Suspension Enhancements for Single Axle Trailer

Great responses, after looking at the design, lowering does not seem to be an option. I will double check the axle load rating, it could possibly be #4200, it is definitely beefier than a 3500# axle, and has stock 15" 6 lug wheels.

Gman

Grodyman wrote:

goducks10 wrote:

GDS-3950BH wrote:

Cummins12V98 wrote:
Personally I like the Dexter Torflex axles, I recently dumped the traditional spring setup on my boat trailer and also added disk brakes with hydraulic actuator. WELL worth the upgrade!!!

Nice install!

Having been up close and personal with the frame Keystone uses on the Passport line, I would be skeptical if would handle some shock mounts without a lot of reinforcing. OP doesn't say the year, but prior to 2013 they used a frame made by Dexter, after 2012 Lippert, two different animals there. The Dexter frames were stout, the LCI are recycled soup cans.

The nice thing about Torsions is the tube acts as an additional crossmember adding overall strength. In the case of the Passport if it is a model with the LCI frame, the OP would want to add a tube to the bottom of the frame rail at least 2" X 2" X 4', probably top to bottom flange gussets inside and out at the end of it, and probably the Dexter 2-3/4" lift bracket between that and the Torsion. I would doubt he can not get enough ground clearance without doing if only counting on the start angle.

Haylet RV has a good video walk around and you can see that the spring hangers are welded to a 2"x2" tube spacer already.
I'm not sure the OP can actually lower his TT. Looks like the 2"x2" tube spacer is there for tire clearance.

Does this mean a torsion axle will not work?

Additional height is probably one reason for the 2x2, but the main reason is reinforcing for the 10 or 12 gauge soft steel used by LCI to make those machine welded beams. They do all sorts of things where hangers are attached, most of them better but none of them good lol. Thats the nature of LCI and you can find many examples of twisted frame rails or ripped off hangers if you search around on their junk.

No it doesnt mean torsions wont work, they would actually be better because the axle tube acts as a solid crossmember. You can get about any ride height you wish by adding a tube or Dester bracket, or what start angle you choose. Passports usually have a high ride height due to the box and wheel well design.

John,

SOME manufactures use smaller axels than GVWR, the remaining made up with hitch weight......again some!

My old 92 Fleetwood had a 6000 gvwr, yet it had two 3500 gvwr axels, tires, rims etc under it. I personally had no issues loading it up higher than 7000 lbs total, with usually 6000-6600 on the axels, remain hitch in the 600-800 range. This variance also depended upon how long, or where we were going......

Of course, if one wants to throw equipment trailers into the mess. They give the payload as the sum of the Axel(s), with a quote, of hitch weight being the weight of the trailer! So a dual 3500 lbs axel trailer, that is empty wt of 2500, can carry 7000 lbs with 2500 lbs of hitch weight! be it a ball/pintle, or a 5w.......

So it could be possible, that the OP does have a 5000 lbs suspension. BUT the manufacture has put a smaller gvwr placard on it for some other reason...... of course like ALL GVW vs GAW debates, which is correct and why is another issue all of its own.

With that said....... many ways of fixing said issue(s), whether it is cost effective or not is another issue too.

Marty

Grodyman wrote:
I have a Passport 153ML, which although a lightweight, is a pretty tall windsail, and sits high on a 5000lb 6 lug axle with traditional leaf springs.

I am toying with the idea of converting it to a torsion axle to smooth the ride and maybe lower a bit. Worth the expense?


I can't seem to find a suspension enhancement product rated for 5000lbs and made for a single axle trailer, all the MorRyde/Equa Flex/etc. are mostly for tandems.

Gman

Hi

Trying to help. You stated you have a 5,000# 6 lug axle setup. Where did you see this listed? I agree 6 lug, you can see it on the wheel, but the 5,000# does not seem to fit, or Keystone changed your camper and not their brochure.

Is this your camper? The 2018 Passport 153 ML in this brochure?
https://www.keystonerv.com/media/9142021/passport_brochure_2018.pdf

They list the dry weight as 3,514# with a payload of 1,085#. That adds up for a 4,500# GVWR. What does the VIN sticker say your camper GVWR is rated for and do they list the suspension rating?

Knowing Keystone, it is odd they put 5,200# axle tube with 5,000# of springs on a camper with only 4,500 GVWR. Keystone many times will put the suspension less then the GVWR on certain models and let the truck take some tongue weight. To save money, they could of put a 4,200# axle tube with 4,200# springs and let the truck hold 300# and meet the 4,500# GVWR.

Aside from that, I agree with the others, adding shocks will help. I do not agree with airing down the trailer tires unless you know exactly what your wheel weights are and still have some level of excess tire capacity. Ideally 15% extra capacity over the heaviest wheel.

The torsion axle needs a reinforced trailer frame above and beyond in most cases, then the leaf spring mount. This is what some posters were talking about adding the 2 x 2" tube on the bottom of the frame. But that may not work if the main frame is just too thin for a torsion setup. TT frames are not anywhere in the heavy duty cagatory, and ultra lights are even less duty.

Lowering the camper, the tire bump clearance was brought up. Dexter axle recommends 3" of bump clearance from top of tire to inside of the fender well. While 2 1/2" will just get by in some cases, it would be odd for Keystone to add lots of extra bump clearance to allow you to lower the camper. You may not be able to do it. Check and see.

If your wanting to lower it 2 to 3" or even 4 1/2" for getting better towing mpg, odds are it will not affect your towing mileage to where you can find it. The air drag is still too great.

To your question, is it worth it to spend $$$$'s on a torsion axle to help ride and lower MPG, I would say no. Yes, add shocks, they will make a difference in trailer ride and help the entire trailer from frame excess flexing.

Hope this helps

John

I put shock on mine and it really smooth it out, but i'm tandem. it should work for you also. lowering is not so easy if you don't have tire clearance in the fender well. for the cost and return of an axle change your not going to gain much, your spending a 1000.00 to save 800.00.i would try the inexpensive things first, and maybe a cab high canopy to try and get the wind up over the trailer. also you may have to adjust your driving habits for better mileage.
Jay D.

Honestly I don't think you can lower it but maybe a few inches because of the big tires you're running. A few inches won't do diddle for the mpg's. You already have a sloped front on the TT.
With your F150 Eco you should be in the 10 mpg range. How fast are you towing or is it mainly hills?
Heck I get 8.5-9 mpg towing an 11'6"H 31' 9500 lb TT with a 2500 6.4.
What you might do is measure the distance from the top of your tire to the underside of the TT and see if you can actually lower it.
As for the ride adding shocks would be the 1st option IMO. I've had shocks on my last 3 trailers and it makes a big enough difference to warrant them.
The other option is a canopy for the back of the truck.
Or maybe get some softer leaf springs that will still handle your TT's weight. You could easily be oversprung.

I was thinking of lowering the trailer a couple inches, while at the same time upgrading the ride. Everything about the Passport ultra lite is pretty cheap, but I like the trailer.

The height really affects MPG with my truck, I got as low as 7.5mpg on one stretch, with a 23 gallon gas tank. Not that the trailer rides bad per se, I did upgrade tires to LRE, trailer is 3500 dry, no more than 5K loaded.

I really wanted to install an equa flex or equivalent product, but do not see one for single axles.

Gman

I have heard that trailers with independent torsion axle tow much smoother and handle bumps much better.
Shocks help with wind.

What Scott and blt2ski said.
Be more specific with your issue, aside from height (wouldn't mess with height by modifying suspension unless you can do a simple spring under axle flip and have the clearance at the wheels to do it.
Smooth the ride? Is it riding to "stiff"? I.E. The springs are actually overkill for the weight (an uncommon TT occurrence) or is the suspension seeing plenty of flex but it's bouncy?
If the springs are suited for the weight then shocks would help.
If the springs are too stiff, then lowering tire pressure (assuming additional tire capacity would help).
Although a simple issue, there are about 3 potential causes of an "unsmooth" ride.

Torsion axle, IMO is not necessarily the answer unless you size it for the actual weight.
I.E., a 5k torsion axle on a 3k trailer will still ride maybe rougher than you're wanting.
My boat trailer is an extreme example, twin torsion axles, rides great with 4000lb + boat on it. Like a rock empty.
My 7klb enclosed trailer twin torsion axles, about 3500lbs empty, rides bad (hard and bouncy) empty. Smooths out once my total weight is about 5klbs or more.

goducks10 wrote:

GDS-3950BH wrote:

Cummins12V98 wrote:
Personally I like the Dexter Torflex axles, I recently dumped the traditional spring setup on my boat trailer and also added disk brakes with hydraulic actuator. WELL worth the upgrade!!!

Nice install!

Having been up close and personal with the frame Keystone uses on the Passport line, I would be skeptical if would handle some shock mounts without a lot of reinforcing. OP doesn't say the year, but prior to 2013 they used a frame made by Dexter, after 2012 Lippert, two different animals there. The Dexter frames were stout, the LCI are recycled soup cans.

The nice thing about Torsions is the tube acts as an additional crossmember adding overall strength. In the case of the Passport if it is a model with the LCI frame, the OP would want to add a tube to the bottom of the frame rail at least 2" X 2" X 4', probably top to bottom flange gussets inside and out at the end of it, and probably the Dexter 2-3/4" lift bracket between that and the Torsion. I would doubt he can not get enough ground clearance without doing if only counting on the start angle.

Haylet RV has a good video walk around and you can see that the spring hangers are welded to a 2"x2" tube spacer already.
I'm not sure the OP can actually lower his TT. Looks like the 2"x2" tube spacer is there for tire clearance.

Does this mean a torsion axle will not work?