This car could certainly use new lower control arms to freshen the bushings and that is on the "list." But lately I've been fighting with the anti-roll bar end link connection to the bar on the driver's side. It seemed to be slipping in the bar since the hole was oblong due to the nut being loose for a long period of time. But lately the clunk has been getting worse and it feels different than the end link issue. And it happens in situations where I would not expect if it was the end link. I needed to rule out something more serious like a ball joint.
Got under the car, looked at stuff, tightened one of the lower control arm mount nuts a little. Lower ball joint boot looked fine. Supported the LCA with a 4x4. Used pry bar on tire. Did not see movement in lower ball joint. But SOMETHING is clunking under here!! I reached up and just sort of pushed on the upper control arm. I felt movement. Uh oh.
Got out from under the car. I can actually move the upper control arm up and down due to the ball joint play. It is significant. Now the upper doesn't take very much load but obviously it needs to not fail. The boot does not seal fully. So...this BJ is toast. This must be what I am feeling.
There is some good news. It looks really easy to change the upper control arm.
05 STS front end clunk
05 STS front end clunk
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Re: 05 STS front end clunk
Mevotech sells a complete arm with bushings and ball joint.
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=399
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=400
Right is $81 and left is $84. Wondering if I should just do both. The other boot was better but not perfect.
The FSM seems to suggest that the UCA is part of the upper shock/spring assembly that bolts up through the engine bay.
Yeah, see, AC Delco 19181780 and 19181781. $168 per side. Seems unnecessary to replace all that. A lot more work, too, assuming I can do the UCA in-car. Look at all that fancy aluminum though. Guess I should order both UCAs and do both. I'm sure a set of lowers would do wonders for the car but not ready to do that one just yet.
The front uppers are compatible with:
CADILLAC
CTS
2008-2014
CADILLAC
SRX
2004-2009
CADILLAC
STS
2005-2010
I still find it interesting that the 2nd gen CTS (Sigma 2?) used pieces and parts from the original stretch Sigma on the SRX/STS.
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=399
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=400
Right is $81 and left is $84. Wondering if I should just do both. The other boot was better but not perfect.
The FSM seems to suggest that the UCA is part of the upper shock/spring assembly that bolts up through the engine bay.
Yeah, see, AC Delco 19181780 and 19181781. $168 per side. Seems unnecessary to replace all that. A lot more work, too, assuming I can do the UCA in-car. Look at all that fancy aluminum though. Guess I should order both UCAs and do both. I'm sure a set of lowers would do wonders for the car but not ready to do that one just yet.
The front uppers are compatible with:
CADILLAC
CTS
2008-2014
CADILLAC
SRX
2004-2009
CADILLAC
STS
2005-2010
I still find it interesting that the 2nd gen CTS (Sigma 2?) used pieces and parts from the original stretch Sigma on the SRX/STS.
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Re: 05 STS front end clunk
Oh I can actually buy just upper ball joints.
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=459
$24 for Mevotech or $47 for AC Delco. Hmm. I bet the bushings are fine since the UCA has a pretty easy life. Might be more work to deal with pressing it out and in though. I'd be less likely to need an alignment with just the ball joint replacement. There is a good chance the aftermarket UCA is very slightly dimensionally different, enough to throw off the alignment I just got....sigh.
https://www.rockauto.com/en/moreinfo.ph ... 42&jsn=459
$24 for Mevotech or $47 for AC Delco. Hmm. I bet the bushings are fine since the UCA has a pretty easy life. Might be more work to deal with pressing it out and in though. I'd be less likely to need an alignment with just the ball joint replacement. There is a good chance the aftermarket UCA is very slightly dimensionally different, enough to throw off the alignment I just got....sigh.
Re: 05 STS front end clunk
$165.34 shipped for both front upper control arms.
Wondering if I should park the car now that I know it's quite loose...
142k, FWIW.
Wondering if I should park the car now that I know it's quite loose...
142k, FWIW.
Re: 05 STS front end clunk
Yeah in fact here are the FSM instructions for doing the upper. They tell you to R&R the entire upper shock assembly and the shock/spring itself. I am ot doing that unless replacement of the UCA in-car is not possible (and then I'd do it on the bench). Evidently GM considers that whole assembly (minus the shock/spring) as the LRU (lowest replaceable unit).kevm14 wrote:The FSM seems to suggest that the UCA is part of the upper shock/spring assembly that bolts up through the engine bay.
Yeah, see, AC Delco 19181780 and 19181781. $168 per side. Seems unnecessary to replace all that. A lot more work, too, assuming I can do the UCA in-car. Look at all that fancy aluminum though.
Eh, "line-replaceable unit"
https://en.wikipedia.org/wiki/Line-replaceable_unit
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Re: 05 STS front end clunk
I probably would considering you have other options.Wondering if I should park the car now that I know it's quite loose...
Re: 05 STS front end clunk
Control arms are due today. I do not think I will get a chance to tackle this before Sunday realistically. Also not sure if I will do both at the same time. Depends on the difficulty/time I guess. If I do one and think my alignment is off, that would probably force me to do the other one and get an alignment. If the alignment seems OK still, I might wait a little longer on the pass side. We'll see. It's probably a matter of time since the boot is compromised.
Re: 05 STS front end clunk
Need this for torque specs in the garage.
Driver's side is almost done. Had to pull everything and replace the arm off the car. Still not that bad to do.
Driver's side is almost done. Had to pull everything and replace the arm off the car. Still not that bad to do.
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Re: 05 STS front end clunk
Done. Really wasn't that bad even though I did have to completely remove the shock and spring.
Here is the driver's side new arm. This is Mevotech, made in China. Not sure what the OEM was for the originals but I will see if there is a stamping. Loosened the 18mm nut. Then the ball joint started spinning so I held it back with a 5mm allen wrench. Came right apart. This is not a deep taper style. It is more like a dish or cone. Again, the upper ball joint on a design like this does not see much load. The bushings were preloaded for ride height so it wanted to spring up but it wasn't going to go anywhere. Next I loosened the lower shock yoke nut. I think it was 24mm. 133 lb-ft on that one. It takes the entire load of the shock and spring so no wonder it is substantial. It took a lot of continuous impacting but came off eventually. After that, I began removing the 5 upper shock mount bolts. There is one on the side of the tower near the master cylinder. Don't forget to disconnect the MR shock plug. Also disconnect the ride height sensor from the control arm. It took some prying to get the shock off the yoke bolt but I got it. After that it was just a matter of playing games to get the lower shock piece untangled from the wheel speed sensor harness, without denting my fender/wheel well. Some jostling around and turning the knuckle over to the side later, and I got it out. I took these pics to make note of where the arm was installed and torqued. New control arm installed. It would have been more work I think to remove the shock and spring from the shock mount, so I don't regret getting the cheaper control arms vice the whole assembly. And here is the passenger side installed... And the shock plugged back in. That side bolt was annoying. Very close to the battery. I was able to do it slowly with an open end/box end wrench. Kind of tedious. I couldn't torque this one so I made it tight. 83 lb-ft is the spec anyway.
Here is the driver's side new arm. This is Mevotech, made in China. Not sure what the OEM was for the originals but I will see if there is a stamping. Loosened the 18mm nut. Then the ball joint started spinning so I held it back with a 5mm allen wrench. Came right apart. This is not a deep taper style. It is more like a dish or cone. Again, the upper ball joint on a design like this does not see much load. The bushings were preloaded for ride height so it wanted to spring up but it wasn't going to go anywhere. Next I loosened the lower shock yoke nut. I think it was 24mm. 133 lb-ft on that one. It takes the entire load of the shock and spring so no wonder it is substantial. It took a lot of continuous impacting but came off eventually. After that, I began removing the 5 upper shock mount bolts. There is one on the side of the tower near the master cylinder. Don't forget to disconnect the MR shock plug. Also disconnect the ride height sensor from the control arm. It took some prying to get the shock off the yoke bolt but I got it. After that it was just a matter of playing games to get the lower shock piece untangled from the wheel speed sensor harness, without denting my fender/wheel well. Some jostling around and turning the knuckle over to the side later, and I got it out. I took these pics to make note of where the arm was installed and torqued. New control arm installed. It would have been more work I think to remove the shock and spring from the shock mount, so I don't regret getting the cheaper control arms vice the whole assembly. And here is the passenger side installed... And the shock plugged back in. That side bolt was annoying. Very close to the battery. I was able to do it slowly with an open end/box end wrench. Kind of tedious. I couldn't torque this one so I made it tight. 83 lb-ft is the spec anyway.
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Re: 05 STS front end clunk
I did a short road test since my radiator hose still leaks. Side note, this transmission really shifts well, after the latest fluid change and the LubeGard additive.
It clunked pulling out of the garage. Then it clunked a few times on the test drive. Then it seemed to stop and I couldn't get it to do it again on the rest of the drive. Did something settle? Is something else loose?
I can tell you this: the upper ball joint was DEFINITELY failed. In fact, here is a short video. Caused by boot failure basically.
https://www.youtube.com/watch?v=akB6he_ ... e=youtu.be
The passenger joint did not feel failed yet but I did both anyway.
I am withholding judgement until I really get it back on the road. It could be that the end link still needs to be fooled around with as I had previously been planning, tentatively. Or lower control arm stuff?
Not quite sure if I need to rush out and get an alignment as I don't think it is changed. Definitely need to commute in it after I fix the hose and see what the clunking situation is. There were places it pretty much would always do it.
It clunked pulling out of the garage. Then it clunked a few times on the test drive. Then it seemed to stop and I couldn't get it to do it again on the rest of the drive. Did something settle? Is something else loose?
I can tell you this: the upper ball joint was DEFINITELY failed. In fact, here is a short video. Caused by boot failure basically.
https://www.youtube.com/watch?v=akB6he_ ... e=youtu.be
The passenger joint did not feel failed yet but I did both anyway.
I am withholding judgement until I really get it back on the road. It could be that the end link still needs to be fooled around with as I had previously been planning, tentatively. Or lower control arm stuff?
Not quite sure if I need to rush out and get an alignment as I don't think it is changed. Definitely need to commute in it after I fix the hose and see what the clunking situation is. There were places it pretty much would always do it.