Bilstein B4 and OE strut bearing

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2008 Mazda5 GT
Installed new Bilstein B4s. Awesome ride, definitely stiffer not just b/c they are new compared to tired old struts.
Couple of devil in the details for future reference, which Im surprise no one has mentioned before

-The design of the OE strut base is superior to B4s. The OE base has a raised ring/lip to fit square into the knuckle. The B4 has a tiny bead weld that you must make sure dont get tucked into the knuckle. If not careful, you may install them lower into the knuckle then intended that little nub serves a purpose.
-OE strut uses a longer alignment tab with a curved/hook opening to allow the knuckle bolt to pass through. The B4 alignment tab just abruptly ends short. Its long enough to ensure alignment, just shows the aftermarket-ness.
-OE strut uses a hard dust cover that is sized to fit over the body AND sized to fit/reuse the OE dust boot. The B4 hard dust cover is small and short and is not wide enough to fit the OE dust boot. You need to mod the OE hard dust cover if you want to reuse it. I wrapped duct tape to make the B4 body a little thicker (this tells me the OE strut body has a larger diameter), then drilled 4 holes on the sides, at the very top of inside channel, to allow water to drain. Will fit as tight as how many rounds of duct tape you apply.
-Between Moog vs Monroe, I opted to try the Monroe strut bearing. Comparing Monroe vs OE strut bearing, I feel the design of the OE strut bearing is FAR superior. It has alignment notches to fit into the top of the strut tower. Most important, the casing and how it is seals is better. Returned the Monroe and opted to rebuild the OE strut bearing.
FWIW, unless there is physical damage (ran super dry where the balls left groves on the race), the strut bearing is very easy to rebuild. One tip I recommend is to BE VERY CAREFUL and avoid using a magnetic pick-up tool on any of the 36 tiny balls. The magnetic may leave the balls magnetized and cling tiny metal/debri on it. You must pack the new bearing inside to avoid moving air. Soak the bearing cage, balls, and race in brake fluid and use a clean tooth brush to clean the bearing cage and housing thoroughly. Apply new grease and it is good to go! Its really that simple and it is a much better quality/design bearing than aftermarket.

Sorry, dirty hands so no pics If anyone else installs B4 or decides to rebuild their OE strut bearing, post some pics for reference. I failed to measure the piston travel. Hope someone can note that.
 
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2010 Mazda 5 Sport
When you say "Strut Bearing", is that the bearing in the "Strut Bushing" that goes beneath the Strut Mount?

Mazda part number: C273-34-38XB ($26 at "Real Mazda Parts")

I just ran into that mess today. Just got a nice used 2010 Mazda 5 with the notorious front end clunk. Got the Strut assembly out...compressed the springs...pulled off the strut mount from the top and the bushing/bearing came apart in half. Ball bearings everywhere. Was not happy that I have to put this on hold until the part comes in.

-Mike
 
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2008 Mazda5 GT
When you say "Strut Bearing", is that the bearing in the "Strut Bushing" that goes beneath the Strut Mount?

Mazda part number: C273-34-38XB ($26 at "Real Mazda Parts")

I just ran into that mess today. Just got a nice used 2010 Mazda 5 with the notorious front end clunk. Got the Strut assembly out...compressed the springs...pulled off the strut mount from the top and the bushing/bearing came apart in half. Ball bearings everywhere. Was not happy that I have to put this on hold until the part comes in.

-Mike
Yes, we are talking about the same thing. Hopefully you bought OEM or if you manage to pick up all 36 balls, just clean it with brake fluid and brush. Don*t need too much grease, just smother inside of the race, to cover the ball cage and balls.
 

phunky.buddha

Booga Booga?
:
DFW TX
:
No mo MZ5 want MX5
I bought a new set on eBay for $30 shipped, both top mounts including bearings. Way easier than trying to find all the pieces of my busted up OEM top mounts...
 
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2008 Mazda5 GT
Hey man, out from the woodworks!

Money solves all problems but no reason to reuse what you can. Plus, serves the user well to understand how things work.
 
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2010 Mazda 5 Sport
Yes, we are talking about the same thing. Hopefully you bought OEM or if you manage to pick up all 36 balls, just clean it with brake fluid and brush. Don*t need too much grease, just smother inside of the race, to cover the ball cage and balls.

Yeah, it's Mazda parts. Everything comes in Mazda packaging. I don't try to trust the Autozone stuff if I can help it.

It was 90 degrees so I was working in the shade in the grass...the balls are somewhere in the lawn :) At 90k miles...just better to replace with new.
 
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MX-5, Mazda5
Hows the ride been after a few miles? Also wondering if you bother to load the suspension when you tightened those lower bearings? I might have read that they could bind up if torqued at full droop.

thanks
 
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2008 Mazda5 GT
Hows the ride been after a few miles? Also wondering if you bother to load the suspension when you tightened those lower bearings? I might have read that they could bind up if torqued at full droop.

thanks
I may be bias bc I*m a Bilstein fanboi but seriously they are fantastic. Check out AJUSA for great prices, almost the same as KYB Excel (fka GR2). For the record, KYB *bodies* are more accurate to OEM spec/detail, where as the Bilstein is more aftermarket. But what you pay for is the inner working (quality fluid, shim stack, and fluid control).

I*m guessing you are asking about rear *lower* shock bushing? I preload before tightening by using a block of wood on a scissor jack and raising it up to hold the axle taut. If left at full drop and tighten, there*s awkward movement if not held steady. All suspension components should be tighten under load.
 
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MX-5, Mazda5
I am a Bilstein fan myself. I have the DFV coilovers with RB stabilizers on my MX-5. Its an excellent pairing for a street car.
I should probably not rule the B4 out just yet. You said the H&R springs aren't a good match for the B4, and that may be true. Do you know of an alternative spring set that will give me a little drop while still performing better than stock?

And yes, I did mean lower bushings. I used the same method you did on my MX-5 coilover install. Just curious if it was general knowledge or not.
 
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2008 Mazda5 GT
I am a Bilstein fan myself. I have the DFV coilovers with RB stabilizers on my MX-5. Its an excellent pairing for a street car.
I should probably not rule the B4 out just yet. You said the H&R springs aren't a good match for the B4, and that may be true. Do you know of an alternative spring set that will give me a little drop while still performing better than stock?

And yes, I did mean lower bushings. I used the same method you did on my MX-5 coilover install. Just curious if it was general knowledge or not.
Love the '13 Club edition but don't they come with a sportier Bilstein suspension package?(scratch) The Ohlins are quite a few steps above.

BTW, Miata Is Always The Answer, not MX-5... Let the Europeans keep their infatuation with cars as alphanumeric letters. US will keep the Miata namesake.


The only thing I've come across are a pair of Euro spec'd Eibach Prokit springs that offer a modest ~<1" drop for the Mazda 5 1.8 (or was it 2.0) and diesel engine; two different sets. The diesel's weight is close to the us 2.3 BUT you cannot buy either in the US. A Euro member brought this up in the past, you'd need to search the archives for ref and part number. Personally, I would LOVE to pair the diesel Eibach Prokit with B4s. I think the H&R Sport, being a bit lower and stiffer, will likely wear out the B4 sooner (*cough* limited lifetime warranty)... A lot of this depends on how/where you drive (fully loaded vehicle and rough roads at high speeds or not) and what you can tolerate.

B4 - twin tube, meant for OEM replacement and tad stiffer
B6 - inverted monotube strut front + standard rear shock, meant for street/sport springs
B8 - inverted monotube strut front + standard rear shock with shorter piston, meant for race springs
 
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phunky.buddha

Booga Booga?
:
DFW TX
:
No mo MZ5 want MX5
Hey man, out from the woodworks!

Money solves all problems but no reason to reuse what you can. Plus, serves the user well to understand how things work.

:D

Totally agree- but my stock upper mounts had been sitting on the garage floor for so long that I had no idea where all the little ball bearings went. Way safer to go with new ones than try to pretend half the balls were good enough on that bearing. :)
 

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