Re: Yo Josh, I may have found cause for knock! (archive)

Klaus...
Make sure to diagnose this problem completely before doing any repairs. The steering components on these cars have a nasty habit of taking other components out with them when they fail.
It sounds to me like you have multiple problems in your front end. I went through this a few years ago and ended up taking things apart and putting them back together way too many times.
Start by crawling under the car and have someone give the steering wheel hard left/rights. If it is as bad as it sounds you will be able to see and hear the trouble quickly.
My suspicion is that you have a tear in a steering rack bellow. This allows grit to enter and quickly destroys the ball and socket inner tie rod. As this fails, it puts unusual angular stress on the steering rack, which in turn, wears the rack bushings quickly.
If you see/ hear the problem inside the bellows, it is probably cracked, torn or the clamp is gone. If this is the case, cut it off with a knife. Do the left/right thing again with an assistant, and see what you see. If it is just the ball and socket, you are lucky. Grab the socket section firmly, and push up/down and feel for play. If there is any play, you are also looking at a steering rack. All this starts with a tear in the rubber bellows.
Also, if you need repairs, install an anti shimmy kit from Bavarian Autosport. It will be the best twenty bucks you ever spent on the car.
This is not an impossible driveway repair. A rack, or inner tie rod end can be changed in an afternoon.
The key to this is do it correctly and completely the first time through. If you do this repair you will absolutely need an alignment afterwards.

Edward

I went underneath the car today thinking this can't be that bad. I have to troubleshoot electrical circuits which are much worse!

Turns out that I have a play on the rod that turns the wheels, the rods that have some rubber shield about 6 inches in lenght protecting them; tie rod maybe? In the Hayne's manual for the 320i, it's the predominant rod with the rubber sheild that looks like an accordian on Fig 11.3 page 172. Futhermore, there's play only on the side I experience the knocks and no play on the other side.

This might explain the knocks during breaking, but what explains the knock over bumps? That I still have to figure out.

Klaus, 81 e21 iS
In Search of why e21 shimmer

Follow Ups:

[ Follow Ups ] [ 3-series (E21) Message Board ] [ Msg. Board FAQ ]

Questions, comments, or problems, please visit the Roadfly help desk.