03 Seville SLS Rear Shocks

It's pronounced "chassy." Brakes, suspension...things that make the car fun or a death trap
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Adam
Posts: 2240
Joined: Wed Oct 23, 2013 9:50 pm

03 Seville SLS Rear Shocks

Post by Adam »

Customer states there's a banging in the rear.

This car is up to >180K on almost entirely OEM suspension. There were several variation on fancy suspensions in these Sevilles, fortunately the real expensive ones were only optional on the STS (ManaRide), which this one isn't. So it's conventional McPherson strut front and aid-assist shocks in the rear. It does have an auto leveling system which GM had been putting in many of their full size cars for a number of years (including the Fleetwood). This is a similar system to the older D-bodies with level sensors and a pump assembly. Conveniently, like the other G/K cars, the pump is located under the rear seat so other than an exhaust port it is never exposed to the elements which probably has contributed to the longevity.

We opted to get OEM 'Delco' replacements for this, mostly due to the non-standard design of the shock/bladder assembly and the internet providing mixed information on how compatible some of the aftermarket stuff was. The RH one is readily available, but the LH one is EOL. I did manage to find one at Summit, but it was a ~12% cost increase. In hindsight, the thing that makes these positional is only the relative alignment of the offset upper mount to the shock (180 out from L to R). The shock bodies are otherwise identical. Oh well.

The OEM stuff is branded Delphi, which isn't surprising, but the AC Delco replacement stuff is branded BWI, presumably after the airport? Probably not. I'm pretty sure the rear air bladders have never held air, mostly evidenced by the drastic increase in 'bound' ride performance of the new shocks. Also, the compressor now only runs for seconds after starting the car rather than several minutes (presumably on a timer). I am slightly surprised that there isn't a BCM code for this, but I haven't been paying too much attention.

Pics is attached. "Place inline" is missing? is that expected?

Regardless, the banging in rear. I think this was actually the upper mount, being exasperated by incorrect bound 'spring rate' due to the failed bladder. I was able to get vertical motion of the shock stud in the upper mount indicating it was either assembled on a Friday and not fully tightened, or the rubber degraded sufficiently to allow for motion of the mount before the rubber starting compressing.

Installation was so easy, I didn't take any pics. Something like:
1. Jack up your car
2. Remove wheel
3. Disconnect air line
4. Remove side trunk liner
5. Unbolt 2-bolt upper mount from inside trunk
6. Unbolt 2-bolt lower mount from lower control arm (like a B/D body or every GM ever shock)
7. Remove shock
8. Installation is reverse of removal
9. Repeat for other side.

The FSM says to not to fully put weight on the shock at first and cycle the air pump on to fill the bladder before ultimately lowering the car.

Great success. Now the only noise out back is the stuff in the trunk crashing around.
Adam
Posts: 2240
Joined: Wed Oct 23, 2013 9:50 pm

Re: 03 Seville SLS Rear Shocks

Post by Adam »

Turns out the photo didn't attach. The photo upload complains it can't determine the dimensions of the image? How do you work this thing?
Adam
Posts: 2240
Joined: Wed Oct 23, 2013 9:50 pm

Re: 03 Seville SLS Rear Shocks

Post by Adam »

Doesn't work in Edge either. Where do I submit my support ticket?
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: 03 Seville SLS Rear Shocks

Post by kevm14 »

BWI is the Chinese company that now owns the Delphi stuff. They made the new MR shocks I put into my STS. I'm somewhat surprised to see that extend to non-MR but maybe it's all Delphi shocks or something.

Images work fine for me....
20210518_130054.jpg
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: 03 Seville SLS Rear Shocks

Post by kevm14 »

Trying the image Adam e-mailed to me.
Seville rear shocks.jpg
Adam
Posts: 2240
Joined: Wed Oct 23, 2013 9:50 pm

Re: 03 Seville SLS Rear Shocks

Post by Adam »

I downloaded the file I emailed you and I can post that fine, bot not the original. Perhaps it's the rotation as what I grabbed from the email was converted to landscape. Next time I'll take landscape pictures and see if that works.
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