Koni FSDs - Get 'em

figurefive

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2010 Mazda 5 Grand Touring
My wife's '09 Mazda 5 GT had developed a clunk and a bit of an unusual shimmy/wiggle in the rear. With 60k miles on the odometer I figured it was a good time to put on some new shocks and sway bar bushings. Turned out I was right as upon removal I found the right rear shock had blown and was oozing grease onto the inner shaft.

I've been running FSDs on my VW R32 for 4 years and love them, so when my research showed that the FSDs for the Mazda 3 would work on our 5 I picked up a set (great price from THMotorsports here). Koni part number is 2100-4045.

The DIYs I found floating around the Internets combined with the similarity in design to my VW's Macpherson front suspension made the install a breeze. One thing I'd suggest for you Mazda guys that I didn't find in any of the DIYs is to fashion yourself a front strut spreader tool out of an 8-10 mm hex socket. Use a Dremel to grind it down into an oval and it will fit into the small gap just below where the strut sits in the steering knuckle. Give it a 90 degree twist with your socket wrench to open the knuckle and make pulling the strut out considerably easier. I had one from my VW install and it worked wonders.

The only hiccup I encountered was the threads on the rear shocks wouldn't take take the bolts from the Mazda's shock mounts. I had to run to Home Depot to pick up a couple of 8mm x 1.25 thread pitch nuts and lock washers.

With the FSDs the car rides so much smoother and flatter than it did stock. Even my wife (who is not a gear head or car girl in any way) could feel the improvement. The new sway bushings eliminated the clunks we had, so it rides like it's a new car once again.

If you're looking to replace your shocks/struts I really don't think you could do much better for this car than the Koni FSDs.
 
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Did you get the "heavy duty" versions spec'd for the Mazdaspeed3? They're valved a little stiffer.
 
Did you get the "heavy duty" versions spec'd for the Mazdaspeed3? They're valved a little stiffer.

The Koni product number for Koni FSD for 2010+ Mazdaspeed3 is 2100-4039. THMotorsports list price for this FSD kit for Mazdaspeed3 is $688.80

http://thmotorsports.com/koni/koni_fsd_shock_kit/21004039/i-104507.aspx

I pulled the part number from Koni's website which returned 2100-4025, so that's what I searched to make the purchase. Does the 5 come with the stiffer springs from the Ms3 to account for the heavier weight? Even if that's the case the set that I got is working great. While I might appreciate a tad more stiffness, I'm not sure the wife would. Wife happy = hubby happy.
 
I had an FSD go bad within a year on the back driver's side. Just an FYI. I think all shocks are going to be taxed by the heavy ass rear end on these cars.
 
I had an FSD go bad within a year on the back driver's side. Just an FYI. I think all shocks are going to be taxed by the heavy ass rear end on these cars.

Did you have it replaced under their warranty, or replace the dampers with another brand? If the former, have you had any other failures?

I've been considering the FSDs myself.
 
Anything can be broken. Does not mean its inferior product but there are a lot of factor can make it defective. As long as the company back it up I have no concern.

BTW: Annual Koni 25% off sale are going on now. You probably could get FSD or sport for %450-500 for a set.
 
Another failed Koni FSD being replaced under warranty. Faxed in the claim today.

Replaced left rear a few months ago. Oil on the garage floor under the right rear now.

I cannot recommend these shocks for the Mazda 5, at all. I have to drive 600 miles to come back and deal with this crap, so not happy at all with Koni.
 
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