: Rear Coil Spring - Broken or Improperly Installed?

03-20-13, 05:00 PM
I noticed last weekend when replacing the rear end links (cool and easy job btw) that one of my rear coil springs looked like the leaning tower of Pisa. It didn't look right. When compared with the driver side...it confirmed that something is really wrong. I had my shocks replaced last July and so that is the last time they were touched. I brought it back to the shop that serviced the shocks I didn't hear any impacts or nothing (very small shop). I was brought back in and suddenly they looked to be seated properly...I was puzzled (turned by hand????). So the rear acted up again since that visit on Saturday. I took pictures Saturday and then again today. The situation today is the same as it was when I changed the links. Feels like the rear is not following the front...makes the steering feel imprecise and sloppy. I attached some pics of the alleged culprit. I have never had a coil spring go bad on me so I have no idea what it is going on. Is it broken or not well installed? Thanks!

03-21-13, 09:38 PM
I forgot to post the pictures of the other spring on the driver's side that is sitting squarely. Here they are. Any ideas what is going on between both sides?

Thanks. 105514105515

03-22-13, 02:21 AM
It look that is off center or bent. If your are able take a look at it when the car is flat ground or put a jack under the control arm and lift the car that way and then removel the wheel and see how the spring look conpress.

03-22-13, 06:41 AM
It looks just fine to me.

They're clocked differently, so each coil is going to look a bit different at the ends, where the coil tapers in towards the center.

If the rear ride height is the same on both sides, they're perfectly fine.

03-22-13, 12:06 PM
It does really look off center and that is what drew my attention initially. I can't really get a good measure of ride height here in Kentucky because it is very hard to get on true flat ground (very very hilly). I've tried several times and never get the same measurements due to that. I spoke to a friend this morning and he told me that springs are tighter at one end and looser at the other. The loose end he said was supposed to be at the bottom to absorb road irregularities and then the top is tighter to have the least of the irregularities transfer to the chassis. Are our springs made that way? I'm thinking that either he is right or the spring is weak? Then again I am a rookie when it comes to DIY mechanics. Any ideas? Thanks.

Tom's Caddy
03-22-13, 01:00 PM
Gas stations are made on flat ground take you're measuring tape and go fill up.:o

03-22-13, 01:03 PM
It only looks off center because you're viewing it from an angle that the taper in the spring (toward center) is very visible.

Also, both springs are "wound" in the same direction, and viewed from the front, spirals down to the left (the left side of each coil is lower than the right side). When the car is jacked up, and the lower control arms pivot down, they pull the bottom of the springs forward. Since the springs are both wound in the same direction, that makes them look different on both sides. On the drivers side, it makes each coil look flat and level. On the passengers side, it makes each coil look more slanted than they already are, giving the illusion that the spring is leaning more than the other side.

03-22-13, 06:23 PM
Thank you for the help. @MoistCabbage: it is off center when the car is sitting on the ground also. Difficult to tell on the pictures due to the darkness. I adjusted the lighting so you can see. This is taken through a gap in the rim. 105552

The other one is perfectly square with the perch when on the ground. @Tom's Caddy: I feel like an idiot for not having thought that one up! lol I just measured it and there is a slight touch over a 1/4 inch difference between the affected side (higher and not centered) than the driver side (lower and centered). I am assuming that is why I am having poor handling, steering returnability issues and why the car is pulling left (despite many alignments). The steering returns to center when turning right but not when turning left. As I mentioned in the initial post the mechanic repositioned it Saturday but it didn't take long for it to be back in the same position. I am assuming that the coil is not broken/weak if that side of the car is higher. What can be the problem?

03-22-13, 09:18 PM
Again, it's not off center. The coil tapers in at the top of the spring. At the angle you're looking at it (and taking the pictures), the taper is what's making it look off center. Look at the picture, look how far the coil on the left sticks out past the rubber isolator. Then look to the right, just above the rotor. That part of the coil sticks past the isolator the same amount.

Did you "settle" the suspension before taking the measurements? Push the rear bumper down ~1", lift it up ~1", and slowly release it, then repeat for the front? Did you check for equal tire pressure all around? Take everything out of the car? Even is one side is 1/4" low, it's not enough to cause the problems you're describing. And if the side you think there's something's wrong with is the higher one, it's definitely not a spring problem. Springs can only sag or break, and either will cause a LOWER ride height.

03-22-13, 09:56 PM
I didn't do the settling thin before measuring. But my tire pressure is equal all around (I'm OCD with that) and there is never anything of considerable weight in my car. The only thing is a little cover for the backseat for my dog. Otherwise my trunk is empty and the cabin is relatively empty. Ill try that test in daylight tomorrow and report back. Thanks again.

Tom's Caddy
03-23-13, 10:01 AM
CaddyMak I would go to my local Caddy dealer and just very nicely ask do you have a tech that is really good with caddy springs and shocks (suspensions), could he just humor me for a minute and have a quick look at something for me to tell me if this is normal or not. If they are not busy, I would just walk him outside towards you're car the whole time telling him what you think and asking if that could be the cause of you're steering issue. I would even take you're pictures as a last resort and ask if that is normal just over the counter if they won't look at it without an appointment (charge), also if you are taking some of those pictures through the wheels on the car try to find another DTS on the lot and have a peek. You just might get the answer you want NO CHARGE.:)

03-23-13, 12:50 PM
@Tom's Caddy: I think I will be doing that Monday morn. Thanks for the tip.
I just did the test and the passenger side is still higher than the driver side. I took a quick look at the GM parts and AC Delco sites and it looks like the right side shock part has been replaced with a new number. I don't know if this has any relation to the height issue. I bought this shock and it had it installed in July. At that point the # was 504-116 and now it is 504-147 (it was made by BWI; the Chinese co. that bought out Delphi). On the Gm parts list the number has been replaced too from 15873314 to 19300026. I do not know why numbers are changed but I'm assuming it is to upgrade something. The other thing is there is a (new?) part number for the springs that do not match the number on the tag (seen in picture). But I'm assuming that is not a problem because I would've read about complaints here on the forum (as it was the case with the front brake pad/rotor combo).

Measurements after the settling the suspension:
Passenger: a little over 29 3/8 inches (service allowed 28.3-29.1 in; Service Preferred 28.7)
Driver: 29 1/8 inches (service allowed 28.3-29.1 in; Service Preferred 28.7)
I bought that manual off of Ebay that one member suggested in a thread a month or so ago. It looks like my driver side is just at the limit of the trim height specifications while the passenger side is over it. The recommended solution in the manual is to change the springs but I don't know if that is appropriate. The only other thing I can think of is maybe the pigtails (sitting on the control arm) are pointing in the wrong direction? Are they both supposed to be pointing towards the driver side (left side of vehicle)? On a last note, my brother who works in tires for years now explained that ride height in the rear affects caster in the front, especially when it is beyond specifications. He says that may possibly explain the steering issue. But I am no alignment, geometry specialist.