Dogbone insert startup rattle/noise

[Lehn]

I recently installed the Forge dogbone bush insert and have been very happy with it so far. Smoother downshifts when coming up to a red light and crispier upshifts. Only con is increased vibration planted in the cabin during hard acceleration but that was to be expected and it actually sounds pretty nice IMO.

Yesterday on startup I experienced a pretty loud metallic rattle, like a loose exhaust or something (happened during two startups). This morning I didn't hear a thing.

So, have anyone with a dogbone insert experienced an occasional rattle/noise during startup? I have only been driving the insert for 100km.

I will of course unmount the insert and check if the it's damaged and mount it again while being 100% sure it is fitted correct.

 

[Starry]

If there is an Increased vibration through the engine then There could be a rattle that you wouldn’t of heard with the standard Mount. The usual suspects will be the exhaust heat shield.

 

[Lehn]

If there is an Increased vibration through the engine then There could be a rattle that you wouldn’t of heard with the standard Mount. The usual suspects will be the exhaust heat shield.

It's not just a rattle from an exhaust shield or something like that. It's like the dogbone insert hitting the metal walls of the bushing with great force. The strange part is that it was gone this morning. That's why I'll have to check if somehow the insert is loose or deformed (I torqued it to the suggested 135Nm).

 

[Starry]

Ah, I see, so it’s a proper banging and really a rattle. As you've already said, have a look at the mount and go from there.

 

[Lehn]

So after some extensive youtubing and google image searching I have decided to modify the Forge insert (and regretting I didn't just order the 034Motorsport version from the start, but I couldn't justify the £30 postage to Denmark for something that looked so similar for the unknown eye).

034Motorsport have made this fantastic video showing their insert in action. If you look at the top section it's clear that the insert moves a little upwards under WOT - so it'll most certainly make the same upward motion under startup when the engine shakes. 034Motorsport have taken this into account by not having any material on the insert that will prevent this upward motion. By taking a closer look at the Forge insert it's clear that any upward movement will be prevented by the insert and possibly be heard as the rattle/knocking during startup as I'm talking about. Only time will tell.

 

[Lehn]

Just for others to know, this did the trick. I must admit that I will change the Forge version to a 034motorsport version in the future because of this design fail.

 

[RS200Z]

Thanks for taking the time to share your findings. Guess the devil are in the details.

 

[Leevr]

034 dogbone shows two versions. Is there any way other than getting under the car to ascertain which version will fit. This is the illustration used. I've got a 2015 S3 manual.

 

[Lehn]

034 dogbone shows two versions. Is there any way other than getting under the car to ascertain which version will fit. This is the illustration used. I've got a 2015 S3 manual.
View attachment 179251

No, or, there is a smart way to do it (can't remember who posted it in here). Take a piece of cardboard, grab your phone and start recording, slide the phone under the car on the cardboard and watch the video afterwards

 

[Sean6211]

If I recall correctly, you still need to remove the lower pan cover as it obstructs the view of the mount.

 

[Lehn]

Take a look here guys: