Monroe MA822 Rear Shock Install

[JimW]

On Thursday morning I drove over to Centennialman's house for a scheduled installation of new rear shocks on my car. As most of you know, my ELC has never worked, so Ian rigged up a valve to the air inlet on the shock so that it can be manually inflated.

We budgeted one hour for the work.

Step by step instructions

1. Put blocks in front of the front tires.
2. Pull back trunk liner to access shock bolts at the top of the shock tower. Remove rubber cap, use 13mm hex to remove the bolts, they shouldn't be hard to remove. Standard ratchet should do the job.
3. Jack up rear end of the car at marked jack point. Brace with jack stands if possible. We used a 2.5 ton jack with wood blocking
3. Remove rear tires.
4. Disconnect ELC air lines
5. Remove bolts at the base of the old shocks (we ran into difficulty here, I'll get to that later)
6. The rear shock will then be very easy to remove.
7. Install deflated shock, bolt the top of the shocks inside the trunk.
8. We then used an air compressor to inflate the shocks, this was a 2 person job to time it right.
9. The shock will extend down, bolt to the rear arm on each side. Use Class 5 or equal bolts, with lock ring and nut.
10. Reconnect air line
11. Reinstall tire/rim, hand tighten, lower the car and torque to 100ft/lbs
12. Replace rubber shock cover cap and refasten trunk liner.

Done.

Now, we ran into a few problems. When I originally had my shocks replaced it was done at a shop. Ian suspected they did not use OE
nuts and bolts when fastening the bottom of the shocks to the arm. In my case, they foolishly used aluminum hardware. The level of corrosion on the bolts was astounding. We sheared off the tops of all 4 bolts (both on each side) and resorted to hammering and drilling clean the fused aluminum to the steel frame. At one point we were worried that the frame itself was threaded, luckily that was not the case. These problems added 2 hrs to the original time, and I was 2 hrs late for work, luckily I have very understanding employers.

Since my shocks are manually inflatable, we did not adjust the ride height, but the car settled nicely after a drive around the block. We zipped tied the OE air hoses to the new valve stem and it seems to be holding nicely.

Thanks again to Ian for his help, couldn't have done it without his expertise.

[centennialman]

Just to correct a few items:

The control arms are made of aluminum. The bolts that the shop used were steel, but not automotive grade, and had no anti-corrosion substance applied whatsover. They were fused into the holes in the control arms by corrosion. One of the bolts was 1/2 'eaten through' where it passed through the hole. That one broke off real easy. One of the 4 simply couldn't be pounded out, and I had to drill it out, and then tap out the remaining piece of the shell. We didn't reconnect the air lines; I plugged the small hole with a wood shim which can be removed, to keep out moisture in case the ELC can be revived in the future. I just zip-tied the lines to the new filler tube on the shock to keep the old lines secured for now. This might be phase 1 of the project. I saw in another post that a similar approach had been taken. My plan would be to use small diameter copper tubing and compression fittings to extend the air lines into the trunk and 'tee' the two together with a filler valve in the center of the tee. To avoid the problem of air from one shock being forced into the other during hard cornering we should install 2 small shutoff valves on either side of the tee, so that once both shocks have the same pressure, they can be isolated from each other.

EDIT: Other stuff. The old shocks were removed with the upper mounts attached. Hence removing the 2 nuts on each mount first. The new shocks had new mounts, which were installed on the shock prior to re-insertion. Much easier with 4 hands, because one set could reinstall the nuts while the other set held the shock in place.

[JimW]

Thanks Ian!

[scottydl]

Good stuff! I added this to the Classic maintenance sticky. Jim, where do you have the air hose valve stem coming out (in case you do need to adjust the ride height)?

[JimW]

I'll take some pictures to clarify, however the stems are facing the back of the car, so if you are looking at the rear driver side, the stem is directed towards the back (trunk) of the car. Its easily accessible. I've got about 3" of ride height (with maybe about 100lbs total in the trunk and backseat right now.

[scottydl]

Gotcha. Sounds like a good setup, and no more rear end dragging on the pavement behind you.

[majoraurora]

Ok, just did mine in about 45 minutes. Some notes.

No need to remove tires and wheels. You could actually do this without jacking up the car, but it does make getting the bottom bolts easier.

10mm lower bolts
15mm Upper nut (stock)

17mm Upper Nut (Monroe): Used a 17mm impact wrench as a deep well socket and a 3/8" to 1/2" step up socket handle adapter.

Basically, flex back the trunk liner, loosen & remove rubber covers, top nuts and cone washers.

*Optional step: Jack working side of car up by the frame until full suspension travel is reached.

Loosen and remove 4 bottom bolts. Remove air lines. Compress and remove old shocks.

Remove 4 locking plates from the bottom of the old shocks, put them on the new shocks.

Attach your first shock by the lower bolts.

PUT THE FLAT TOP WASHER OVER THE THREADED TOP POST BEFORE EXPANDING THE SHOCK. Then gently expand the shock by hand into the upper mounting hole.

Use the 17mm deep socket and secure the cone washer and nut. Replace the rubber top cover.

Attach the air line and replace the trunk liner.

Repeat for other side.

Amazingly easy and makes a big difference.

My ass was losing air thru a bad billows verified by soapy water....

[Aurora40]

centennialman said:

To avoid the problem of air from one shock being forced into the other during hard cornering we should install 2 small shutoff valves on either side of the tee, so that once both shocks have the same pressure, they can be isolated from each other.

Well if they are connected, the shocks would always have the same pressure. Under hard cornering, that pressure would just be higher.

I wonder how the factory system works?

[Speed Neon]

aurora40 said:

centennialman said:

To avoid the problem of air from one shock being forced into the other during hard cornering we should install 2 small shutoff valves on either side of the tee, so that once both shocks have the same pressure, they can be isolated from each other.

Well if they are connected, the shocks would always have the same pressure. Under hard cornering, that pressure would just be higher.

I wonder how the factory system works?

thats not true. the pressure would only equalize at rest. and the lesser loaded wheel would recieve the highest pressure ( the inside wheel during cornering).

the factory air dryer as two seperate compartments for each shock with a shut off valve that prevents the cross pressuration, but always them to both be vented by the exhaust solenoid.

[Aurora40]

speedneon said:

thats not true. the pressure would only equalize at rest. and the lesser loaded wheel would recieve the highest pressure ( the inside wheel during cornering).

the factory air dryer as two seperate compartments for each shock with a shut off valve that prevents the cross pressuration, but always them to both be vented by the exhaust solenoid.

Please to explain how two cylinders can be openly connected to each other, and how one can have a different pressure than the other.

If one cylinder's pressure goes up, air will move across the connection to the other until they are equal. The only way they would be unequal is if the flow rate of the connection was small and the rate of air being displaced was dramatic. They would still equalize eventually though and would not require the the cylinders to return to their initial state (i.e. the "come to rest" part you describe for turning).

[centennialman]

Hard cornering loads up the outside wheel (increases pressure in the outboard shock), and deloads the inside wheel (decreases pressure in the inboard shock). Ideally, you would like to further increase pressure in the outboard shock to assist in counteracting the lean (futher dropping pressure in the inboard shock would help too). However, if the two shock air chambers are linked together, the opposite will happen: higher pressure air from the outboard shock will flow to the lower pressure inboard shock, and make matters worse.

I don't pretend to know how the factory system operates, but we aren't talking about that here. That's why I want to isolate the shocks from each other, but still have a way of making sure that they both have the same pressure when the car is sitting level before closing the line to each.

[55624096]

Since the air in your shock system is compressable there will be a short delay in transmitting the increase in pressure above the piston of the compressed shock to the piston of the decompressing shock. However since the pressure wave travels at the speed of sound it would not be a noticable delay. This effectively gives you a Palcals law situation wherein any change in pressure is distributed equally to all pistons in your system. Meaning that both shocks will see equal pressure in a sharp curve situation. Don't think you need to isolate each side.

[centennialman]

55624096 said:

Meaning that both shocks will see equal pressure in a sharp curve situation.

Exactly my point. You don't want this to happen, because it will increase body lean. You want the outboard shock to have higher pressure, the inboard shock to have lower pressure. That's what would happen if the two chambers are isolated.

[majoraurora]

centennialman said:

55624096 said:

Meaning that both shocks will see equal pressure in a sharp curve situation.

Exactly my point. You don't want this to happen, because it will increase body lean. You want the outboard shock to have higher pressure, the inboard shock to have lower pressure. That's what would happen if the two chambers are isolated.

Gentlemen: The effects are negligable at the speeds an Aurora corners at so just keep them balanced or whatever is easiest. These are not 4000lbs sports cars.

[55624096]

Majaurora has a thread closing observation, These are not sports cars, they are awfully heavy on the front and corner like a show plow. It really doesn't make much difference how the rear shocks are configured or pressured, the car will still handle like a bull dozer. It was designed for turnpike crusing and it does that very well.

[JimW]

...until you drive an Aurora with a nicely upgraded suspension system. Centennialmans' 3.5 is well on its way. Its the best handling Aurora I've driven.

As for the project intended for my car, once its done I'll report back with some information.

Ian...maybe we get a G-meter in the car and find out what's what

[Custom88]

55624096 said:

Majaurora has a thread closing observation, These are not sports cars, they are awfully heavy on the front and corner like a show plow. It really doesn't make much difference how the rear shocks are configured or pressured, the car will still handle like a bull dozer. It was designed for turnpike crusing and it does that very well.

I highly disagree. The rear shocks have a MAJOR impact on the ride and handling of these vehicles. The rear shocks on my mom's 00 SSEi were blown and the car handled/rode like a couch on wheels. With new/stiffer rear shocks, the car handles much better. The rear shocks really do make a huge difference in the handling of the vehicle even though you wouldn't think they would.

[aurorabrain]

So we're discussing how wonderful the monroe replacement shocks are? Has anyone used the newer Cadillac DTS or Buick Lucerne rear shocks? They are much larger and fit into the same space, they also have a better ride.

[Aurora40]

centennialman said:

Exactly my point. You don't want this to happen, because it will increase body lean. You want the outboard shock to have higher pressure, the inboard shock to have lower pressure. That's what would happen if the two chambers are isolated.

Sure, if they are isolated then that's what would happen. I wasn't trying to say anything was the solution for anything. Just that if they are open, what you'd initially described wouldn't happen.

So if the factory system isolates the sides and does what you are saying is desirable, wouldn't it make sense to just fix the factory system?

As an aside, am I the only one who likes the stock ride on these cars? It's decently firm, enough that I can toss it in turns and not feel like it'll flip over. But it's quite comfortable the rest of the time.

[centennialman]

Geez, guys. I wasn't trying to start a big controversy here. And, this wasn't even done to my car! It was Jim's. I do have the MA-822s, but they are hooked up to the factor ELC. My personal preference is for a firm ride and since I am pretty much the sole occupant (global warming not withstanding) I set it up to ride like I wanted to the extent that I could afford it. Maybe no one else would like how it handles, but I thought that we can at least share our experiences.

[Custom88]

aurora40 said:

centennialman said:

Exactly my point. You don't want this to happen, because it will increase body lean. You want the outboard shock to have higher pressure, the inboard shock to have lower pressure. That's what would happen if the two chambers are isolated.

Sure, if they are isolated then that's what would happen. I wasn't trying to say anything was the solution for anything. Just that if they are open, what you'd initially described wouldn't happen.

So if the factory system isolates the sides and does what you are saying is desirable, wouldn't it make sense to just fix the factory system?

As an aside, am I the only one who likes the stock ride on these cars? It's decently firm, enough that I can toss it in turns and not feel like it'll flip over. But it's quite comfortable the rest of the time.

I love the stock ride too. The only thing I don't like about the stock suspension is its durability, but it may be average suspension life in general. The suspension on these cars don't seem to last over 80k miles, maybe aftermarket replacements wouldn't fare any better, I'm not sure though. The monroe's, to me, seem like a very decent replacement for the stock shocks. They feel like they're built much better, for a lot more of a reasonable price. .

[centennialman]

Two things:

Checked the price of the Lucerne shocks at Rockauto, and the're at least $300 for the pair (AC-Delco). Same for the DTS. Maybe they can be had cheaper, but that's a lot to pay for a pair of shocks.

Second thing:

JimW kindly let my try his classic (my first time in one); we went to look at a damaged 1st gen that I had spotted the other day - that's another story. Have to love the interior of the Classic and the instrumentation, better than the 2nd gen IMHO. Very smooth rattle free ride. As others have stated, a Turnpike Cruiser. The whole cockpit just seemed more intimate. The classic gives the impression of a big, solid road machine (which I guess it is).

Other impressions: steering had less road feel, and his exhaust is not subtle - it turns heads coming off the line. I like it!!

I don't know what the MA822s did for the ride on this car compared to its previous shocks, but it certainly hasn't made it too firm, if that's a concern.

Third thing (I can't count). There was an allusion to some kind of 'armoured' option to the DTS, because there are struts listed for that config. Can you buy an armoured DTS? (wrong thread for this I'm sure).

[JimW]

They feel like they're built much better, for a lot more of a reasonable price

That is why the Monroe is the preferred realistic replacement option.

Ian, thats a good analysis. One thing is for sure, the 2nd gen and the Classic are very different cars, frankly I think the namesake is the only thing that links these two cars together (other then a few exterior design cues)

Anyway....

[aurorabrain]

The DTS is used by the government and in limo configurations. You can get them with 3/4 ton truck brakes on the front, which would be needed for a heavy car. You can get Lucerne rear air shocks dirt cheap from salvage yards off new wrecked cars. I will make it a point to post a picture in the near future.

There is really nothing mechanically different from a '99 Aurora to an '01 Aurora. All the suspension parts will interchange/bolt on.

[luvmybravada]

I just replaced mine today. What an incredibly easy job. The car rides sooooooo much better now. Having new shocks on the rear let me know how much I now need new struts on the front.

[Rocinante]

I replaced my rear shocks today, and put the parts in the same way the old ones came out. I think I may have copied someone's previous mistake....shouldn't the washers cup/surround the top rubber mounts? It looks like the rubber should be sitting on the bottom washer, but in my case there is a space since the bottom washer is facing "down". Can someone confirm?

[Rocinante]

Apparently, the guy at the parts counter was wrong. The top washer sits "upright" on the mount (like a saucer), and the bottom one that sits on the shock is "upside down". At least, that's how it was done in another rear shock write-up:

aurorah.proboards.com/index.cgi?board=Zoom&action=display&thread=17426



And, for what it's worth, here's another link on rear shock replacement:

aurorah.proboards.com/index.cgi?b....ad=19677&page=1


My only remaining question...per the photo link below, shouldn't there be something in between the bottom washer and the bottom of the rubber mount? It seems like there should be another piece so that the entire bottom surface of the rubber mount is supported.

yfrog.com/mrrearshockj

[Randy T.]

Some good air suspension info linked below. FYI they switched the color of the Monroes from white to black. So if you want a different color it's time to warranty them. Mine were only 3-4 years old, but it improved my ride quality quite a bit when I changed them.

aurorah.proboards.com/index.cgi?action=display&board=nextgeneration&thread=22907&page=1

[sall]

Anyone have torque spec for the middle 17mm nut on the MA822 shocks?


Pic borrowed from other writeup.

FSM has torque specs for the upper mount(15 ft lb) and the control arm to shock(18 ft lbs.), but cannot find the torque spec for the middle 17mm nut in my paper manual or the software. I just tightened them down good for now. Thanks!

BTW, ride is definitely better! Mounts were shot too.