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Front End Clunk: Where to Begin the Diagnosis?

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Old 07-25-2008 | 04:19 PM
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Originally Posted by KenRudd
Killav-

I like the color of your S4 and the rims!


-Ken Rudd
Thanks!
Old 07-25-2008 | 07:25 PM
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Here us my update and fix.

I got to work with a Hunter DSP 600 alignment machine today at my local Sears store. Sure, never take your car to Sears...........

Well, the techs and the 2 big boss's and I put the car up on the machine and I walked them through how to do it, where to do it, and I was so impressed with the service and equipment there, we opened up a corp account with Sears and get one hell of a discount on alignments now.

These guys were fantastic.

Anyway, my clunking has stopped, the car is aligned properly. I had checked some of the possible solutions last night but the clunk was still there. When the alignment was finished everything is peachy.
Old 07-25-2008 | 10:02 PM
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Originally Posted by Dennis Wilson
Worn bushings on the sway bars and linkage can also cause a clunking sound. The rear links are also prone to break at the welds if a large chughole is encountered. BTDT

Dennis

After similar R&R work on my S4, it acquired a 'clunk' over every low speed expansion strip/curb/lip entering garage/.... : turned out to be a slightly loose nut on the drop link to sway bar stud. Another 1/4 turn - and the car was silent.
Old 07-25-2008 | 10:29 PM
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Very useful thread.
Old 07-28-2008 | 12:06 AM
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Well, after a long Porsche weekend, clunk is gone, but some mystery remains:

Lifted car, did 12/6 test. This was fine.

3/9 wiggle showed some play, so I pulled the wheels. The play comes from the ball joint at the rack end (Inner end) of the tie rods. Roughly 1mm of play, maybe less, but enough to notice, and about the same on both sides. I am a little disappointed, because, as I mentioned earlier, they are almost brand new tie rods, but at least I thought I had found the problem and it is an easy fix.

But, I figure, as long as I am in there, I will check the torque on all the various nuts and bolts I touched during the motor mount/ rack replacement job, and some I didn't, like the eccentric nuts. A few seemed a little loose, so they go tightened, and the eccentric nuts were definitely below 88 ft/lbs, and showed signs of movement ( clean spots in surrounding grime), so they got some torque wrench love too. (Are these used in alignment? That would explain the clean spots).

Since there was no way to replace the tie rods over this weekend, and I wanted to talk to the seller about that, I dropped it down and went for a drive. Surprise surprise: no clunk!

Summary so far:
1. Clunk appears to have been due to a loose nut/bolt. No way to tell exactly which one, but I suspect an eccentric, and;
2. I still have a problem with play in the tie rod ball that does not have any immediate symptoms, but bugs me because it should be perfect. Hopefully seller will make good.

Last edited by KenRudd; 07-28-2008 at 10:41 PM.
Old 07-28-2008 | 12:34 AM
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maybe the outer tie rod ends were replaced and not the inners. Its kind of rare to see new inner tie rods having play, they should go for atleast 75,000miles or more unless they have gotten wet with water or ATF
Old 07-28-2008 | 12:44 PM
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I did the tie rods myself, unwrapped them from factory wrapping and bolted them in. The whole thing was replaced, not just the ends. Only thing I did not do myself on the front end was the alignment.

I agree, no reason at all for inner play. Bugs me greatly. Its not a big job to replace them, but I hate doing things twice.
Old 07-28-2008 | 01:37 PM
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Ken,

Did you torque them to the 200+ lbs? If not they may have just come loose.

Dennis
Old 07-28-2008 | 03:59 PM
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200+ Lbs where? On the eccentrics ? Tie rods into the rack? ( yes, I know I said "concentric" earlier. Spell check abuse!)
Old 07-28-2008 | 04:40 PM
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It is preferred to lock the rack rod in place via the centering screw hole before condemming any "3 to 9"play to tie rod ends .... a M12x1.5 bolt turned down to a 2mm nipple will lock the rack.
Unlocked, the rack rod will have at least 1mm of play, even with the steering column locked.

The alternative is a two man job .... pull the boot back and grasp the universal joint on the rack input shaft while someone does the '3 to 9' wiggle: then one can view the inner joint.
Old 07-28-2008 | 04:50 PM
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I thought I might be crazy and missed something, but I just rechecked the WSM, pgs 40-02 and 40-03 and I don't see anything over 103 ft/lbs on the front of the car ( 108 ft/lbs for tie rod to rack WSM 48-2)...

-ken Rudd

Last edited by KenRudd; 07-28-2008 at 10:39 PM.
Old 07-28-2008 | 04:58 PM
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Garth,

Although I did not lock down via rack centering screw, I did peel back the boot and watched the play directly in action at the ball joint: I could see the ball moving in the socket. Definitly not rack movement.

I used a variation on your plan B: holding the steering column steady with the a large screwdriver up through the universal joint in that shaft while moving the tire 3/6. Totally forgot about the easier, better way!

-Ken Rudd
Old 07-28-2008 | 07:50 PM
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Originally Posted by KenRudd
200+ Lbs where? On the eccentrics ? Tie rods into the rack? ( yes, I know I said "concentric" earlier. Spell check abuse!)
C'mon Ken, get with the program!
How do you expect us to help you in any meaningful way when you're using incorrect terms?

Old 07-28-2008 | 10:44 PM
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Adam,

Aw shucks.........Thats nothing compared to some of the "incorrect terms" I've used after shearing /stripping a Cam Cover bolt or banging my knuckle into the sharp edge of a radiator fan.

But in the interest of future searches, I went back and edited the errors.

-Ken Rudd
Old 07-31-2008 | 06:45 PM
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Update and Happy Ending:

As a background, I bought/installed the rack and tie rods before joining Rennlist.

I bought those items as a package from Griffiths (http://www.griffiths.com).

I contacted them with my concerns on the play at the ball link and their response was essentially perfect: Paraphrasing: "We will send you a replacement set or a refund, your choice". No hassles, no request to inspect the parts first, no questions asked. Griff even checked the in stock units he had to see if they showed the same symptoms (they did not).

I have seen previous posts critical of their customer service. In this case I can say without reservation that Griff's service was OUTSTANDING. It could not have been any better.

-Ken Rudd




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