Suspension related "donk"

[icklenutter]

Can anyone help me diagnose a noise?

I have a 2016 T6 that's had a "donk/clonk" noise on the suspension, but usually only noticed it on very uneven ground, like driving over a field, almost like when each wheel was moving independently, but no noise when going over a speed bump straight for instance. This made me think anti-roll bar or drop links. I couldn't find any play or obvious issues in them but replaced the drop links and anti-roll bar bushings anyway for good measure.

If anything the sound is now worse and happens on perfectly flat ground at seemingly random times, not related directly to bumps, not related to braking and I believe now only on the drivers side. There's also no feedback in steering wheel and I can waggle the steering wheel fine so dont think it's related to tie rods/steering rack.

I'm now thinking top mounts (although positive sound is coming from below), lower arm bushings or ball joints. Anyone have any insight or experience of something similar?

Here's a video of it, you can here it three times just going forwards and backwards.

 

[manfrotto]

What mileage has your van done? and is there any vibration etc at different speeds?

 

[Kind of Blue]

icklenutter , welcome to the T6 Forum. I have not viewed you video as yet

You might take your vehicle to a place where MOT take place and ask them to run the suspension stress test. The guy doing he test hopefully might allow you to see what is going on, in any case should be able to point out exactly what might be the culprit and what needs replacing. It may well be that some of the flexible joints are becoming a bit arthritic and need changing. You might consider a comprehensive renewal or just what needs doing but if you do one side it is probably expedient to do its matching pair on the other. Occasionality though a spring may have rotated slightly and just clunks. The guy doing the testing will point things out. At this time you may also may think about the suspension components particularly the dampers. Not the best from new if they have never been replaced might well be worth considering. Many aftermarket dampers are available and their are specialists fit and supply out lets represented on this forum. Many have their vapoured suspension manufacturers mine is KONI. Best of luck with sorting out your clunk, please let us know how you get on. this forum is a fabulous resorse with many knowledgable owners and some very bright minds indeed.

 

[icklenutter]

What mileage has your van done? and is there any vibration etc at different speeds?

160k. No vibrations that I’ve noticed.
A friend mentioned an unevenly worn CV joint, but I’m not convinced, it doesn’t seem to be connected to speed.
She also has a leaky lower crank gasket that I’m waiting to get sorted.

 

[DaveD]

160k. No vibrations that I’ve noticed.
A friend mentioned an unevenly worn CV joint, but I’m not convinced, it doesn’t seem to be connected to speed.
She also has a leaky lower crank gasket that I’m waiting to get sorted.

After watching the video my first thought was CV joint.

 

[BikerPa]

I would also inspect the drive shaft splines as they can give up, but otherwise it sounds very much like knackered CV joints to me as well

 

[icklenutter]

Thanks all, but problem solved! I hadn’t done one of the drop link nuts up quite enough, was only 1/8th turn to go. I must have had some pressure in the leg still when I first done it.
It was a very similar noise to the original sink, which turns out it was definitely the anti-roll bar bushings. So all fixed now, thanks for the advice.

 

[tomosllyr]

Just in case it is useful for anyone in future, I had a clonk which sounded very similar to yours in nature. Trip to CRS diagnosed a cracked bottom engine mount. Replaced and clonk has gone!

 

[CRS Performance]

Can anyone help me diagnose a noise?

I have a 2016 T6 that's had a "donk/clonk" noise on the suspension, but usually only noticed it on very uneven ground, like driving over a field, almost like when each wheel was moving independently, but no noise when going over a speed bump straight for instance. This made me think anti-roll bar or drop links. I couldn't find any play or obvious issues in them but replaced the drop links and anti-roll bar bushings anyway for good measure.

If anything the sound is now worse and happens on perfectly flat ground at seemingly random times, not related directly to bumps, not related to braking and I believe now only on the drivers side. There's also no feedback in steering wheel and I can waggle the steering wheel fine so dont think it's related to tie rods/steering rack.

I'm now thinking top mounts (although positive sound is coming from below), lower arm bushings or ball joints. Anyone have any insight or experience of something similar?

Here's a video of it, you can here it three times just going forwards and backwards.

These symptoms all point to drop links changing them to cheap after market will often be worse , Disconnect one side and drive the van , if the noise has gone buy 2 Lemforder drop links from Euro Car parts and swap the two front shocks left to right so that the drop links are mounting in to fresh holes on the damper. Cheap or Meyle drop links eat into the metal and they move causing the noise .

 

[AdamAsh]

Just in case it is useful for anyone in future, I had a clonk which sounded very similar to yours in nature. Trip to CRS diagnosed a cracked bottom engine mount. Replaced and clonk has gone!

Which engine mount please? Front or rear of the engine

 

[tomosllyr]

Which engine mount please? Front or rear of the engine

It was the front one