Thread: Major vibration towing with D4 (in 2 brand new disco 4's)

Hi Guys,

Looking for any input or experiences on what is a really sad situation.

We bought our first ever land rover, 2016 discovery 4 in Feb.
Love the car... however, when towing our 1.75 tonne boat at any speeds over 100 as soon as we hit an incline, we get a major vibration through the car.

We also get the vibration towing our 1.2-1.3 (loaded) tonne box trailer.
Not as bad but still a heavy vibration.

The vibration is through the whole car.
Changing gears or going into neutral does not affect the issue.
So it seems to be a driveline fault of some kind.

It is a SDV6 Dec build, Jan compliance.

Land rover have tried a new diff, new rear drive shafts and a wheel balance and it has made no difference.

Next step they want to try a "road force" balance, which apparently is a balance where they apply load to the tyres.

Today they brought another 2016 disco (late 2015 build) and we took the boat for a test drive, same issue.

Naturally they are pointing fingers at the trailer.

I'e had the trailer for 3 years and towed it behind no less than 3 other late model 4wd's and it tows like a dream.

Our last vehicle was a 2010 pajero and we did many thousand km's with the boat and box trailer with zero issues.

It has about 6-7% of the weight on the ball, dual axle mackay PU series trailer, only 7 yrs old and in very good condition, mechanical brakes, new bearings every 2-3 yrs, boat always secured with winch strap, tensioned chain at the front and ratchet straps at the rear. Boat is a haines hunter 1997 hull.
We always tow at highway speeds with the canopy all down an well secured.

We also load the boat up with probably 200-300kg of dive gear for trips (with a small increase in ball weight) and the problem is no different.

Our box trailer is a custom 6x4 single axle box trailer with steel frame aluminium panels. We load it very carefully to get a good 50-60kg ball weight (scuba tanks go at the front) and it has always towed perfectly.

I am in a very difficult position now, as with two new vehicles doing the same thing it seems to be a fundamental fault in the vehicle.

Any comments or insights would be greatly appreciated.
Is anyone in adelaide towing a similar weight boat that could possibly let me try towing their boat or vice versa?
Ideally an older build?

Maybe there is an issue with the late 2015 builds?

We are close to just getting rid of the vehicle and cutting our losses, which would be a shame, but my options are running out.

Cheers
James

Originally Posted by JamesAdelaide

I'm towing a different (similar weight) boat tomorrow and have a mate with MY13 who is going to tow mine, at least collect some more info to take to LR.

Good plan, differential diagnosis should be very helpful.

Scott