles with equalizers there is not enough room for a shock to fit/work.

Nick

 

[BLNRAY]

My Kountry Star came with shocks,it's a 2001 5th wheel

 

[Kirwin]

My 2008 HR came with shocks. Ken Irwin

 

[wyosteve]

My 06 Arctic Fox 5th wheel has shocks.

 

[jelag]

My RV came with the shock hangers but no shocks... when I went to install the shocks I found that the hangers on the frame were welded in the incorrect position... I had to remove them and re-weld the bracket to the frame...

 

[RUSSELL5000]

Thanks, guys.

I see that a shock kit is offered and it does not look that expensive. It would require welding the hangers to the frame, which makes me a little hesitant because (1) it is welding to the frame, and (2) it is all covered up with a plastic-like underbelly membrane and insulation. I assume the underbelly membrane will want to melt, and so I will need to move all back and then put back in position.

Kind of wondering whether the benefit justifies the effort.

Thanks!

 

[Bob4x4]

The short springs reduce the importance of using a shock.They will help some.

 

[Joseph Donnelly]

Leaf sprung trailers ride a lot rougher than torsion axle trailers like Airstreams and those with Dexter Torflex axles. Yet, leaf spring trailers almost never come with shock absorbers because th whole idea of a leaf sprung trailer is generally to sell it at the lowest possible cost. The main advantage to the leaf sprung dual axle system is that it is tolerant of having the trailer tilted up or down at the front. Such a stance is still a bad idea, however.

 

[JLandry]

...makes me a little hesitant because (1) it is welding to the frame, and (2) it is all covered up with a plastic-like underbelly membrane and insulation. I assume the underbelly membrane will want to melt, and so I will need to move all back and then put back in position.

Not necessarily...

If you have room to insert a piece of sheet metal directly above where welding as a heat barrier, that should be adequate to prevent the plastic underbelly from melting. We recently had some welding done on the frame of our travel trailer and the welder used a heat shielding gel (something I didn't even know existed) AND a piece of sheet metal to protect the underbelly. It worked like a charm with no damage despite the close proximity of his welds.

Best regards,

John L.

 

[AH64ID]

The current version of my TT has shocks, and mine does not. I looked at adding them and I don't have the clearance to do so. The new trailer has a 3-4" wider axle which gives more room between the brake and frame for a shock. If I ever need to replace my axles I will go wider and add shocks.

I did add a Dexter EZ-Flex to the suspension and the ride is MUCH MUCH better. My wife even commented on it from the passenger seat.

Leaf sprung trailers ride a lot rougher than torsion axle trailers like Airstreams and those with Dexter Torflex axles. Yet, leaf spring trailers almost never come with shock absorbers because th whole idea of a leaf sprung trailer is generally to sell it at the lowest possible cost. The main advantage to the leaf sprung dual axle system is that it is tolerant of having the trailer tilted up or down at the front. Such a stance is still a bad idea, however.

Torsion setups only provide a better ride when loaded near their axle rating, if they don't have at least 30-40% of the weight on the axle they are worse riding than leafs and don't really ride better until above 60-70% loaded.

Another big reason that many TT's don't come with torsion axles is ride height, my same trailer with torsion axles would be 4-6" lower and I wouldn't have bought it. There are advantages and disadvantages to both, it's not always about cost.

My dad just had a Mirage trailer built and they strongly advised against torsion axles since his normal weight was going to be about 3K lbs max in a 7K lb trailer. I have heard the same information from other manufacturers.

 

[RUSSELL5000]

AH64ID: My travel trailer has the Mor-Ryde equalizer. I think the concept is similar to the Dexter EZ-Flex.

What would make me want to add shock absorbers - if the trailer is "bouncy?"

Thanks.

 

[AH64ID]

I want to add shocks for stability on dirt roads, the trailer rocks a lot where I camp and I figure that shocks would be easier on everything.

 

[Kirwin]

My RV came with the shock hangers but no shocks... when I went to install the shocks I found that the hangers on the frame were welded in the incorrect position... I had to remove them and re-weld the bracket to the frame...

I found this out after the third set of shock rubber pieces were eaten through by the shock rod. Lippert's 17 yr old with a mig gun wasn't putting then on at the correct angle. Cut mine off rewelded them back on using the shock as a template and no more problems in 40K towing miles. Ken Irwin

 

[Shadrach]

My Canadian built Peak Frontier had the brackets already there so I added shocks. I added them so things wouldn't bounce around so much on rough roads. No one rides in trailers so I guess they figure the ride doesn't need to be so smooth. David

 

[slowmover]

.

The high end travel trailers had shock absorbers from the 1960's onward, upmarket from Airstream: Silver Streak and Streamline. Optional on the "bargain" models and standard otherwise. These two manufacturers stayed with leaf spring through the end of production, 1995 (one or two years of torsion at very end) and 1974, respectively. AVION went through several suspension designs over the years and had a Henderson walking beam design (MOR-ryde) in the '60s/70s, then a stub axle leaf sprung set up that separated the opposing sides from one another. (Some one ask ol' Uncle Harv, he had a couple of these).

Cost, here, was not an object as these trailers easily cost as much as the average American house back in the 1950s-1970s. The market, and society changed, and Airstream survived only because one deep pocket manufacturer wanted it for a prestige brand. Gotten mighty heavy the past generation for a given length, but no comparison to other TT designs now available. Airstream still uses shocks on their torsion axles . . and has no plans to change this after more than fifty years. They work here as well.

Shock absorbers are more than worthwhile as they dampen the action of the springs . . otherwise the tires have to take the load "peaks" and that adds to tire heat. Slowing the rate of movement means most on the worst roads, and in situations where the opposing side tires are meeting different obstacles.

Spring mount cross-members were also stock on SS trailers (too many years -- decades -- since I looked under my grandparents Streamline). I think we all know to keep travel trailer tires to full sidewall air pressure as the forces acting on the tires in turns wants to tear the tires from the wheel. The leaf spring is also acted upon. Cross-member and triangular gusset to the spring mount are both good ideas. Not the same as a Panhard rod, but keeping forces in place is part and parcel.

Fancier equalizers tend to increase wheel travel. The main advantage of torsion axles is that one has now a truly independent suspension due to both wheel travel increase and being uncoupled from the other axle AND that the roll center is considerably widened as a result. On a leaf sprung trailer the "outer edge" is at the spring clamp, with the torsion axle it is move to the face of the wheel. Note how much trailer is "outside" the spring clamp when viewed from rear. A torsion axle trailer is much more stable as a result. Torsion axles are a true upgrade . . their downside is that they tend to "dry rot" or "lot rot" when not exercised. Service life is shortened from maybe 20 to 15 years (many conditions apply). They are also dirt simple with next to no parts as compared to L-S.

Low center of gravity is always good, but torsion axles are what make it work:


"Why Airstream?"






MOBILE OUTFITTERS (LIPPERT aftermarket catalog) has upgrade kits in re shocks, etc.
And a DEXTER dealer can help convert to torsion flex.


John Barca on TT shock absorbers

http://forums.woodalls.com/index.cfm/fuseaction/thread/tid/24776971/srt/pa/pging/1/page/1.cfm


John Barca on Spring Hanger Cross Members

http://forums.woodalls.com/Index.cfm/fuseaction/thread/tid/24796694.cfm

.

 

[RUSSELL5000]

slomover,

Thanks. A conversion to torsion axles is far out of my budget. I also don't have the hop and tools that John Barca does. I wonder if a kit would be beneficial.

I have found the following kits:

I have done web searches and have found two kits that are available:

Camping World: Shock Kit for 3-Inch Axle Tube - Mobile Outfitters (Lippert) 281281 - Shocks - Camping World

JoyRider: http://rvimprovementsystems.com/joy_rider.html

Has anyone retrofitted shock absorbers on their travel trailer using a kit?

If so, which one?

How do you like the results?

Thanks!



Has anyone retrofitted shock absorbers on their travel trailer?

Did you use a kit, and if so, which one?

How do you like the results?