Questions on replacing my MGM shocks...

[RobH]

I have a 2006 Mercury Gran Marquis LS with rear air springs and the Handling and Performance Package. The car has 95K miles and is beginning to get bouncy. I believe that I need new shocks. I have installed many sets of shocks over the last 50 years. I have the Factory Service Manual (FSM).

The rear shocks appear to be straight forward.

The front suspension has upper and lower control arms on each side. The front shocks look to have the front spring as part of the "shock/spring" assembly. I can see where a plate at the top of the spring/shock assembly is retained with three nuts on studs on a casting attached to the frame rail. So far so good. I can see where the top of the shock attaches to the center of the plate. It looks like the plate on which the bottom of the spring is seated is attached to the shock's reservoir housing. It looks like the force of the spring is transmitted to the lower control arm through the shock reservoir housing and the single (hefty) bolt that connects the bottom of the shock to the lower control arm.

Is this all correct?

According to the FSM I have to take apart the whole front suspension on each side; i.e. remove the brake caliper, brake disc, stabilizer bar link, the wheel speed sensor wiring harness from the wheel knuckle, and remove the upper ball joint nut. Then I can spread the control arms and remove the shock/spring assembly.

Is my understanding of the front suspension work correct?

I'd like to go to the Monroe Crown Vic police shocks. I plan to get the Monroe Magnum Severe Service rear shock #550018,

http://www.oreillyauto.com/site/c/detail/MONJ/550018/03415.oap

and the Monroe Magnum Severe Service front shock # 553001,

http://www.oreillyauto.com/site/c/detail/MONJ/553001/03415.oap

I know that I will have to compress and remove the front springs from the current front shock/spring assemblies and move them and mounting hardware to the new front shocks. I live in south Texas with no exposure to salt. Am I likely to need a parts kit for the front assemblies or can I probably reuse my current eleven year old parts with 95k miles? I know that the FSM specifies for certain nuts and/or bolts to be discarded on removal and replaced with new.

Or should I go for a new complete shock/spring assembly? I would, but I can't find one for the Handling and performance package. The Monroe "Quick Strut" appears to be for standard Crown Vics, Mercurys, and Lincolns. I want to keep the stock height for ground clearance in normal driving.

Does it sound like I have a reasonable plan? Please advise.

Thanks in advance for sharing your knowledge and experience. Rob

[Curless]

Yes you can replace your rear shocks as per any other shock you have ever replaced. The front are struts, you remove the strut as an assembly and then compress it in a strut compressor to remove the strut itself. You should be able to use all of your factory hardware especially since there is no salt in your area. However, remember heat plays the same role in the wear and tear of cars. Your car is approaching 15 years old... things wear out. If you are keeping it for a while yet just buy the parts and do it once. DO NOT ATTEMPT to remove the spring without a proper compressor... yes it can be done, so can trips to the ER... if you don't have a strut compressor take the assemblies to a midas / tuffy / repair shop... I'm sure someone in your area with switch them out for you at a minimal cost. It's not worth the risk to f around trying to do it yourself.

[Mr. Man]

Yes you can replace your rear shocks as per any other shock you have ever replaced. The front are struts, you remove the strut as an assembly and then compress it in a strut compressor to remove the strut itself. You should be able to use all of your factory hardware especially since there is no salt in your area. However, remember heat plays the same role in the wear and tear of cars. Your car is approaching 15 years old... things wear out. If you are keeping it for a while yet just buy the parts and do it once. DO NOT ATTEMPT to remove the spring without a proper compressor... yes it can be done, so can trips to the ER... if you don't have a strut compressor take the assemblies to a midas / tuffy / repair shop... I'm sure someone in your area with switch them out for you at a minimal cost. It's not worth the risk to f around trying to do it yourself.He speaks the truth.

[RobH]

Thank you. I'll give Midas a call. I used a spring compressor on the front springs when I put police car springs under our 1995 Buick Roadmaster to lift it about 1.5 inches. It worked out well. But I was aware of the energy stored in the compressed springs. I felt like I was handling a hand grenade.

If I can get someone to switch the springs for me that is the route I'll take. I'd like to go with the Monroe severe duty front shocks instead of what appears to be lighter duty shocks in the Midas "quick strut".

It might make more sense to describe what we have as a coil over shock, since they are removed and installed as a unit, and they do not have the same usage as a MacPherson strut. But, maybe they are a different member of the "strut" family, a sibling of the MacPherson strut. My 2006 Ford Crown Vic/MGM Workshop Manual calls it a "Shock Absorber and Spring Assembly". It has two sections on them, one for removal and installation of the assembly, and a second for disassembly and assembly of the assembly.

Thanks again for the advice.

[Mr. Man]

KYB also makes a shock you can use.

[1Marauder]

He speaks the truth.



All above +3.

I always buy the "bushing kits" that come as a small additional cost to go with the struts/shocks.

KYBs I believe to be slightly firmer than Monroe Servere duty. I am not stating that this is desirable, as firmness is a preference. I've done KYBs and prefer the KYB in rear, however, I may put Monroes SD in front on next car... But alas, I am older.

[RobH]

...But alas, I am older.

Thanks for the input. Alas, I am older also. And my wife and my brother's wife, who are why I will probably go with closer to stock components instead of the performance parts I would install for myself.

Oh well. Life is still good. :)

[1Marauder]

Thanks for the input. Alas, I am older also. And my wife and my brother's wife, who are why I will probably go with closer to stock components instead of the performance parts I would install for myself.

Oh well. Life is still good. :)

Good! Like I said, the SB KYB's are a little firm. I am hoping they are going to soften up a little.

[Mr. Man]

Sachs may still make a direct replacement OEM style. Finding an auto parts store that can get them might be the challenge.

[Griso8v]

Rob may want to consider Bilsteins if they make it for that car. I put them on my 1995 Crown Vic (Police Package). They were on for at least 100K before I sold the car with no perceptible loss in performance, just like they claimed. Monroe is ok, KYB better but the Billies are well above. Good luck.

[massacre]

Aero Vic suspension and MM suspension are a lot different
Just sayin

[RobH]

No Bilsteins available. I've been waiting for them to come out. Probably never will. I put Bilsteins on the wife's 1995 Buick Roadmaster, along with the Chevy cop car springs, and they were still fine 100,000 miles later when it got totaled and replaced by the MGM with the handling package.

Front shocks/spring assemblies on the MGM are for sure harder to do than shocks on the earlier design. 2006 MGM rears are easy to access the top of the shock. On our 1995 GM sedans, it was a pain to get to the rear shock top nuts. I've done the rears on the MGM and one of the fronts. The front was not as easy the factory shop manual made it seem. I'll post when I'm finished, hopefully in a couple of days.

As always, it would be easier with a hoist and another pair of hands to help from time to time.

[MyBlackBeasts]

Don't even bother with spring compressing etc.

Just get coil-overs and replace the worn out spring too. No extra labor/time/hassle. Easy swap, no future hassles when spring pukes and you have to pull the thing completely apart again.

http://www.oreillyauto.com/site/c/detail/MON2/171346/03415.oap?year=2006&make=Mercury&model=Grand%2BMarquis&vi=1432101&ck=Search_C0077_1432101_-1&pt=C0077&ppt=C0035