Front suspension clunk, during weight transfer
 

My car has developed a 'Clunk' from the front suspension, initially i thought it was the droplinks (end links) but i have removed 1 (Drivers side), but the clunk still exists.

It seems to happen during turning, the steering wheel does NOT have to be moving, it could be in a fixed position (turned) or during turning.
It also happens when the weight of the car is shifting ON/OFF of the front end i.e. during braking/accelerating. It is more pronounced when turning right, although still happens when turning left.

Im slightly concerned because it started as a small(er) clunk and has got worse. i first noticed it when failing right handed drifts and spinning out when the weight shifts dramatically one way to the other.

Are there any known problem areas i should check?

could be ball joint, bushings in the a-arms or lower control arms
Loose shock bolts, blown shock ...lots of stuff

Get it up on a rack and start looking to see what is loose or doing something it isn't supposed too ;-)

So it could be any part failing, i was just hoping there was an area prone to failure. But thanks for your help, il update my findings in here.

factory or aftermarket sway bars?

If aftermarket, try greasing the inside of the bushings, between the bar and the bushing.

All stock suspension, besides Lowering Springs

I have had the same problem with failure of 2 different components, an end-link and a sway bar bracket, so i would check those first. That being said, just based on my experience, I think end links are the most likely to give you this issue, and it's not always easy to localized a "clunk", so I would remove both and see what happens

Remember, for diagnosing problems, you can just completely remove the end links on both sides, and if the problem perists, you know for sure it is not a problem with either the links OR the sway bar, as it's not connected to anything!

Thanks for the input, some searching did point to endlinks being a possible cause, but given the amount of corrsion on them, theyre gonna need to be grinded off. I will get round to it tomorrow/weekend, and see what i find, will check the swaybar region as well.

I've been having this exact same issue for close to 30,000 miles and a couple years now... It's gradually gotten worse but still not to the point where I'm worried about it, but it is definitely highly annoying. The car still feels quite stable in turns(I had another rx8 before this and they handle similarly)<br />
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I searched and searched when I got the car(god knows how many miles before I had mine that it went on), and there didn't seem to be any threads describing my particular issue. There were a lot of threads about a TSB regarding lug nut torque(something like 108ft/lbs recommended?), and end-links as mentioned in this thread already. The first thing I did when I heard this was tighten down all the bolts regarding suspension components, and attempt a drive with the end link(one of them) disconnected. I'm really curious to see if endlinks end up being your problem, and am wondering if I shouldn't try disconnecting BOTH of mine at the same time to see if I could have just disconnected the wrong one all that time ago.

My most recent discovery is that it seems to only happen once per load transfer - i.e. long right handed turn to a straight, if it clunks when the weight transfers left(as car turns right), it won't clunk even when I straighten out on the car on the straightaway until weight transfers back to the right(as car turns left).

I replaced both endlinks, still the same issue. i haven't had the time since then to investigate further. My mechanic couldn't find anything but he told me that the wishbones, and control arms are secure.

I'm not sure if my issue is the same or not, but i do get a clunk going left now.. didn't originally, but as its got worse it has.

I have suspicions about the damper, but cant find any internet info with people having clunks associated with damper failure (RX8).

It could easily be a shock....I would expect it to be leaking though...something that your mechanic should have picked up
There really sn't that many options......

Are the cross member bolts tight?

It dose this with the car sitting still? I'd look at the stearing I'm not to familure with the stearing on the 8 but check your tie rods and anything connected to them. Most likely I'm wrong as you should have play or shaking from such a thing but I agree it sounds more like a strut but even then you shoud feal it.

I have had multiple looks at the damper itself, its most definitely not leaking, does the bush act as a seal as well? Only people that have f*cked around with the oem damper would know i'd guess.
I have yanked on it before but it has made no clunk. But then again my mechanic told me to replicate the noise, he had to use a pretty high amount of force pushing down on the front right.

I will check the crossmember, although as far as i'm aware, it has never been tampered with, especially during my ownership (2 1/2 years).


Apparently so, although ive never made it clunk whilst stationary, see my reply to dannobre.

I'm not sure in regards to feel, i have got the impression before i have felt it through the steering & maybe the pedals but it could be placebo. Its definitely not promenant enough to give a definite answer. i realise that, that is very little help.

This weekend im gonna take the bumper off to replace some corroded bolts and that should give me a better view of everything, crossmember, tie rods (although im sure ive checked), and everything else. taking the damper out may just seem like a bit too much effort, but if i must... eventually il have to.

BTW, mods and maintenance that may/may not affect this:
Lowering springs
Polyurethane engine mounts
3mm spacers

Running OEM shocks with lowering springs makes it even more likely to be a shock.....

I would pull the shock...remove the spring.....and then you will be able to move the suspension components easily on the car...ball joints and bushings will be easier to diagnose.

With the spring off it will be easy to tell if the shock is blown...it should go in and out smoothly with constant pressure. It shouldn't clunk or be really easy to push up and down

You will need a spring compressor and need to know how to use it ;-)

When I removed my front lower control arms the rear caster control bushing rubber was cracked pretty badly. I could see it eventually failing which would allow the rear of the control arm move up and down which could cause clunking, especially with the front lifting and diving under accel and braking. Mine would clunk in the front after reversing then pulling forward. Haven't re-assembled my front end yet so I can't say if fixing that bushing fixed my clunk. It's kinda hard to see as it's recessed into a pocket in the subframe.
It's the unlabeled doughnut shaped bushing in the diagram below
Attachment 221149

I have a hard time believing that the damper assembly could be making an intermittent clunk. Usually noises from the damper in a wishbone suspension are high to mid frequency persistent rattles.

thanks for pointing that out, the one thats not labelled. i had the rear wishbone bushing fail on my previous E46, but that was a known failure. i will check it out. How much of a b*stard is it to fix? i asume it needs to be pressed in?

It's a bit of a bastard. The front lower control arm bolt tends to seize to the bushing sleeve. If it's bad enough you may have to cut the bolt off then you may have to replace the front bushing too. The lower ball joint can also stick in the hub which can pull the steel sleeve that the ball joint inserts into out; Mazda says if that happens you need a new hub.
You can remove the bushing without a press with careful application of a torch and a hack saw, but if you want to put an OEM rubber bushing back in you'll need a press. Be sure to refer to the service manual as the bushing requires a specific orientation.

Solved**
 

Thanks for the help guys,
I thoroughly checked over the front this weekend, including dampers, arms, crossmember etc. I discovered it was my RH engine mount that had come loose and i believe it was rocking backwards and forwards. Anyone know the torque specs for this? i tightened to 55nm.

Oh man! too late.

I was going to tell you to check that as it was my bet. The engine mount.

When I bought my car I thought it was the same thing, RH engine mount(which looked like it had been rocking back and forth and looked like those metallic nubs that kind of keep it square were badly worn), but I still have the pop/clunk even after replacing that - although I didn't have a torque wrench at the time.

Might have to look into torquing it down, but I'm beginning to be concerned for the health of the bushings on the LCAs - which I believe if you buy a brand new one, comes with new bushings as well.

Definitely torque it down, I think initially I tightened them to around 40nm, and it still got loose. maybe 60-70nm once I had discovered it was the engine mount was moving.