RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

So i think i have play in my steering rack, hear a knocking the wiggling the wheel, its not joints etc.

I read a lot about loose mounting bolts, i can only see the passenger side one, its not moving.

The drivers side has two bolts, one top, one bottom.
Wishing to check the top one first, i cant see it anywhere, it must be around the brake fluid reservoir?

Any advise appreciated.

I wonder if this knocking is what i thought was suspension related since i purchased the car in 2010, with new shock fitted, etc, it never went away..... fingers crossed.

Have read it seems to be a fairly common issue that the Steering rack bolts become loose.. although that does seem odd to me.

As far as I'm aware, there are 3x steering rack bolts - two on top, one underneath:
Think one is located underneath the ECU, under the plenum chamber / skuttle panel

Have you replaced or checked the front Drop links and front ARB bushes?

Also, check the upper control arms , and Top mounts at the same time?

I reckon any of those could potentially also cause the dreaded knocking..

Actually, whilst on the topic of the Steering Rack...

Wonder how many owners renew / flush their Steering rack fluid?

I checked mine last month..

what can I say .. it was putrid / rank in both look + smell - never been changed

Made the mistake years ago with another vag car - left the old PS Fluid (read overlooked) in there for ~20years...

huh.

Surprise. Surprise.

The Steering Rack eventually developed a leak..

Had to replace the entire Steering Rack on the driveway - on my back. Nice.

Thats now on my list to do, thank you.

Where did you drain it?

So i found the top bolts, one is hidden under the brake vacuum booster. Can just seeit if you look with a torch from the drivers side, had to blow the area out with an air line and there it was.

And its Tight! Both top ones are, and dont move when rocking the wheel and hearing the noise.

So it's something else.

Replaced rod ends and can feel the inners have no play.

Sound is coming from the rack itself, i am 90% sure now. So seeing this in the workshop manual. Has anyone had their rack adjusted for backlash play?
Easy to access from below, i am wondering?

Well. I didn't know the RS Steering rack was adjustable.. that's interesting

Here's a close-up of that rack adjusting screw:
Let us know if any rack adjustments cures your knocking..

In terms of PS Fluid renew / flush, never found any drain plug as such - so you can either disconnect the hose from the bottom of the PS reservoir to drain - or syphon out all the old fluid, which is what I usually do.

Give the reservoir a good clean, and fill with new fluid. Then, purge the rack of any air / get rid of any air-locks by turning the wheels side to side - with the reservoir cap off and engine off. (easier to do when wheels are off the ground).

Do this a couple of times over a few years (or as you determine) .. to flush the system .. and you'll notice the difference in steering feel.

Thanks, i will have a go at adjustment over the weekend, having just replaced all the front suspension, its certainly the rack and driving yesteday i was reminided it's worse when cold.
May make sense if the rack/fluid warms up, its also right above the exhaust manifold so will get some heat off that, maybe something expands, who knows.

Not sure how easy it will be to access the adjuster, cant find any examples of anyone doing it on the B7 RS4.

I have done a write up here on how to flush the fluid out:
viewtopic.php?f=121&t=131868&start=30#p917323

Thats great, thank you.

Nice easy maintenance job and certainly due at 18 years old now.

lugars4 wrote: ↑

Fri Apr 19, 2024 11:10 am

Thats great, thank you.

Nice easy maintenance job and certainly due at 18 years old now.

Did you fix it? I think I may have the same problem as you. I’ve ordered new rack bolts to replace anyway but this might be the problem if the new bolts don’t cure the knock

I dont beleive the rack is knocking. Looking at DRC re-charge now.

The rack bolts were tight.

The knock i feel / hear rocking the wheel with engine off, goes away with engine running. But it was a concern. However our other VW car appears to do the same, so maybe a knock when rocking the wheel is normal without the power steering running?