Tower novice - Car badly affected - help please...

[Thomas G.]

It would be nice if you could borrow a set of wheels with tires mounted and do a test run.

[Francesca Knowles]

Originally Posted by franck2cv

Here the latest news.

I first removed the Battery, the Propane tank, and the jockey wheel to try with a lighter tongue weight. Then hitched the trillium to the subaru. Only went 300 yards and back..... Awful! I switched vehicles, to drive as planned the Mercedes Wagon and Trillium to the RV specialist. The light tongue weight made it worse by far. I thought I as going to brake something. 20 mph max all the way (5 miles).

Verdict: Tires (as expected). The shop owner was really convincing in telling me all sort of horror stories involving P tires on trailers. We then decided to add a small stabilizer as this is a reasonably priced accessory. He ordered the brace to stop the knock between ball mount and hitch. Finally, he offered to drill a second hole in the ball mount to reduce its overhang (2 inches).
I left the trailer there and will hear from him next week. He's also going to check the suspension but with proper ST tires. A quick look let him believe that, even though not in its prime youth, the axle is likely to have a few thousand miles left to do.... we'll see. One thing at the time.

Enjoy the long week end (Canadian!)

Franck

Steps in the right direction! First things first, right? Since these new tires can be used on a new axle should one prove necessary "down the road", you're losing nothing. Although it sounds like the real person that's had a chance to actually look at the axle says it's still got life in it- good news.

It may be of further comfort that at three years of age and showing some wear, you'd likely have been replacing those p-tires sometime soon anyway. At least you're not taking off new p- tires, as I had to do....and I was in such a hurry (behind schedule on a trip) that I didn't even think to keep those brand new tires for resale! ..

Word to the wise, in case you want to have the same guy look at this:
There's what looks to me like an awful lot of grease showing at the hub in your earlier pics...a bearing inspection may be in order.

Keep us posted!

Francesca

P.S.

[Ron in BC]

Originally Posted by Francesca Knowles

There's what looks to me like an awful lot of grease showing at the hub in your earlier pics...a bearing inspection may be in order.

Keep us posted!

Francesca

P.S.

We're going to have to call you Eagle Eye. You're sure good at spoting details in the photos that are posted

And thanks for the Happy Canada Day. Americans do a much better job of flying the flag than we Canadians do but I do my bit. As well as fly an ancient Union Jack that belonged to my British grandparents.

I haven't read back through the posts but I'm presuming at some point that the bearings were checked for slop etc.

Interesting thread, we're all hoping for a breakthrough in the trouble shooting that pinpoints the problem for sure.

[ruscal]

Moving the ball closer to the bumper is surely a step toward success. In the end I would guess the axle is causing the roughness. These torsion axles don't dampen as well as hydraulic shocks which can cause a frequency mismatch with the car. I would also guess that a sacked axle will oscillate faster than a new one, and because of the shorter usable travel bottom frequently causing all those nasty jolts. The wrong tires would probably only cause more wag or sway.
Russ

[gmw photos]

Franck,
You can keep trying to sneak up on the solution one step at a time. But if you really want to solve the problems, go back to my earlier post about the axle being quite simply worn out.

A new axle, and some PROPER tires ( that would be "LT".....stop messing around with those junky azz ST china bombs ! ) will solve the towing issues, along with of course normal procedures for correct towing setup ( correct tongue weight, etc ).
You can buy Kumho or Nexen LT RADIAL tires in a size to fit this.
A good, recent thread to look thru is this one:

http://www.fiberglassrv.com/forums/f...r-58782-5.html

good luck with it, and happy and safe towing !

[Roy in TO]

How are things coming along Franck? It is about time for an update.

[franck2cv]

Originally Posted by Roy in TO

How are things coming along Franck? It is about time for an update.

Hi

Well... there should be more tomorrow! The Trillium is ready but.... I got nothing to tow it with! I had to get a couple of things fixed on the car.
Better be safe than sorry. I should be able to pick both up tomorrow.

I asked the Trailer people to verify the suspension thoroughly and to call me should they be concerned. No news.... Good news I suppose!

I'm still keen on upgrading it anyway but I'm going to keep this as a winter job.

So bear with me.....

[Lloyd (aka Santa) Coltman]

Just some info regarding trailer handling, and rating regulations.
Don't know about other jurisdictions, but in BC, the maximum laden trailer gross weight (including water, food, beer, clothes, cooking utensils, batteries, propane etc CAN NOT exceed 1400Kg OR 50% of the unladen Tow Vehicle weight, Whichever is less, Unless brakes are fitted!!!
Generally speaking, most trailers are set up with the axle centre at 60% or greater point of the trailer Body for positive tongue bias. Very light to negative tongue bias can even shake a heavy truck like the tail wagging the dog. Another point is the ratio of hitch to axle centre/ track width (tread centre to tread centre on tires) minimum is 1.5:1 for good handling. I have two motorcycle tent trailers 1- factory built, O/A Length 9.5 ft, axle centre 2ft from rear end of trailer, track width 36" Critical ratio is 2.5:1. It was a bit too heavy (F/G), and needed 2 people to set it up.
My home designed/built unit can be erected by one person, fully loaded weighs under 250lb, still has a critical ratio of 1.6:1, and I don't have to put my pants on laying down.

[franck2cv]

Just picked up out trailer:
New tires (ST), stabilizer, modified ball mount (less over hang) .......
NO IMPROVEMENT what so ever! People at the shop were so adamant that it would solve everything that I believed them. No need to say that I'm disappointed. They told me the suspension was OK ....

[Brian B-P]

I'm sorry to hear about the disappointment. On the bright side, the problem is being narrowed down:

• It isn't the tires; since opinions on this were not unanimous, at least this resolves one debate. New ones couldn't hurt, and the trailer is set for tires for a few years.
• The shortened ball mount probably helped, but is not a big enough effect and fundamentally doesn't fix the problem - at least it will still be of value when the real problem is fixed.
• If the "stabilizer" is a friction-type sway control device, no one who understands trailer behaviour would reasonably expect this to have made any difference, but if you want one this is a fine time to get one... and again, it confirms that the ride roughness has nothing to do with sway.
• The test-tow with the Subaru already eliminated the Mercedes as the source of the problem.

Originally Posted by MC1

I was in the service, diagnostic, repair business for a large corporation for decades. You always do one thing at a time and test for a difference. That way you understand the effect the change has made and go on from there.

I agree, but the diagnosis determines which thing to do first - the shop seemed to do no diagnosis in this case. They specifically did not assess the axle/suspension in any meaningful way.

Now we're back to the fundamental question: does the suspension work?

Originally Posted by franck2cv

Tomorrow, I'm going to take both car and Trillium to an RV specialist a few miles from us to hear what he has to say. Before so, I will take a picture of the axle with the wheel off (as suggested earlier).

Franck, do you have that picture? I would appreciate a chance to have a look and see if I can help with understanding the situation. If not, a reminder of Roy's post - we're looking for something from this sort of perspective (although it would be nice if yours was a bit cleaner) or better still from a little lower position looking more directly at the axle where it mounts to the frame:

Remember, we're not assuming the axle is bad or saying to replace it as an experiment; the idea is just to objectively examine it as a likely source of the problem.

[MC1]

Ok Franck here is what you need to do.

Can Am is a Trillium dealer plus they are the most respected towing specialists you will ever find. They are also experts at setting up "cars" as TV's. Here is their web site. Can-Am RV Centre | #1 Airstream Dealer in Customer Satisfaction Worldwide | Your Full-Service RV Dealer

Give them a call and ask for Andy or Kirk. They have a reputation for helping folks over the phone (complimentary). If they can't help I'll eat my hat.

[mcbrew]

Franck, has anyone else towed the trailer with your car or any other vehicle since you bought it?

I have no idea what your experience level is with trailer towing... Just want to rule out the possibility that everything is working fine and you are just not used to how a trailer can impact a midsize car.

I mean no offense if you have lots of experience in this subject. I have run into a few people who think a "proper" setup means you can't tell there's a trailer back there.

[franck2cv]

Thanks again for you help. Although I'm pretty fed up, I still value your knowledge and dedication.

I removed a wheel to take the axle picture last night, here it is!
Suspension test.... Maybe this week end.

My expectation: ... based on my parents' experience. They used to tow an Eriba Puck (1180 lbs empty / 1550 lbs loaded) in France with a Renault Kangoo (1.6l gas engine - 2381 lbs / 3594 lbs).

Eriba Puck
RENAULT Kangoo 1.6 16V - 1997, 1998, 1999, 2000, 2001, 2002, 2003

Much lighter car, similar trailer mass. They only noticed the slower acceleration and MPG increase (15%). Nothing else. No impact on comfort, or chassis behavior ( under normal cruising & gentle driving)

So really.... I thought that the Mercedes being 1300 lbs heavier would not be affected. What would be nice, would be to try towing a similar trailer.

I'm going to call the RV people mentioned above (for the hat's sake!!) later today if work load allows.....

[mcbrew]

Your parents may have been impressed with the towing prowess of their car, but I an guarantee you that there is an impact on the comfort in the car.

I have towed with numerous Mercedes sedans, VWs, Toyotas, Hondas, and my Subaru. You will feel it every time the trailer goes over a bump. I tow a trailer multiple times a week. Just unhitched the 5x8 cargo trailer from my Outback. Every bump is felt as you described -- bump, bump, BUMP. Not so different with the car's axles, but when the trailer goes over a bump, it transmits a bigger jolt to the car.

I'm not saying that there isn't anything wrong... But I seriously doubt it is anything on the trailer other than maybe the weight distribution. It sounds like the issue is how you are feeling it in the car. It may have more to do with older shocks that aren't soaking up the oscillations well enough.

I am thinking that it would be a good idea to take someone one for the ride who tows with a similar sized car -- not a full size truck.

[honda03842]

Franck,

I haven't read the whole thread but my suggestion is that you borrow another RVer's vehicle and tow the trailer and see if you detect any difference. If not it's the trailer.

Simple quick and no cost. There must be a number of fiberglass RVers in Quebec.

[Roy in TO]

Franck, it looks like you need an axle to me. Look at this diagram: http://www.boattrailerparts.com/asse...orsionaxle.jpg
Pay particular attention to the Diamond that is shown on the various angles. In all cases the lines drawn through two opposing corners of the diamond should be plumb both vertical and horizontal. From your picture it looks like the spindle is 10 degrees below the horizontal of the diamond, but your diamond is rotated clockwise. That indicates to me that the rubber in the torsion axle is shot. Maybe someone that is proficient with drawing lines on pictures can show you what I mean. That is why Brian asked you for a picture taken straight on like in the diagram.

[Roy in TO]

Brian explains the angles here:
http://www.fiberglassrv.com/forums/f...html#post86611
And this post shows the rubber distorted in an old axle:
http://www.fiberglassrv.com/forums/f...tml#post342617
The axle should be centered in the axle tube, but you can see it rotated.

[Brian B-P]

Franck has done the same trailer / different tug; the same tug / different trailer combination would be informative, and was suggested earlier.

Now, about the actual issue with this trailer chassis...

Originally Posted by franck2cv

I removed a wheel to take the axle picture last night, here it is!

Excellent! Thanks

The attached photos - a detail from one of Franck's photos, and a version of the same that I have marked up - show the situation:
A Torflex axle has a fixed hollow square tube which runs across the trailer. Inside it, a solid square bar is held by a rubber rod jammed into the space between the bar and each corner of the tube. You can see the end of the inner bar coming through the arm which carries the hub.

When there is no load on the suspension, the corners of the inner bar should point straight up, down, forward, and rearward. In this case, the arm is lined up directly across the forward and rearward corners of the bar, so with no load the arm should sit horizontally: this is called a "zero start angle". The photo shows that even with no load, and even with the weight of the arm and hub tending to pull the arm down, it actually sits above horizontal. The rubber is permanently deformed.

How bad is this? We have certainly seen worse in this forum. Some of the travel, or ability of the suspension to absorb bumps, has been permanently lost. Is there enough left for reasonable ride and control (and Franck's expectations are just too high), or is there not enough? I don't have the personal experience to say, but the rubber of this axle is certainly degraded.

As the information from Dexter (in the last image below) shows, the axle should move the hub vertically (relative to the frame) 1.3" (33 mm) under the full rated load of the axle... and up to another inch (25 mm) under the most severe bump. In new conditions these suspensions move very little; can this suspension still move even close to this much? The roughly 10 degrees of deformation account for about a vertical inch taken even before the load is added.

I realize that the lines on my annotated version of the image are not very precise (the box isn't even square) - I just haven't had a chance to do this more carefully. I hope it's helpful even at this quality.

Edit note: I corrected a significant typo in my statement of the suspension travel under load - correct value shown above in bold

[gmw photos]

Yep, I agree Brian.
I see these torsion axles all the time. Most horse trailers ( at least the better ones ) have them. And I love pulling a trailer with a torsion axle. But..... I have never seen one that old, that was anything at all "like new", or even "like it should be". Anybody that thinks 20 to 30 year old suspension components are still functioning "as new", has most likely simply forgotten what new stuff really feels like. And that goes for tow vehiles or trailers.

I don't think anybody here would expect 20 to 30 year old rubber tires to be still good. Why would anyone assume that rubber suspension components would still be nicely elastic ? Ain't gonna happen.

Franck, the good news is, you are going to love the way your trailer tows when you get it all set up with a new, properly functioning axle. It will be a very different experience. And then you will have the benefit of seeing what happens when you go from one extreme to the other.

[Roy in TO]

Nice explanation Brian.
If and when Franck decides to replace his axle, I'd like to see the old axle cut in 1/2 like the Scamps I linked to earlier. Bet it looks worse.