[sjwoodruff]

Thanks for the input everyone gave on my previous strut replacement post.

Another question that maybe someone can help me with. I've been scouring the net looking at passive strut systems. I found something interesting - apparently AC/Delco has a passive front and rear system available for the '98 STS.

GM part number is 88946635 for the rear PAIR of shocks. At GM Parts Direct the price with S/H comes out to be $87.36.

GM part number is 88985526 for each front strut. At GM Parts Direct the price with S/H for a pair is $130.71.

For the math challenged, that would be $218.07 total for a complete set of four. Has anyone out there ever purchased and installed these? I'm not too concerned with codes based on Krashed's advice with the damper plates, but I'd like to see if anyone else has taken the plunge and get some feedback first on ride quality and installation compatibility. This seems like a great deal if they are indeed compatible. Less money than Boston Suspension, Arnott Industries and Strutmasters. Plus it's OEM, so that would seem to make more sense, no?

 

[JimD]

Hang in here with me as I am (easily) confused.

Looking at your post and drilling down through Rockauto and ACDelco web sites, I find two part #s for a passive ACDelco front strut; 580-120 for left and 580-121 for right. We know the left and right struts are different (mirror images of each other).

So the single GM part #88985526 for passive front struts has me scratching the dog's head. Have you looked at and touched part #88985526?

Any additional information would be appreciated; my '98 has 143,xxx miles on the factory installed struts and you can imagine how much rebound I am living with.

 

[sjwoodruff]

Jim,

I have a reliable parts source at a local dealership. I plan on speaking with him tomorrow. I'll keep you posted.

Check Delco's website again - look up parts for your car by inputing your vin. Go to strut assemblies. You'll see Delco part number 503-379, and it clearly states that you need (2). The ACTIVE struts are 580-120 and 580-121, and cost substantially more. These must be the same units that the car rolled off the line with new, if I'm not mistaken. Through Rock Auto, with shipping, my price was close to $1,250 for actives, and on Gm Parts Direct with shipping, it was still about $950 for the active pair. Ouch...no wait, OUCH!!! :holycrap:

Note - Delco part numbers and GM part numbers are not the same. GM part # for the PASSIVE front strut is 88985526. Through Rock Auto, the shipped price would be $146.48 for a pair, and GM Parts Direct is $130.71 for a pair. It appears the Delco passive rear shocks are sold as a pair. GM Parts direct price shipped is $87.36 (to central Ohio).

I've not laid my hands on these yet. I'll check with the experts to see if this is a mirage, and find out what other components, if any, are necessary for a trouble-free, code-free install. I'll post again tomorrow or Friday with my findings.

 

[JimD]

Good deal, I'll be watching and oiling up the impact wrench.

 

[91TexasSeville]

Jim,

I have a reliable parts source at a local dealership. I plan on speaking with him tomorrow. I'll keep you posted.

Check Delco's website again - look up parts for your car by inputing your vin. Go to strut assemblies. You'll see Delco part number 503-379, and it clearly states that you need (2). The ACTIVE struts are 580-120 and 580-121, and cost substantially more. These must be the same units that the car rolled off the line with new, if I'm not mistaken. Through Rock Auto, with shipping, my price was close to $1,250 for actives, and on Gm Parts Direct with shipping, it was still about $950 for the active pair. Ouch...no wait, OUCH!!! :holycrap:

Note - Delco part numbers and GM part numbers are not the same. GM part # for the PASSIVE front strut is 88985526. Through Rock Auto, the shipped price would be $146.48 for a pair, and GM Parts Direct is $130.71 for a pair. It appears the Delco passive rear shocks are sold as a pair. GM Parts direct price shipped is $87.36 (to central Ohio).

I've not laid my hands on these yet. I'll check with the experts to see if this is a mirage, and find out what other components, if any, are necessary for a trouble-free, code-free install. I'll post again tomorrow or Friday with my findings.

This is a fairly easy DIY project. Before you start, be sure you have the correct socket size (13mm if I recall) to remove the front hub assembly. It is all pretty much straight forward as they come with instructions. It is helpful to mark the washers on the top front shock mount before you remove the old ones as this helps to keep the alignment well enough for you to drive to a front end shop for a proper alignment when you are done. Yes, you will need to do that!

GM passives (I believe) have a "fake" sensor built into the front shocks to stop the Service CCR message.

I used Monroe passives which require a little "doctoring" for the front, but rears are a snap. I used 4 hours to do the whole job from lifting the car to setting back on the ground. Yes, I screwed around a lot!

 

[Tombo47]

the real question is, how do these passive struts perform? Is the ride similar? or are you goona be drivign a wooden wheels stage coach? Whats the difference? Get abck at me, ive been curious for a while

 

[sjwoodruff]

Though I've never changed out struts on a '98 STS, some of the other threads that I've read indicate that the struts are mounted in such a way that they don't affect alignment. Oh well, if they do, I'll get one, I suppose.

 

[91TexasSeville]

the real question is, how do these passive struts perform? Is the ride similar? or are you goona be drivign a wooden wheels stage coach? Whats the difference? Get abck at me, ive been curious for a while

I wish I could give you a definitive answer. The passives in my opinion are just fine. No buckboard road feel, and no body lean, which is most critical to me. I like them and have them on all my Cadillac's. The 92 has OEM shocks installed by the previous owner, and I can not tell the difference between that car and the newer Cadillac's I own with passives. That is not a definitive answer, just my opinion.

 

[91TexasSeville]

Though I've never changed out struts on a '98 STS, some of the other threads that I've read indicate that the struts are mounted in such a way that they don't affect alignment. Oh well, if they do, I'll get one, I suppose.

The instructions CLEARLY state an alignment is imperative. I don't concern myself with chances others take. My tires cost way more to replace than an alignment, and that is only one chance you take.

 

[sjwoodruff]

the real question is, how do these passive struts perform? Is the ride similar? or are you goona be drivign a wooden wheels stage coach? Whats the difference? Get abck at me, ive been curious for a while

My STS is the 2nd car I've owned with an active suspension (other was a Stealth Twin Turbo). Every other car I've ever owned has had a passive suspension system. I highly doubt the passive system will ride as soft over bumps, or tighten up as firmly through the corners as the active system does. I would, however, expect the passive system to give a decent ride under average driving conditions - especially considering the fact that these aren't aftermarket parts. My front struts are shot, rear shocks are still good. I've got so much rebound right now, that anything would be an improvement. I just need to make sure they're compatible. If so, I think this is valuable info because I just don't trust aftermarket stuff. Plus, the aftermarket kits are all substantially more $$.

I'll update everyone once I can talk to the parts guy at the dealer I know.

 

[91TexasSeville]

My STS is the 2nd car I've owned with an active suspension (other was a Stealth Twin Turbo). Every other car I've ever owned has had a passive suspension system. I highly doubt the passive system will ride as soft over bumps, or tighten up as firmly through the corners as the active system does. I would, however, expect the passive system to give a decent ride under average driving conditions - especially considering the fact that these aren't aftermarket parts. My front struts are shot, rear shocks are still good. I've got so much rebound right now, that anything would be an improvement. I just need to make sure they're compatible. If so, I think this is valuable info because I just don't trust aftermarket stuff. Plus, the aftermarket kits are all substantially more $$.

I'll update everyone once I can talk to the parts guy at the dealer I know.

There is logic in your opinion, and yes passives can NOT replace OEM actives cycle for cycle, that is a physical impossibility. In my opinion they perform just fine, and are hands down way, way, better than worn or shot active struts.
I think you will be very surprised and pleased. Yes, let us know your thoughts when the job is done and you are back on the road again.

 

[cl1986]

Has anyone changed out the rear with level control?? Do the passives still have level control or are they just normal struts.

I would hate to have the car sagging when replaced with passive.

I know most people say u dont need the air strut, but come on, even with low pressure its still holding the car up some if not 1" o 2". Air struts are made to hold "some" weight.

Anyhow, ive seen all kinds of sagging caddies, not sure if they were passive or just worn out self leveling struts. Mostly 88-93 devilles ive seen dragging.

I actually adjusted my eldo to be about 1" higher than normal and it looks way better.

 

[91TexasSeville]

Has anyone changed out the rear with level control?? Do the passives still have level control or are they just normal struts.

I would hate to have the car sagging when replaced with passive.

I know most people say u dont need the air strut, but come on, even with low pressure its still holding the car up some if not 1" o 2". Air struts are made to hold "some" weight.

Anyhow, ive seen all kinds of sagging caddies, not sure if they were passive or just worn out self leveling struts. Mostly 88-93 devilles ive seen dragging.

I actually adjusted my eldo to be about 1" higher than normal and it looks way better.

The actual level control on 1992 and newer Eldorado and Seville is a lever action switch mounted to each side of the rear sub assembly. The aftermarket replacement rear struts do come with a connection for the compressor for 88-93 DeVille, Eldorado, and Seville (they all use the same part number in the rear). Prior to 1992, the strut works by piston back feed pressure. So to answer your question, passives don't sag as long as the compressor still works. The rear struts are "reactive" as opposed to "active".

 

[kevinrea]

hey guys...

how do you know if your car as an active or passive shock system ?
I have a 1997 eldorado, not an etc.

kevin

 

[cl1986]

so what about the ones for my 94 eldo, they have the air lines also??

 

[sjwoodruff]

OK...spoke with a rep from AC/Delco today, and he claims that 503-379 will NOT work with my '98 STS. I'm going to make one more call in the next day or two to verify this with a local Cadillac dealer and see what they say. I'll keep everyone in the loop.

 

[sjwoodruff]

Re: hey guys...

how do you know if your car as an active or passive shock system ?
I have a 1997 eldorado, not an etc.

kevin

Active

 

[sjwoodruff]

so what about the ones for my 94 eldo, they have the air lines also??

Your rear shocks should be air-equipped.

 

[Krashed989]

Ohh yeah, one thing you guys should know. When you change the rear shocks to passives, you have to look at how much clearance you have in between the air line and the tire. With the ones I put on my car, the air line was actually touching the tire. I had to take them off and make a dent in the back of the wheel well with an air hammer so that they would go in backwards. Also if you didn't get it from what you just read, yes the passives still have the level control capability. They respond a LOT slower though since they no longer have the dampering valves. Its good if you get a flat tire because the car will sense it and compensate for your doughnut by extending the shock.

All cadillacs come standard with active suspension systems, and most have the air ride rear shocks.

 

[cl1986]

Ok, im lost.

I didnt find any passive struts at gm parts direct, it only lists struts over $500 for each. Im looking for my 94 eldo, are these the same as the seville??

If so, how do i find a gm part # on the gm site?? Tried 88985526 with nothing found.