From reading various forums and blog posts there were various suggestions for the knocking sound which could be the drop links, coffin arms or top mounts, all of which look to be the original 1998 vintage parts still in place.
|Porsche 996 Front Suspension Knocking When Warm|
During the free healthcheck at Porsche Centre Tonbridge it was noted that there was slight play in the Track rod ends/Tie Rods on one side so I decided that I would replace all both the track rod ends and inner tie rod joints to resolve the problem.
|Worn track rod end Porsche 996|
On removal from the car it was obvious why the steering had been so uneven and pulling side to side as one inner tie rod was completely corroded in place with the ball joint unable to move. The other was the one with play in it and showed slight movement. The rubber boots of track rod ends were both perished and the grease lost as well as the bearing being very loose.
I purchased brand new TRW parts to replace both track rod ends and inner tie rods which came to a total of £90. Compared to the £90 for one track rod end for my Porsche 944 this seemed a bargain!
After replacing the track rod ends and tie rods on both sides the transformation is amazing! The car no longer feels like it's wallowing all over the road, the steering is precise and untroubled by rough roads or bumps.