Low speed front suspension clunk when braking/accelerating turning: shock absorbers?

[Bruno_300TE]

Hi everybody
I have been taking care of my car's (1992 300TE 148kmiles) most problems, except this one:
At low speed, especially when the weather is hot and after some driving I can hear annoying clunks from the front end. It mainly happens when braking, accelerating and turning. In the last 15kmiles the car had new control arms, tie rods, drag links, idler arm bushing, shocks (Bilsteins), shock mounts, wheel bearings, tires - basically a whole new front end.
Last night I had the car jacked up. When I twisted the wheel and consequently the whole steering mechanism I heard the noise again. It is coming from the shock absorbers. When I loosened the mounting nut on top of the shock mounts the noise was gone. As I understand the shock absorbers turn internally to accommodate to different wheel positions. They don't smoothingly but respond with repeated clunks, as if something had to brake loose again and again to allow the shock to turn.
Are my shocks broken? Is this a common problem? I have not read of anything similar on the forum.
As always your sensible comments are very welcome, Bruno

[radunegru]

I am havin the same noise on the rigt side ( pass side), same simptoms ...hot wheather,...etc. Stilll don,t know the cause? Mine does on violent braking from 15mph to 0mph.

[yal]

Maybe the shock mounts wern't mounted properly or bolted with the correct torque. Just a guess.
How about the bolts that connect the shock to the carrier how are those?

[Bruno_300TE]

Well, after thinking it over again, reading other posts etc: I bet it's the ball joints. I'll apply some oil to them with a syringe in order to see whether there is any change in noise. The only thing I wonder: How could they fail after only about 15kmiles?
Bruno

PS I followed the torque specs when installing shocks and mounts.

[radunegru]

I have new ball joints so in my case this can't be the issue.

[Bruno_300TE]

Yes, mine aren't old either. I applied some oil to them with a syringe - but the noise did not change. So I rule them out for the moment. Rather, I ordered a new swaybar (the old one is rusted) with new bushings. The bushings are fairly new but I guess they can wear out quickly on an worn sway bar.
Bruno

[Bruno_300TE]

Hi everybody
Car is a 1992 300TE with 150 kmiles. It got a whole suspension rebuild aboout 15kmiles ago. Since the weather got warmer I have a clunk after a while of driving (warm suspension components) when coning to a Stop, when accelerating from a stop, at slow turns.
I redid:
- strut mounts (new)
- shock absorber (tested with new ones)
- ball joints (new)
- sway bar and bushings (new)
- degrease control arm mounts and put new eccentric bolts, torqued to 150Nm instead of 120 Nm (following advice given in a tech bulletin)
- wheel bearings (new)
- idler arm bushing (new)
Nothing helped... My latest theory is as follows: (1) The problem is the eccentric bolts - they are not tight enough. (2) the special washer of the eccentric bolt will only go as far as the groove allows in the bolt, even when substantial torque is applied.
So, I have to grind the washer slightly so that it will go a little bit further on the bolt in order to make it tighter.
Can anyone of you comment on this idea, or do you have another suggestion, something I overlooked? How about the mounting bracket of the sway bar? They are not cracked - could they be worn somehow?
Many thanks and have a good time!
Bruno

[radunegru]

Thanks for your great input.
Also I am trying someting new today. I had this annoying noise on both sides last year. But i remember that due to an accident caused by road debris my sway barr brachet broke and I did put a new one on the driver side and the noise disappear on that side . I am looking today at the right side and because is so cheep I am going to change. I will keep you posted.

[Bruno_300TE]

I checked the sway bar bracket and they look perfect. However I found that the springs were slightly mispostitioned: There needs to be a gap between the lower end of the springs and the end of the groove on the control arm where the last winding resides (sorry for the language). Otherwise the spring can move and make noise.
Regards, Bruno

BTW My idea about the eccentric bolts mentioned two posts earlier turned out to be rubbish.

[Kyle Blackmore]

I've had a similar sound in the front of the 300CE. It's more of a 'tunk' when first moving forward or backward. I've replaced the ball joints ,checked and rechecked the wheel bearings checked the caliper mount and replaced the brake pads. The noise has never gone away . It almost sounds like the brake pads shifting in the calipers (they aren't)as it only happens when the car first moves.

[Saint]

Hey Bruno...thanks for the update. I just got my 1990 300TE back from the frame staightener....I have replaced all that good steering and several suspension components. I still have some work to do...but its getting there.

You said there needs to be a gap between the spring and the end of the spring socket on the lower control arm. This does not make sense to me...and I would think that the spring will work its way right back to the "stop". Did you read somewhere that there needs to be a gap?

I am just glad you found it...because this kind of update is truly what makes this forum great.

I now have another piece of info in my knowledge bank should this problem happen to me

[haasman]

I bet it is your your brake pads shifting in the calipers. I didn't have these noise until I installed PBR delux front pads. It seems they are slightly narrower than the OEM/stock pads.

Check it by backing up and stopping, then the going forward and stepping on the brake. You should get the "clunk" "tunk" etc.

I've removed the pads and they don't seem to be damaged by this slight shift.

I really like the PBR Delux pads so I just put up with it.

Haasman

[Bruno_300TE]

Originally Posted by Saint

This does not make sense to me...and I would think that the spring will work its way right back to the "stop". Did you read somewhere that there needs to be a gap?

So far it worked and the spring actually seats better than before. I have attached a picture from the WIS http://mb.braingears.com/124_DISC2/Program/Chassis/
, job 32-0200.pdf. The end of the spring is marked by an arrow. The "gap" I am talking of would be indicated by the green bar. Before, I positioned the end of the spring where the arrowhead is. I am not sure anyone besides me would do the same mistake.
Regards, Bruno

[fivespeed]

Originally Posted by Bruno_300TE

Hi everybody
Car is a 1992 300TE with 150 kmiles. It got a whole suspension rebuild aboout 15kmiles ago. Since the weather got warmer I have a clunk after a while of driving (warm suspension components) when coning to a Stop, when accelerating from a stop, at slow turns.
I redid:
- strut mounts (new)
- shock absorber (tested with new ones)
- ball joints (new)
- sway bar and bushings (new)
- degrease control arm mounts and put new eccentric bolts, torqued to 150Nm instead of 120 Nm (following advice given in a tech bulletin)
- wheel bearings (new)
- idler arm bushing (new)
Nothing helped... My latest theory is as follows: (1) The problem is the eccentric bolts - they are not tight enough. (2) the special washer of the eccentric bolt will only go as far as the groove allows in the bolt, even when substantial torque is applied.
So, I have to grind the washer slightly so that it will go a little bit further on the bolt in order to make it tighter.
Can anyone of you comment on this idea, or do you have another suggestion, something I overlooked? How about the mounting bracket of the sway bar? They are not cracked - could they be worn somehow?
Many thanks and have a good time!
Bruno

It maybe your brake caliper

[fivespeed]

It can well be your axle or brake caliper. Have it checked out