Looking for help. I was wondering with the members experience they may have come across the following.
Recently I purchased a Forester XT and when towing a small two berth dog trailer the car has intermittent vibrations. I have towed the trailer with two other vehicles a Hyundai Elantra lift back and with my previous car a Subaru
Liberty wagon with out any issues.
The vibration comes and goes, very inconsistent but can be quite violent at times. I find if you vary your speed when the vibration occurs, the vibration disappears for a period then reappears. When my wife first brought it to my attention I thought little of it till I
test drove the car.
Initially the vibration came in around the 80klm mark and got progressively worst as the speeds increased. I have completed the following checks
Removed
the springs & axel to ensure no damage
Fitted new bearings to both wheels (one bearing was slightly worn)
Tyres checked and re balanced, ran at different pressures 24 to 30 psi
Car has been checked by Subaru, no faults
At 500klm the car was re aligned, out 4 deg rear & 2 deg front (no change to trailer behaviour)
Rotated the hitch (turned upside down to lower ball height) & changed ball to a ball from my previous car (no noticeable vibration until reaching highway speeds)
Replaced coupling with a new coupling with an adjuster (slightly better, not as violent vibration)
Recently fitted a roof pod from my car on top of the Trailer for aerodynamics (no change)
Not sure where to go next, I am wondering if this is a turbulence issue. The difference between the Forester and
Liberty are
Forester
Liberty
Length 4560 4720
Width 1795 1730
Height 1700 1470
Ground clearance 225 150
Weight 1510 1395
The Forester has a small rear wing as did the
Liberty, another family had a similar issue when they bought a Nissan Xtrail but chose to sell the trailer and replace it with a larger trailer. An expense I 'm not comfortable with. I have spoken to the manufacturer of the trailer and they have not heard of the above, we went thru a range of solutions which are mentioned above.
Trailer specs
2 Bays @ 1167mm x 900mm
length: 3.30M x Width: 1.70M x Height: 1.50M
Empty weight: 280kgs approx
Is there any one who may be able to shed some light on the subject?