Dman302

farmington

buckmeister2

many of us use RA. They are the best, imo. If they have it, and you need it, buy it!

Dano523

Lets back up and why do you think that you need a new MRC shock in the first place.

If someone told you it was leaking and needed to be replace, then wipe the oil off the shock with a paper towel and put a refrigerator magnet to the it.
If the fluid is from the MRC shock, the magnet will stick to the towel.
Hence MRC shock fluid has iron partials in it, and this is how the shock controls the fluid in the shock.

I bring this ups since you may have fluid on shock to make it look like the shock is leaking, but bank that its not MRC fluid from the shock itself isntead.


Also, until you start the car to put power to the F55 module, the shocks will have a real soft give to them. Again, the shock dampening is controlled via the shock energizing it electromagnetic to slow the fluid down as it passes through the damper channels. Hence until you start the car, the F55 module is not powered up and the shocks will be softer than normal when the car is running isntead.


To add, somethings is not the shock the problem if not working correctly with the F55 module is powered up, but just a top shock electrical connect that is broken, just it needs to be replaced.


So before you order the new MRC shock, are you dam sure that the old shock itself has a problem to start with?

Dman302

Dano523

As stated, what fluid that your wiping away from under the boot, make sure a magnet sticks to it, to make sure its the shock that is leaking in the first place.
Hence back end can sling a lot fluids, and you want to make sure that its MRC fluid (with iron particals in it from the shock that your seeing in the first place.

As for the MRC shocks for a 05, ac-delco 580-1060 the right rear, and ac-delco 580-1059 for the left rear.
https://www.rockauto.com/en/parts/ac...+absorber,7556

Myself, for the cost that what each MRC shock costs alone, would just dump the F55 system and MRC shocks, and install either Blistein B6 or B9 shocks isntead. The F55 system is easy to program out of a BCM with a Tech II, and the Blistein shocks up with a better handling ride isntead. The B6 shocks are base car set up replacements, while the B8 shocks are as slighlty stiffer ride used on the Z51 option and Z06 cars isntead.

Hence the MRC shocks normal last about 100K, but if you have one that is giving up the ghost due to higher mileage, suspect another few to follower suit shortly after as well. Hence at $373 each, that $1500 for the set, and not really sure it worth the option on a base car to start with.

On the GS and above cars that start with a upgraded handling suspension package, the MRC/F55 system added to such really enhances that suspension system, but on the base suspension, it's more of just a softer ride in Tour setting, and most can not tell the difference in ride or handling in sports mode setting when the shock are slightly stiffer in dampening instead.

C6ToGo

If you buy from Rockauto, always seek out their current 5% off discount code. Enter 8955672981483357 in the "how did you hear about us" box.

buckmeister2

Dano is right about everything, though I disagree about dumping the F55 system. It is an original option that not a lot of cars have, and I would retain it for that reason, UNLESS you have, or plan to, change out other original components, or plan to track your car often. F55 may not have much real-world value, but it is a sought-after option. If you have it, I would keep it.

gsflyer2011

I have a 11 GS with F55 and i love it. I never track the car but when i want some very spirited driving i turn it on. Also on some really bumpy portions of I95 at hwy plus speeds it settles down all that oscillations softer setting causes. Albeit little harsher but not as much of up and down. With our tires costing $ 400 each and up and lasting 1/4 of the time of these shocks, when they go they will be replaced with same. I really like them, they transform the car, it us like having two suspension systems in one car. I am also very happy that they came way down in price, from $1000 each to present. 4k would have been a serious decision for the bilsteins. I am very glad i specified that option when i ordered the car back in 11.

HOXXOH

The reason F55 is a sought-after option is that it's superior to hydraulic shocks due to being able to instantly adjust compression and rebound based on road conditions. The expected life is 150K miles or more, since only the seals wear out and cause leaks. Being different than shocks that decline in ability starting on day one, replacement mag shocks can be installed individually vs in pairs.