Rear Shock Absorber Question

[Quist22]

Hey everyone. I wound up getting this resolved. The shock on the driver side was bad. When I removed it it had loose parts rattling around inside it and you could extend and compress it with barely any force. I was able to return them to napa and get my money back which was awesome. I normally buy parts off rock auto but I’m glad I bought these at napa as I have no idea how returning them to rock auto would’ve went.

I replaced these with Monroe ma822 so we’ll see how long those last. So far they don’t rattle. The rear end still makes some noise but no rattling so I’m good with it. Vehicle stability seems to be resolved also as the car doesn’t skirt when hitting bumps anymore.

Thanks to all for the help.

 

[G-784595]

Hey Everyone. I recently replaced the rear shock absorbers on my 2004 park avenue. The oem one on the passenger side started leaking oil so I replaced both of them with KYB SR1002. Removal and install went fine with no issues. However, after install the rear end make a thumping sound every time I hit bumps. It sounds very similar to if you were to knock on the spare tire cover in the trunk, so I removed that hoping that's all it was and the sound is still there. I checked the rear end suspension with the car on the ground to see if I could notice anything loose, nothing appeared to be loose. The nut on the top of the shock seems tight when on the ground. I am wondering if anyone has run into this with aftermarket shocks before? I kept the oem shock mounts in there as they looked fine visually, could the shock mount be the issue, maybe I need KYB mounts? The car also "skirts" to the driver side pretty bad if you hit a bump on the highway or going at faster speed, which makes me think the shocks aren't doing there job. They seem to fill with air fine, I hear the compressor run and then shut off time to time. I am also wondering if maybe the shocks are stiff and need breaking in? I haven't replaced a whole lot of shocks before so I don't have a ton to go off of from past experiences so any insight is appreciated. Thank you!

Yes you absolutely need to change the mounts & all other bushings you wouldn’t believe how loud a small amount of shrinkage on the rubber bushing can make when they get old & hard from age & heat & get as hard as a brick the don’t flex well !Then they start to crack & the stiffness causes all kinds of other issues but the main reason you don’t want any movement in any of these parts & the rubber should be pliable & flex & soak up vibrations & stuff ! When they get hard they seem to distribute the load correctly anymore & because of the stiffness the vibration transmits into the body of the vehicle body & also because there isn’t any flex anymore with the rubber part thats bonded into or together with the steel-it starts cracking/splitting & it gets fatigued & the mounts become unbound or unvulcanized causing issues like yours ? I’ve changed out struts on numerous vehicles where by all appearances the strut/shock mounts looked just fine initially & it wasn’t until they were disassembled that I saw where the problem & the noises had been coming from ? I especially urge you to change them with new if the vehicle is over 10-12 years old & has over 100K miles on the OD & or has been subjected to harsh roads & or extend weather conditions? Also if the vehicle has been in an accident or the shock/strut that was in there was left in dis-repair & for a lengthy time period as this could have distorted the mount in some manner ? Most strut mounts these days aren't to expensive now that we have an influx of fairly well made Chinese manufactured mounts being imported so reasonably priced ? It’s the materials that they are made off that is questionable ? But, as a rule of thumb change out your mounts on all suspension upgrades & or repair/replacements & you will be fine. And especially if your doing someone else’s vehicle you wouldn’t want to disappoint your friend or customer with a return on the repairs & them hearing weird noises & such like & unhappy or dissatisfied with your work ! I just found this thread & thought I would reiterate what I have learned in my 35+ years of repairing things ? I hope you found your noises & that you were able to fix the issue & this helps out both you & others folks with similar issues & problems !
Have a great day !
Sincerely & Respectfully !
John

 

[Lui]

Hey Everyone. I recently replaced the rear shock absorbers on my 2004 park avenue. The oem one on the passenger side started leaking oil so I replaced both of them with KYB SR1002. Removal and install went fine with no issues. However, after install the rear end make a thumping sound every time I hit bumps. It sounds very similar to if you were to knock on the spare tire cover in the trunk, so I removed that hoping that's all it was and the sound is still there. I checked the rear end suspension with the car on the ground to see if I could notice anything loose, nothing appeared to be loose. The nut on the top of the shock seems tight when on the ground. I am wondering if anyone has run into this with aftermarket shocks before? I kept the oem shock mounts in there as they looked fine visually, could the shock mount be the issue, maybe I need KYB mounts? The car also "skirts" to the driver side pretty bad if you hit a bump on the highway or going at faster speed, which makes me think the shocks aren't doing there job. They seem to fill with air fine, I hear the compressor run and then shut off time to time. I am also wondering if maybe the shocks are stiff and need breaking in? I haven't replaced a whole lot of shocks before so I don't have a ton to go off of from past experiences so any insight is appreciated. Thank you!

I had that same knocking sounds with brand new rear KYB shocks. I tried everthing and could not find anything wrong mounted. After multiple disassemble and reassemble I ended up replacing them with new ACDelco. Which immediatly solved the problem.
I still don´t understand what the problem was. It must be the KYB shocks.

 

[BuickGirlFromMars]

Hey everyone. I wound up getting this resolved. The shock on the driver side was bad. When I removed it it had loose parts rattling around inside it and you could extend and compress it with barely any force. I was able to return them to napa and get my money back which was awesome. I normally buy parts off rock auto but I’m glad I bought these at napa as I have no idea how returning them to rock auto would’ve went.

I replaced these with Monroe ma822 so we’ll see how long those last. So far they don’t rattle. The rear end still makes some noise but no rattling so I’m good with it. Vehicle stability seems to be resolved also as the car doesn’t skirt when hitting bumps anymore.

Thanks to all for the help.

i never saw this reply law year, but if you still wanted to know it sounds like your original shock mounts failed and/or you didnt torque them right. if you jack up the car by the control arm and the mount is bad you may notice inside the trunk area the shock rod poke up higher if it was
Also the Kyb likely require a different spring in the compressor so the pressure is higher, but i havent checked into that

 

[Lui]

Hey everyone. I wound up getting this resolved. The shock on the driver side was bad. When I removed it it had loose parts rattling around inside it and you could extend and compress it with barely any force. I was able to return them to napa and get my money back which was awesome. I normally buy parts off rock auto but I’m glad I bought these at napa as I have no idea how returning them to rock auto would’ve went.

I replaced these with Monroe ma822 so we’ll see how long those last. So far they don’t rattle. The rear end still makes some noise but no rattling so I’m good with it. Vehicle stability seems to be resolved also as the car doesn’t skirt when hitting bumps anymore.

Thanks to all for the help.

How is the ride with the Monroes? Is it as soft as the original shocks or do you feel any difference? Like more firm or more soft? I am asking, because I like the soft ride of the original GM shocks.

 

[BuickGirlFromMars]

How is the ride with the Monroes? Is it as soft as the original shocks or do you feel any difference? Like more firm or more soft? I am asking, because I like the soft ride of the original GM shocks.

From most peoples accounts, its not as soft (as soft ride OEM) but I have not had functioning original shocks. well, ones in good shape, so I cant compare it personally. But it was sufficient to someoen who had no comparison in my opinion. I had them on my aurora. which wasnt as "soft riding" a car, and im unsure what shocks were on my 1998 park avenue but that bit the dust anyway when I ate a culvert at 55mph lol

 

[tb.dxb]

How is the ride with the Monroes? Is it as soft as the original shocks or do you feel any difference? Like more firm or more soft? I am asking, because I like the soft ride of the original GM shocks.

I have Monroes installed, last replacement some years ago. I am driving a bunch of newer cars since then, and each time driving the Buick I notice how soft it is in comparison.
So, IMO even if Monroes are a little firmer, compared to more modern cars they are still giving you a soft ride.

 

[buickace]

From most peoples accounts, its not as soft (as soft ride OEM) but I have not had functioning original shocks. well, ones in good shape, so I cant compare it personally. But it was sufficient to someoen who had no comparison in my opinion. I had them on my aurora. which wasnt as "soft riding" a car, and im unsure what shocks were on my 1998 park avenue but that bit the dust anyway when I ate a culvert at 55mph lol

Your knowledge is amazing! I have a 2000 Park Ave (std) with a rear compressor running about all the time. I replaced the air shocks with Monroes and rides great BUT the car sits up about 3 - 4" higher off the rear tires than before. I don't think this was the normal original height. The shocks replaced were original. The compressor kicks off and on occasionally which seems normal. I don't see any ride height arms that some videos show. Any thoughts?

 

[BuickGirlFromMars]

Your knowledge is amazing! I have a 2000 Park Ave (std) with a rear compressor running about all the time. I replaced the air shocks with Monroes and rides great BUT the car sits up about 3 - 4" higher off the rear tires than before. I don't think this was the normal original height. The shocks replaced were original. The compressor kicks off and on occasionally which seems normal. I don't see any ride height arms that some videos show. Any thoughts?

yours may possibly not look the same but you see the lower center part? there is a black plastic piece on a rod thats clipped to driver side control arm(rear) thats the level sensor its linked to and that rod gives the sensor the height. if its broken or misadjusted etc that can cause the problem the original shocks may have been tired. how long since you replaced

 

[buickace]

View attachment 40629

yours may possibly not look the same but you see the lower center part? there is a black plastic piece on a rod thats clipped to driver side control arm(rear) thats the level sensor its linked to and that rod gives the sensor the height. if its broken or misadjusted etc that can cause the problem the original shocks may have been tired. how long since you replaced

The shocks replaced were original. It's my 94 year old mom's car she and dad bought new in 2000. I'll check for this linkage tomorrow morning. Only 104,000 miles. On the dashboard the ABS and Trac control lights are on (but were on prior to shock replacement). I've attached a picture from earlier today on ride height.

 

[BuickGirlFromMars]

What size is that tire? 225-60-16 is the one the car came with, just making sure i ask

 

[buickace]

What size is that tire? 225-60-16 is the one the car came with, just making sure i ask

yes and the front struts never replaced

 

[BuickGirlFromMars]

yes and the front struts never replaced

it could possibly be sagging up front and making it more pronounced.

 

[BuickGirlFromMars]

D Height Measurement
The D height dimension measurement determines the proper rear end ride height. There is no adjustment procedure. Repair may require replacement of suspension components.
1.With the vehicle on a flat surface, lift upward on the rear bumper 38 mm (1.5 inch).
2.Gently remove your hands. Allow the vehicle to settle into position.
3.Repeat the jouncing operation 2 more times for a truth of ~ times

4.Measure from the front outboard control arm bolt center line to the bottom of the control arm wheel bearing and hub face in order to obtain the D height measurement.
5.Push the rear bumper downward to 38 mm (1.5 inch).
6.Gently remove your hands. Allow the vehicle to settle into position.
7.Repeat the jouncing operation 2 more times for a total of 3 times.
8.Measure the D height dimension.
9.The true D height dimension number is the average of the high and the low measurements.
10.If these measurements are out of specifications, inspect for the following conditions:
-Improper weight distribution
-Collision damage
-Worn or damaged suspension components

======================
randomly looked up the specs on an 02 park avenue(base) for this procedure / data

 

[buickace]

I don't see how damaged components would occur on BOTH sides of the rear axle. There's been no collision and I don't know what improper weight dist is or would apply.

 

[BuickGirlFromMars]

I don't see how damaged components would occur on BOTH sides of the rear axle. There's been no collision and I don't know what improper weight dist is or would apply.

there is only one point that is monitored and its on the driver side and the rear shocks are just aired up the same amount to adjust when the system, on the driver side, indicates it is low

 

[buickace]

Thank you I will take a look at tomorrow or Tuesday. I really appreciate your help BuickGirlFromMars.

 

[buickace]

As an update my mechanic said he thinks Oreilly's shipped the wrong shocks as they are stuck at full length. So I thought I would take them off today and get new ones but out of curiosity I took the air line off the shocks which lowered the car to "normal". I removed the circuit breaker #6 under rear seat to prevent adding air so now everything rides and looks normal. My question is should I reinstall the circuit breaker, turn on the car and allow just so much air in the shocks since 20 psi is the minimum? Or is it probably okay to run without air. I never haul or have anyone in back seat.

 

[BuickGirlFromMars]

As an update my mechanic said he thinks Oreilly's shipped the wrong shocks as they are stuck at full length. So I thought I would take them off today and get new ones but out of curiosity I took the air line off the shocks which lowered the car to "normal". I removed the circuit breaker #6 under rear seat to prevent adding air so now everything rides and looks normal. My question is should I reinstall the circuit breaker, turn on the car and allow just so much air in the shocks since 20 psi is the minimum? Or is it probably okay to run without air. I never haul or have anyone in back seat.

did the shocks get actuated a couple times...by hand
also your driver side control arm in the rear is supposed to have a small lever attached to it, that has a sensor that determines the height of the suspension. if the air coming out made it proper, your car thinks its low andi ts adding air. confirm if that link is there and if the sensor looks ok. if you play with the link with key on you should be able to get it to add air and stop(and even exhaust) if you are patient and wanted to see it. I would think the sensor bracket got bumped or the link is not attached.

 

[buickace]

did the shocks get actuated a couple times...by hand
also your driver side control arm in the rear is supposed to have a small lever attached to it, that has a sensor that determines the height of the suspension. if the air coming out made it proper, your car thinks its low andi ts adding air. confirm if that link is there and if the sensor looks ok. if you play with the link with key on you should be able to get it to add air and stop(and even exhaust) if you are patient and wanted to see it. I would think the sensor bracket got bumped or the link is not attached.

Well I had to pull the shock downward to initially install and pushed it back together today. Would this help add a minimal amount of air?

The ELC arm is there and okay. My mechanic said he "flipped" the arm so as not to add air? I looked and the arm elbow is pointing upward instead of down. I don't know how he "flipped" it. His thinking is this would stop air from being pumped in and maybe some of the air would work its way out to a more agreeable level but the compressor now runs 90% of the time (before I took out CB#6). I'm going to see if I can "flip" the arm down tomorrow and reinstall CB#6 and see if the proper amount of air goes in. If not I can do what I did today and live with a no air air-shock.

I honestly think my left rear tire hit a pothole pulling out of a parking lot because the car undercarriage bottomed. I read where someone else had this issue. My mechanic said there was no damage to any suspension parts and he thinks the ELC module is working based on exhausting the air.

Many thanks wondergirl for additional thoughts!