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

[franck2cv]

Hi ,

Just found our ideal Trailer!!!... (1977 Trillium 1300) More on that soon.
Right now, I'm preoccupied with very bothering car behavior following a short test drive.

Basically, our car (1995 Mercedes E320 Wagon) is badly shaken by the trailer every time the trailer goes over a road imperfection. Everything is tight as it should. When I hitched up the Trillium, I noticed that the front stabilizers were quite low with a regular ball mount (C). So, I changed the ball mount to rise the Hitch height. That caused the trailer to tilt backward (A). I suppose the Ideal set-up would be horizontal ( ?
Could this be the reason the car is shaken so badly?

I took the car to a newly asphalted stretch of road and tried different things such as: harder acceleration, harsh swerving and braking. No problem. The car is fine and smooth as a flying carpet on its own. The rear Suspension is Hydro pneumatic and self adjust according to load. No issue here, it works at it should. The Trillium suspension seems fine too (clearance / travel / elasticity).

Thank you for your input. I'm a total novice with experience only limited to towing small utility trailers.

Franck

[MC1]

You are right Frank the trailer needs to be level or slightly nose down. Nose up can cause a variety of issues.

Do you have the right size ball for the coupler?

Can you post a pic of your connection please?

[Raz]

With the trailer disconnected, check to see how much play there is between the draw bar and the receiver. Up and down play can translate into quite a vibration with a very distinctive thud in the tow vehicle. Some folks shim the draw bar while others use various anti-rattle devices. Raz

[Roy in TO]

Might be a weight thing too, it's a balancing act.
Ideally you are looking to have 60% in front of trailer wheel, 40% behind while trying to keep the tongue weight at 10-15% of total trailer weight.

Not sure about the hydro pneumatic suspension, is it on all the time (fully automatic) or a set it and leave it (semi automatic).

Could also be the axle on the Trillium. If it needs replacing it will be ovely stiff and have no suspension to speak of. Or is the extra weight too much for your older suspension on the wagon? You can test that with different trailers.

[franck2cv]

Originally Posted by MC1

You are right Frank the trailer needs to be level or slightly nose down. Nose up can cause a variety of issues.

Do you have the right size ball for the coupler?

Can you post a pic of your connection please?

Ball size: 2" as per couple spec (stamped on)
By connection, do you mean the coupler, the hitch or both?
I could take some later today.

[franck2cv]

Originally Posted by P. Raz

With the trailer disconnected, check to see how much play there is between the draw bar and the receiver. Up and down play can translate into quite a vibration with a very distinctive thud in the tow vehicle. Some folks shim the draw bar while others use various anti-rattle devices. Raz

There's a bit of play indeed. There's a loud clunk every so often.
Once I will have found the ideal ball mount I will shim it or used the grinded weld bead technique to make it a tight fit.

[gmw photos]

When was the last time the axle was replaced on this 1977 trailer ?

[franck2cv]

Originally Posted by Roy in TO

Might be a weight thing too, it's a balancing act.
Ideally you are looking to have 60% in front of trailer wheel, 40% behind while trying to keep the tongue weight at 10-15% of total trailer weight.

Not sure about the hydro pneumatic suspension, is it on all the time (fully automatic) or a set it and leave it (semi automatic).

Could also be the axle on the Trillium. If it needs replacing it will be ovely stiff and have no suspension to speak of. Or is the extra weight too much for your older suspension on the wagon? You can test that with different trailers.

Suspension: Automatic. Basically, there's a lever, activated by the rear suspension. More pressure is sent in the spheres when required.
The whole thing was overhauled by the previous owner. I drove it last year with a full load, probably exceeding slightly the payload. It behaved superbly with no difference in road handling or comfort. Back in the 90's I often saw massive trailers towed by exact same wagons (in Europe!). The Trillium really seems like a small task.

Thanks for the info regarding weight ratio. I shall weight it as well to know the exact figure.

Trailer axle: I have no idea if the unit is original or, if it has been replaced at some point. Do we know the normal road clearance ? I'm assuming a tired axle would sag with little travel left? Our Trillium seems to have a healthy axle : Good ground clearance and, when you come in and out, you can clearly feel the suspension travel. (a 'XXL' friend had a look inside last night and the trailer really sprang up when he stepped out! )

[cpaharley2008]

There are always these for anti-rattles
Anti-Rattle Hitch Accessories | etrailer.com

[MC1]

Originally Posted by franck2cv

By connection, do you mean the coupler, the hitch or both?
I could take some later today.

Yes, a side view of the connection and whole combination would be great. Thnxs Franck

[Roy in TO]

Originally Posted by franck2cv

Trailer axle: I have no idea if the unit is original or, if it has been replaced at some point. Do we know the normal road clearance ? I'm assuming a tired axle would sag with little travel left? Our Trillium seems to have a healthy axle : Good ground clearance and, when you come in and out, you can clearly feel the suspension travel. (a 'XXL' friend had a look inside last night and the trailer really sprang up when he stepped out! )

The spindle should have about a 3" range of motion from no load to shock load. Some of the movement may have been due to tire flex. Which gets me to thinking, Do you have Trailer tires on the trailer and are they inflated properly?

Does anybody remember where the video was of the trailer on a treadmill that they move the weights around on the trailer? It was a great visual example.

[Roy in TO]

Found it:
Bailey of Bristol - Caravan Stability Studies

[franck2cv]

Thanks you guys

As we're planning to go camping and inaugurate our little egg, I'd better get this understood and fixed for Saturday!

My to do list:

- Side view connection picture
- Tire type + brand
- Tire pressure
- Tongue weight
- Road clearance Pictures:
Off load + under trailer normal weight.
Without my XXL friend, any trick available to simulate a load & flex the axle ?

[Roy in TO]

Originally Posted by franck2cv

Without my XXL friend, any trick available to simulate a load & flex the axle ?

Take off hub cap, measure center of spindle to point on body.
Jack up one side of trailer and repeat measurement.
Lower trailer, invite 3 friends over, X O X, and have them jump in unison on same side. Measure lowest spot of same point on body to spindle.

Difference in last 2 measurements is range of motion. Should be about 3".
Post results for all to see.
You can watch the tire flex, but don't measure it as that is not what you are looking for.

[gmw photos]

The reason I ask about the age of the axle is, if it's original, it's in need of replacement.
When diagnosing and fixing problems it's always best to get all known normal consumable items up to snuff first, and then fine tune out any remaining issues. To do so otherwise is simply covering up one problem with a "solution" that may be less than ideal.
Get the basic foundation right, then build from there.

[Francesca Knowles]

I disagree that the axle should automatically be replaced.

The original Rub-R-Ride on my 1978 4500 is in very good shape, and I myself have put over forty thousand miles on it-some of that over rough roads- since I got the trailer in 2005. Who knows how many miles it had up to that point...

I think the problems described in the opening post are likely ALL due to the too-high ball. Get that puppy level, take it out for a spin, and report back.

Francesca

[David Tilston]

I replaced the axle on my 1978 4500, based on exactly the same, "it is over 30 years old" rational. In retrospect, it did not need to be replaced, but I needed more capacity then the stock 2000 lbs. anyway.

[franck2cv]

Well obviously, the axle replacement will be considered if required.
But for now, I'm going to do my homework & follow Roy's recipe.
More soon..... I'm recruiting heavy friends!! lol

Franck

[Roy in TO]

Just hum the Hollies tune: He ain't heavy - he's my brother ... as you do it

[Raz]

Originally Posted by franck2cv

Well obviously, the axle replacement will be considered if required.
But for now, I'm going to do my homework & follow Roy's recipe.
More soon..... I'm recruiting heavy friends!! lol

Franck

Buy some beer, they'll show up. Raz