Here is a photo of my Ex and 33 ft travel trailer, The trailer sits level but the rear sags, I think I need to upgrade the rear springs or shocks, which one should it be or both?

 

What is your tongue weight? Probably rather high since the tandem is far aft, that's good because that reduces sway. From your picture I can not tell if you're using WDH.

You probably need a WDH and Rear Sway bar (at least) or RAS. My preference would be Rear Sway bar, WDH and springs on all fours.

Our towing sherpa (WE3ZS), will be along shortly to guide you.

 

Yes it has the 10,000lb Equilizer WD bars, the Ex has a rear sway bar already

 

You and I both need air bags for our rigs.

 

If you enjoy the soft ride while not towing then IMO airbags would suffice.

 

Nice looking combo!
We looked at a few of those bunkhouse models with the bike/cargo door in the rear bunk room. That storage space must be properly planned for when setting up the towing combo though. You can stash a whole bunch of heavy stuff in the area and throw off the trailer balance if you are not careful. Have you weighed the Ex TT combo yet? If not this will help get you to a good scale with 3 scale pads (steer, drive and trailer axles). CAT Scale Locator | CAT Scale
Before you get your weights read this great write up on getting the most from your rig by getting the weights set correctly. RV.Net Open Roads Forum: Towing: Travel Trailer Hitch Set-up Procedure
It does look like you have a little too much rear squat, more spring strength will help a lot there, shocks will not do anything for the squat, they only dampen the spring's oscillations they don't help carry any of the weight. Spring help can be from Air Springs (bags), RAS or add-a-leaf (leaves...) or swapping to heavier springs (like B or C codes from a SD pickup). Pros, cons and opinions a plenty on each choice, we can offer input on all of them but in the end the choice is yours and you should make your informed choice based on exactly how you use your EX, what you expect & hope from the mod, what type of "ride" you will be happy with and of course the great equalizer, your budget!
When I first looked at your photo I thought the trailer looked just a little higher at the front than rear (could be could just be my eyes, pic angle , shadows etc.....), if anything you would want to be a little lower at the hitch end. The higher the tongue of the trailer the more it will invite sway at speed (one of the worst possible things to experience with a trailer!) and having it just a tad lower will keep it level under hard braking as the tow vehicle's nose dives and rear rises. You will want to keep this in mind as you add to your EX's rear suspension (whatever way you go) as that rise will also lift the hitch and trailer tongue higher, an adjustable WD hitch head or longer drop head will be needed to keep the proper trailer attitude.
How does the combo handle currently? At highway speeds and with large trucks passing? Braking into curves at speed? Under semi-hard braking? In strong crosswinds? Would you be comfortable towing as is for a long haul over any terrain? Do you always run with the same (or nearly so) load in the EX and trailer? Does the EX's steering feel a little light with the current setup? Honest thoughtful answers to these questions will help to get the rig dialed in for the best towing setup.

 

All good advice above^^

Would having the tt tongue height be a tad higher in front give a little more tongue weight and therefore lessen the chance of sway?

 

Nice looking setup. As far as setup on the WD hitch goes....you need to get more pressure on the bars to move some weight to the front axle. You may even need 1200/12000 pound bars!

 

No, actually just the opposite, raising the tongue above level would provide less TW and that would only help to encourage trailer sway.


Very good point 1 EX, but I would like to see him get good accurate weights before he starts to spend money on anything, at least then he would have a good baseline to work from.

 

I have found that before I retract the tongue jack I tighten my WD bars that way when I retract the jack the WD loads the front axle more.

Do you have an adjustable ball mount or fixed? when you start to adjust the truck suspension you will need to readjust the trailer's ride height.

 

I have an adjustable ball mount, I guess I need to start there and get it all weighed out, when I hooked this trailer to my step dads 2005 f350 dually, it didnt sag at all, guess I might need them springs

 

Is that with stock springs? I cannot imagine towing with stock springs, the ex by itself feels wallowy and unstable, let alone with a trailer. I would go springs and bags myself. Your non towing ride would improve as well.

 

long before you buy any parts, you need to spend an hour or two at your local CAT scale.
I just bought a new and larger trailer, and here's how I plan on doing it
1) get weight of both truck axles with no trailer
2) get weight with trailer and WD bars unhooked
3) hook up WD bars, weigh all three axles.
4) adjust WD bars, weigh again
5-6-7 - keep weighing as many times as needed to get it the way I like it.

 

I think that B codes and air bags might be overkill for his setup while using the properly sized WD hitch, of course we will know better once he gets his scale weights. I pull a TT that weighs 11k and has a 1400+ lbs tongue weight with 1400lb spring bars in a Hensley Arrow hitch using only molded B codes and the ride and performance are pretty good. Getting the combo dialed in with accurate weights and quality gear makes a huge difference in towing comfort.

 

WE3ZS
Can you shed some light on how having the hitch height slightly up from level changes & reduces the tongue weight and induces sway?

Is it strictly under braking you don't want the tongue "pushing up" on the ball therefore changing the slight angle of the bars, therefore lessening the effect of the bars?

When I tow my TT I have it about an inch higher up front than level. It's a 26'. I have no issues re sway.

I have a very clear understanding of how the WD Hitch works and do use it.

I've always believed on a tandem you run it a touch high, as in just above level, and on a single axle the opposite.