Sulastic Spring Shackles

[GCroyle]

TDR Folks,

A FRIEND with a Ford F250 6.7L 4WD has had a bout with the death wobble and has it under control. Doesn't want to go there again. But as they are full timers towing a 30' Airstream and a bit adventurous they are traveling unpaved roads looking for fishing streams etc.

He would like to improve ride etc (serious back injury finally got surgical relief, a real hard landing in a Military helo he was piloting decades ago powertrain failure IIRC) and new shocks are in order but he's asked me about Sulastic Spring Shackles. http://www.sulastic.com/ I'd never heard of these so TDR any knowledge to share from you installing and owning these that I can share with John?

Thanks,

Gary

 

[SnoKing]

TDR Folks,

A FRIEND with a Ford F250 6.7L 4WD has had a bout with the death wobble and has it under control. Doesn't want to go there again. But as they are full timers towing a 30' Airstream and a bit adventurous they are traveling unpaved roads looking for fishing streams etc.

He would like to improve ride etc (serious back injury finally got surgical relief, a real hard landing in a Military helo he was piloting decades ago powertrain failure IIRC) and new shocks are in order but he's asked me about Sulastic Spring Shackles. http://www.sulastic.com/ I'd never heard of these so TDR any knowledge to share from you installing and owning these that I can share with John?

Thanks,

Gary

Hopefully his new shocks on order are Rancho 9000 adjustable for the rear if he is looking for a smoother ride. I had them on our 2001.5 for years and ride difference was very noticeable. I have been thinking about putting them on the rear of my 2015. New stiff non adjustable shocks will not soften the ride.

The Sulastic shackles will help also.

Also if the F250 has a rear sway bar he might try disconnecting it on one end to see if that improve the ride. He is not dealing with a tall load, so not having the sway bar in the picture is not a problem. I tried that on my 2001.5 and it help with ride.

Another thing is to inflate rear tires to the actual load they are carrying. Some seem to think that because the door sticker or tires state 80 lbs that is what they should always be at vs inflating them to actual loads.

 

[GCroyle]

SnoKing,

I'll advise John, your comments. Inflating to actual load, interesting.

Gary

 

[SnoKing]

SnoKing,

I'll advise John, your comments. Inflating to actual load, interesting.



Gary

Door stickers are for max mated load per axle max rating.

 

[Ozymandias]

Air ride seats are the solution.

 

[AH64ID]

Proper tire pressure for the load and good shocks are in order.

I have the opposite opinion of Rancho 9000's. IME they are overpriced and under-performing, and not worth 1/10 of their cost. I got sucked into their hype on multiple vehicles and didn't know any better until I tried something else. Rancho won't ever get another penny from me for shocks.

Bilstein shocks are my current favorite and have preformed 10x better than Rancho.


As far as the sulastics I have never liked the though on a HD pickup that is used heavily. I want a solid leaf spring connection. If he has the proper tire pressure and gets good shocks he may be surprised. If it's still too rough he could look at custom leaf spring, maybe with an airbag for the increased load and a softer spring like the auto-level Ram's, or air ride seats as Ozy mentioned.

 

[GCroyle]

Guys,

Thanks for the ideas. In particular this KISS approach SnoKing and others mentioned.

Another thing is to inflate rear tires to the actual load they are carrying. Some seem to think that because the door sticker or tires state 80 lbs that is what they should always be at vs inflating them to actual loads.

I talked to John and I think he's now convinced to start right here at PSI. Simple, minimal effort no $ and starts at one change at a time.

They are full timing and the tires are inflated for full towing loads but when he parks for a while doesn't adjust to a lower w/o trailer PSI then bump it up on towing.

I'll keep checking in with John he might pursue mechanical moves yet but this PSI is too simple to not start there.

I admit to doing the same thing but when we're driving around it's not on unpaved roads. Oz I'll go back and look but IIRC Mike set you up with air ride seats.

Gary

 

[SnoKing]

Guys,

Thanks for the ideas. In particular this KISS approach SnoKing and others mentioned.



I talked to John and I think he's now convinced to start right here at PSI. Simple, minimal effort no $ and starts at one change at a time.

They are full timing and the tires are inflated for full towing loads but when he parks for a while doesn't adjust to a lower w/o trailer PSI then bump it up on towing.

I'll keep checking in with John he might pursue mechanical moves yet but this PSI is too simple to not start there.

I admit to doing the same thing but when we're driving around it's not on unpaved roads. Oz I'll go back and look but IIRC Mike set you up with air ride seats.

Gary

I carry a clip on tire inflator with a quick connect for the air hose. If you simply clip on the valve stem it makes a good deflator. I actually can tell when I get to the low 40's by the change in the sound of the air rushing out.

 

[slowmover]

The Sulastics go way back in time. Circa 1979 or so.

BF Goodrich Velva-Ride

They’ve been sold a time or two.

The “problem” of traveling distances is

Vibration-Induced Fatigue

The reason these “work” is
isolation & absorption

Changes the linearity (rigidity) with transmission of vibratory frequencies.

A partial de-coupling.

Tire pressure is the biggest offender. It must be to scaled load. Not imagination.

An Airstream is easy to pull. A 3/4 or 1T is overkill.

A pickup is needed where the bed load brings the truck to near it’s spring capacity. No different than for a car or SUV that’d be a better choice for road miles.

RV’ers have somehow concocted a story that tongue weight is part of payload. It isn’t.

Tongue Weight is a placeholder number

It represents ONLY the static load at rest of the lever extending from hitch ball to trailer axle center.

The problem to be solved involves dynamic changes while underway. The forces seen at the hitch vary over a range of thousands of pounds. Can go deep negative to badly positive, and do it almost instantly.

A Weight-Distribution Hitch is about spreading resistance to compression over BOTH vehicles, versus at a single point behind the tow vehicle. (Same for expansion, so to speak). Slows the rate of changes affecting steering.

The word “weight” regards the tongue and the hitch are where 96% stop thinking.

The game is to keep the TV Drive Axle connected to the pavement.

At which, solo, pickups (live axle) are the worst vehicle possible. Hitched makes it worse.

Too much spring capacity (for the solo load) makes it worse yet. AND worsens the ride.

Controlling tire/spring motion (damping) while towing is:

1). Better vehicle choice for true load (not the 16-yr old ego) so that “loaded for camping with all passengers aboard” is the true specification for maximums (Axle Values, not bogus “Payload” or “Tow Capacity”.)

2). The weight of passengers & gear needs to be wholly between the TV axles. The closer the FF/RR weight balance is to 50/50 BEFORE hitching is a goal. Passengers belted and all else secured against any movement.

3). Ideally, a WDH returns the Steer Axle to the Solo value (all else the same). TW distributed by thirds to Steer, Drive, Trailer.
The crap OEM & aftermarket hitches DON!T allow this leverage to occur without modification on a long-wheelbase stiffly sprung vehicle. The vehicle frame absorbs too much of the applied leverage.

Hitch extensions ALL THE WAY TO THE DRIVE AXLE are what work. Diagonals. The way we had hitches built in the 1960 and 1970s. The receiver tube also extended and cross-braced.

The spare tire goes to the bed. (Torklift kit).

Less leverage to achieve desired WD results means ideal tire pressures are obtainable. Desired WD results means combination vehicle dynamics are damped.

No single point of aggravation, as with badly set WDH rigging (that’s “you” and everyone you know).

The trailer MUST be dead level (FULL fresh water & propane plus camping load). A carpenters level across the door threshold must be in bubble or close after everything else is done.

4). Dead-level trailer and TV at 50/50 before hitching are the thing. WDH adjustments ate just fine-tuning where the Steer Axle is the same value with/without trailer in tow.

— the combo rig must stop sooner than the laden TV solo.

— steering is such that the rig continues in the lane hands off at 60-mph for a long count of three without heading for the ditch

— passing big rigs mean any steering correction is a CONSTANT single set of degree & duration, not multiples.

— with an AS, fuel mileage is NOT more than a 40% penalty where all else is the same
(as none of you know what the TV is capable of in fuel burn, it needs its own test. 200-mile loop on Interstate back to same fuel pump at either 58 or 59/mph 100% on cruise control).

That’s the baseline set of tests.

Vibration is a bear to chase and cage. Affects me badly as I’m getting to where I can’t work.

Vacation should be fun. An oversprung and unstable pickup is the wrong start to that.

Great shocks, etc are a good idea. The Velva Rides (or MOR/ryde version) another.

But nothing will overcome flat bad toe vehicle spec and bad hitch rigging.

My ‘04 Dodge (6860-lbs ship weight) is at 8,940-lbs as a driver. 40-lbs variance all four corners. Then I hitch. Drive Axle is near or at capacity while Steer is close to Solo value.

PURPLE brand seat & lumbar cushions in the Peterbilt allow me to still work. They’re great in the Dodge, too.

When I no longer need the pickup (my ex-business vehicle) as garage & store room, I’ll go back to using a car to pull my 35’ Silver Streak. All of North America and most of Mexico pulling a near-identical trailer with a car is how I grew up with Dad & Grandad.

One needs enough and not more. Ride quality is spring spec for the load. Not imagination.

There’s not an Airstream ever built needs a turbodiesel 1T. Today’s grossly overpowered 1/2T (or, better) SUVs with fully independent suspension are in all ways better. Especially ride quality.

What gear MUST go in the truck bed? Not convenience. Safety. Weigh it separately.

Camping is some extra clothes and food on board. It’s the newbies that pack way too much and never use it. The learning curve for us all.

A 3,000-mile vacation where the 31-miles of off pavement is used for TV spec, is bad specification. Re-think.

Band aids help, but won’t cure.

.

 

[GCroyle]

Slowmover,

John has been full timing for over three years and owned Airstreams before they both started FT. He's not changing his truck it carries the supplies for their fun and self sustaining see the USA retirement. IIRC for them, Alaska was a summer trip about 5 years ago. As I replied he's going to review tire pressure first, easiest approach.

Gary

 

[Cummins12V98]

I carry a clip on tire inflator with a quick connect for the air hose. If you simply clip on the valve stem it makes a good deflator. I actually can tell when I get to the low 40's by the change in the sound of the air rushing out.

At your age you can still hear???

 

[SnoKing]

At your age you can still hear???

Yep and able to read sarcasm also!

 

[Wayne M.]

Gosh. Any F super duty with a bed ive driven rides like a buckboard! I’m with Ozy- air ride seat. Other than that, I’m a leaf spring fan, but if I needed the smoothest ride, I’d be looking at a newer coil sprung Ram.

 

[TFucili]

Or go hog wild, and full Kelderman.

 

[DonFitzwater]

Gosh. Any F super duty with a bed ive driven rides like a buckboard! I’m with Ozy- air ride seat. Other than that, I’m a leaf spring fan, but if I needed the smoothest ride, I’d be looking at a newer coil sprung Ram.

My coil spring equipped 2500 is horrid. I'll be swapping to rear air from Kelderman if I keep it. My wifes 3500 leaf/air rides better than my 2500.

 

[Ozymandias]

My coil spring equipped 2500 is horrid. I'll be swapping to rear air from Kelderman if I keep it. My wifes 3500 leaf/air rides better than my 2500.

Just swap out the coils for airbags - problem solved. No need for kellerman setup.

 

[slowmover]

Slowmover,

John has been full timing for over three years and owned Airstreams before they both started FT. He's not changing his truck it carries the supplies for their fun and self sustaining see the USA retirement. IIRC for them, Alaska was a summer trip about 5 years ago. As I replied he's going to review tire pressure first, easiest approach.

Gary

— Vibration is the issue. That’s systemic , not per component. (Fatigue, early-induced.)

Run him thru your own Three-Pass Scale Method ticket set. Without a baseline (corrected) chasing ride quality problems becomes circular and dissatisfying.

The OEMs group this as NVH

NOISE

VIBRATION

HARMONICS

They are the same (to the human). Interrelated. (And a whole other subject).

But that set assumes driveability problems are solved. Which can be tested. Proved.

For trailer owners it is always incorrect hitch rigging as the fundamental to all other problems farther along the decision-tree of diagnosis. (99% failure rate seen at every campground).

I have to do the same “hitch rigging” with a 53’ trailer. Get the fifth wheel located so that it always starts loading the Steer Axle. And then position the Trailer Tandem Axle Set so that the split is evenly weighted between them and the Drive Axles (where fuel weight is accounted and a slight bias given the Drives).

Can a 58,000-lb trailer really be adjusted so that shifting but 1,800-lbs of load makes a difference in steering, handling & ride quality? (Ha!)

It’s no different.

A fifth wheel travel trailer loads Steer & Drive so that the Steer is the same +/- as when unhitched.

It’s no different.

It’s the conventional TT owners who fail to do some baseline work. But given a quality TT design, the finished result is better than ANY 5’er, as those are the true rollover kings.

Using a Cat Scale for the 3-Pass is for sixth graders in difficulty. And, it’s impossible to set tire pressures to load without it.

— Tire wear isn’t the gauge.
— Chalk line across tread isn’t it.
— Guessing sure as hell isn't it.

The Cat Scale phone app is everyones’ friend.

That is where one “starts” someone else.

.

 

[Wayne M.]

My coil spring equipped 2500 is horrid. I'll be swapping to rear air from Kelderman if I keep it. My wifes 3500 leaf/air rides better than my 2500.

Never drove one. A co worker has a ‘18 and he says it’s better than the Fords on the job. That’s what I was going by.

 

[DonFitzwater]

Just swap out the coils for airbags - problem solved. No need for kellerman setup.

As far as I can tell, the Kelderman is just airbags.

 

[DonFitzwater]

Never drove one. A co worker has a ‘18 and he says it’s better than the Fords on the job. That’s what I was going by.

If it's got 1k to 2k pounds in the bed it's great, empty is bad news. I usually have a steel 200 gallon fuel tank or water tank in the back just for ride quality improvement.