05 STS front end clunk

It's pronounced "chassy." Brakes, suspension...things that make the car fun or a death trap
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS front end clunk

Post by kevm14 »

I road tested after my coolant hose and throttle body. Which gave me a short time to examine the clunk situation.

It is possible I still felt something on the floor but also possibly my imagination. Even still, it seems almost completely gone. Again, commuting will be a better test but I am optimistic at this point.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS front end clunk

Post by kevm14 »

Drove an hour. It actually feels a little better to me but then again I've been driving the Roadmaster all week. But it does feel better over bumps I think.
kevm14
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Re: 05 STS front end clunk

Post by kevm14 »

On the commute in yesterday it felt quite good.

On the commute home I drove over the most clunk-prone areas (for whatever reason). I did hear and possibly feel something. However, it was different and also quieter. I guess it could still be the end link to bar connection on the driver's side. That nut is so tight I just can't believe it is slipping but who knows. I believe this is the same mild clunk that I felt and reported from my initial test drive after repair, so I can't be totally surprised here.

This doesn't really take away from my repair, because I did fix a pretty major issue. And it does feel a WHOLE lot better, after driving more.

I will keep driving and see what I think. I can still try disconnecting the end link at the lower control arm and tie the end link up somehow (ziptie to the bar I would guess) and just confirm no noise (and super weird handling). Not going to attack that at the moment. Plus, that is not a safety issue at all. The clunk before was getting bad and obviously I was right to dig in since ball joints are critical. Or....maybe the passenger side end link itself is just getting some play? Don't want to engage the parts cannon without a proper diagnosis even if it takes a year and 10k miles to pinpoint. But disconnecting the driver's side would also help me examine the passenger side since the bar would not be restricted and I could check for play pretty easily.

On the other hand, if the noise was still present after disconnecting the driver's side end link, that would be a useful data point and I might entertain a lower control arm replacement at that point. Since it would also rule out the passenger side end link.

So really this thread is not over I guess. Hey the car has 142k New England miles on it. That is the way it goes.

That means the next step is my driver's side end link experiment. I would say it will all depend on how annoyed I am with the remaining issue.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: General STS thread

Post by kevm14 »

Definitely getting some crunchy clunks in the STS. I think it is different from last time as it still seems tight most of the time over most bumps. I am getting closer to just doing lower control arms. It needs bushings anyway.

Mevotech has them for $155 and $175. Wonder if I should look for OE.

Oddly, it is also a greaseable ball joint. But I kind of like their sales pitch.
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=409
Supreme is Mevotech's benchmark technology, providing enhancements and quality that are simply beyond OE. Supreme parts are engineered to keep you on the road longer and designed to improve part life, performance, and durability.
- Greaseable design minimizes friction and reduces heat, providing less wear on the bearing and extending service life
- Knurled housing provides a more secure fit, for increased contact area and maximum safety
- Metal-to-metal sintered bearing with added grease channels withstands tough loads and extreme heat to prevent part failure and extend life
- One way grease relief valve eliminates excess grease while keeping contamination out, protects seal from pressure damage caused by excessive grease build up
- Includes circlip to increase safety and entend service life.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: General STS thread

Post by kevm14 »

Did a little more research and found the GM number for the LCAs. Plugged that back into Rockauto and they did in fact offer it, but their listing shows 06 and up, which seems incorrect (since a GM parts website pulled up the part for my 05, per VIN even). Anyway, Rockauto sells the AC Delco for $190. So OEM for $190 or the Mevotech for a little less. At that point it's kind of a matter of whether I think the Mevotech is actually the better part (i.e. longer lasting bushings or whatever they think). Price doesn't really seem too big of a difference here.

https://www.rockauto.com/en/moreinfo.ph ... 44&jsn=508
https://www.rockauto.com/en/moreinfo.ph ... 44&jsn=510

Driver: 25862781
Passenger: 25862782

And yes, AWD is different than RWD.

So new LCAs get me:
- New bushings at frame
- New ball joint (Mevotech is greasable, the AC Delco should not be if it is really OEM)
- New shock yoke bushing and bolt

And unlike with the uppers, there is no way to get away without an alignment since the lower mount holes are slotted for caster/camber. I can scribe the frame all day but it won't be exact. It will throw off caster, camber AND toe, guaranteed. In which case I am glad I delayed the alignment after the uppers.

Next step is to investigate FSM R&R instructions and see what it might take. Hoping I don't have to pull the axle out of the hub/bearing/knuckle. Other than that, I think it will be pretty straight forward.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS front end clunk

Post by kevm14 »

The only interfering item appears to be the steering rack. So if I really find that it is an interference item (and maybe it is to actually remove the rear LCA bolt), it says to remove the rack bolts (there are two), and raise it to gain clearance. The hardest part about that may just be getting to those bolts, since they face up and I'll be on the ground.

Other than that, there's nothing in the way of this job. I suspect this only applies to the AWD because of the rack location. In fact I will check the RWD instructions.

Eh, actually it recommends the same.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: General STS thread

Post by kevm14 »

kevm14 wrote:And yes, AWD is different than RWD.
Ohhh! Check this out.

RWD LCA. Looks like a normal LCA, except for the shock yoke design (stud and bushing).
RWD front LCA.PNG
AWD LCA. Notice anything? The ball joint is flipped upside down! Why? To clear the axle. Well that makes all the sense in the world. Amazing.
AWD front LCA.PNG
Of course, that begs the question: what does this mean for the greaseable Mevotech ball joints?

The answer is, they give you a 90 degree grease fitting, as long as it tightens down facing the right direction of course...

Greaseable is kind of annoying. I would end up doing it every oil change and I guess just doing two ball joints isn't really that difficult. But, Bill pointed out that the high moly extreme duty grease I got from TSC for the heavy equipment I was maintaining during the driveway job is not really low temp rated (even as I have been putting it into my B-bodies and the truck). I really should find the right stuff for the STS. Or buy the AC Delco LCAs for $50 more for the set.
Attachments
05 STS Lower Control Arm Replacement (RWD).pdf
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05 STS Lower Control Arm Replacement (AWD).pdf
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Adam
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Joined: Wed Oct 23, 2013 9:50 pm

Re: General STS thread

Post by Adam »

kevm14 wrote:The ball joint is flipped upside down! Why? To clear the axle. Well that makes all the sense in the world. Amazing.
It also means you will definitely have to remove the axle to replace the LCA.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 05 STS front end clunk

Post by kevm14 »

Nope. The knuckle has a large hoop and I believe there is room enough to lift the ball joint stud out and pull the knuckle away a little. I don't think I need to touch the axle. Now, about raising the steering rack...

See the lower hoop? The hub area is a completely separate "compartment" if you will. And, removing the axle wouldn't help anything since the knuckle itself must, by design, have enough room for the ball joint stud to slip in and down.
15775070-2008-2014-cadillac-cts-cts-v-steering-knuckle-awd-new-oem-right-front-15775070-7.jpg
More pics.
2013-08-02_200831_pic.gif
2013-08-02_201039_pic.gif
2013-08-02_201039_pic.gif (23 KiB) Viewed 1819 times
Adam
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Joined: Wed Oct 23, 2013 9:50 pm

Re: 05 STS front end clunk

Post by Adam »

What is this thing, some sort of European car?
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