Bilstein: knocking noise from the front suspension

[cpitts]

My GT-B's just turned 100K and I have this rattle problem from what sounds like the drivers side suspension.

Fairly easy to replicate with left/right turning at crawling pace.

Have tested:
- slow turn in circle to right & left: No can rattle (CV joints)
- wheels don't wobble
- strut tower brace is still bolted down tightly to the struts (all 6 nuts tight)
- bouncing each corner of the car doesn't show excessive or sustained bound or rebound

It sounds like a rattle/clunk that only comes when the car shifts weight from one side to the other. I'm thinking crushed/popped out gromet/bush, snapped end-link (rear sway is stiffer Whiteline item), maybe engine mount?

Yet to get it looked at but sounds like typical suspension shops could be a waste of time.

Was hoping some more detailed analysis but sounds like everyone's getting the same bad/no advice.

Any new thoughts?

[Dropz]

have you checked the strut insert bolts? The 17mm in the centre. Take the little dust cap off and see fi thats tight.

[cpitts]

Further to the post above, I've had the car checked over by a Subaru specialist and all visible suspension items seemed to be in tact and all bolts were tightened up with a rattle gun.

Suspected failure is with the Strut Top itself, not the struts, bushes, etc. Turns out this is a very common failing with the 05+ Subaru's. I'll get it attended to as part of my 100K service I think.

Has anyone else been pointed at Strut tops?

[RJ_]

Yes. My strut tops were also noisy. Replaced with OEM parts and now all good. RJ

[bass_straitener]

I'm experiencing the same knocking sound as others in this thread.

Having had the car looked at by a professional and speaking with others on other forums etc I've come to the conclusion that the OE Bilstein struts are stuffed. Everything else suspension wise is fine and has been checked thoroughly.

The next step I've decided is to source replacement struts. Any ideas on what a good replacement would be, matched to the STI springs.

At this stage I'm not considering coilovers as I reckon this would mostly be for 'wank factor' than any actual performance gains on the road. I'm not planning to track the car at anytime soon. Though I'm happy to be convinced coilovers are the way to go.

[dilmah22]

Been a while since I last posted, so a bit of an update;

As you will have seen, I replaced my OEM Bilsteins with brand new Bilsteins, and even changed the springs to Tien S-Tech's from PHAT_GT, which are specially designed for the Australian delivered Bilsteins (which are apparently slightly different to the JDM ones).
New tires & Alignment
New brake rotors and pads & fluid (fixed the vibration issue i was having under braking - perfect now)

The issue still remains.

Had a workshop check over my car at my last service, they showed me while the car was on the hoist, the springs are rubbing against the base of the shocks. You can see the wear and tare on the green coatings on the Tien springs where they're rubbing. The rubber (or whatever they're made out of) mouldings from the original bilstein springs are correctly installed at the bottom of the tein springs, but don't seem to go far enough up & around the springs to insulate it from the metal shock surrounds and they suspect the springs are actually moving around inside the shock when the car is subjected to lateral loads.

I might try putting an old rag around the bottom of the spring one day and drive around a corner and see if it stops the problem.

I've heard there's polyurethane "tape" or mouldings that you can get to put around springs for this very purpose. Similar to the black ones currently on the springs, but just cut to whatever length you require.

Like you, I didn't really want to buy coilovers either.

[bass_straitener]

I have no movement of the STI springs on the shocks. Even with no load with the wheel hanging so I don't think that's an issue.
I've been told it's more likely to be the shock itself. And it's a common replacement item at Subaru service centres.

I won't be buying a replacment set of OE struts from the sydney seller as a I believe these parts could be upto 5 years old and I don't consider them to be as good as new if left on the shelf for 5 years. Seals etc can deteriorate whilst in storage. Plus OE Bilstein failure rates are high and can occur anywhere between 20K to 80K kilometres from reading the forums. So they don't see too reliable.

All other suspension bits have been tightened and greased etc so the shock internals seem to be the only thing remaining.

I'll go over it again myself this weekend and then start investigating alternatives.

[bass_straitener]

OK, I've had a another look at the suspension over the weekend and could find nothing wrong with any component that could be blamed for the knocking sound. So I'm back thinking it's the shocks.

I've also made inquiries and taken opinions from various people and here's how I'm going to progress to hopefully fix this issue.

I'm having Trutrack Suspension in North Melbourne rebuild my existing shocks. I spoke to Ralph there and he commented that he'd seen a lot of Liberties with this problem and can be rectified with a rebuild as the top of the shock is the problem. He also commented that the original setup is pretty basic for the OEM build. These guys come highly recommended so I'm giving them a crack.

The shocks will be rebuilt and revalved to suit the STI springs and dyno tested.

The entire front end will again be checked over with a 4 wheel alignment and dynamic balance.

Hopefully this will solve this issue.

[dilmah22]

Awesome work! Let us know how it goes and what they actually find and end up fixing.
Also, if possible, let me know how much it costs (just a ballpark figure will do), feel free to PM me on this if you prefer. I'd like to get this fixed sometime - it still annoys me to no end..

[Tradewind]

Interesting

I am thinking, do the shocks have to be necessarily bilstein??

I could use KYB or something similarly reliable

[msgofast]

Wow so many people with this problem and so many shops ripping you

The issues are with most inverted shocks, the STI rears are very common.

The reason they do it is the grease they use, the shafts bind up, the grease is like plasticine, they suffer from sticksion , the fix is easy!

Pull it apart and remove old grease and pack it with castrol LMM grease, or the fix i do now is drill and fit a grease nipple and pump the struts body between the bearings with LMM grease, ride will be smoother, noise will go.

The noise gets so bad you would think the strut is going to fall out!

[Dropz]

I'd heard a rumor of fitting grease nipples but never heard of someone doing it in practice. Periodic greasing should extend shocker life hugely.

[wannawagon]

I suppose i have only one thing to add, car has done it (front RHS) since we have owned it at 9 months of age and about 10000 km on clock.

It is worse in hot/dry weather and seems to go away if rubber bushes etc and strut top are hosed with water (i used to do this on an old pajero with the "shockie noise".

I have just today had it on the hoist with a mechanic (neighbour) and all we can find is LCA bushes marginally sus (but they wouldnt have been 3 years and 40000 km ago).

My thoughts its in the strut but my neighbour tightened the rack mounts (note RHS is different to LHS) and it could have made a marginal change.

Its interesting that we all (including me) think its RHS not LHS, so it would be unusual for it to be struts (as they should have same bushes/valves etc). But my gut feeling its in the strut as well. even though logically it shouldnt be different LHS to RHS, especially when it is fair to say that the LHS normally hits rougher road at the kerb and shoulders etc and should wear quicker.

Is the bearing in the strut mount (top of tower) or somehow in the strut? have played with other cars and its in the strut mount - just trying to workout where the grease nipple is placed etc as would be prepared to try it. any chance of a photo?.

Cheers Matt

[msgofast]

No pics sorry, 3-4" down from the top is where it needs to go.

Next one i do i will take some pics

[wannawagon]

Thanks for that, would like to see photo so I know what works., any idea when the next one is likely? I take it the nipple goes just below the "spring mount" on the strut, above the knuckle mount?.

how much grease is used? Is the shockie under pressure at that point (when loaded)? how far up does the piston travel? wouldnt want to put nipple too far down or it would fowl piston?

what about "drilube spray" or something on the shockie shaft?. (i suppose it would work for a short while only).

when the hole is drilled for the nipple will the "swarf" from the drill be an issue, or does it need to be pulled apart to clean the old grease (and new swarf) out.

I take it its done to both sides.

Any thoughts why its RHS mainly, not both? assume the grease would be the same both sides?

also apologies, i take it that the bearing refered to in the earlier post is the "slide" type and not the stearing "swivel" type.

cheers, Matt