[Estblue340]

Hi everyone,

i did a quick search but could not find a post about my specific problem,

I'm currently driving a 2018 F30 BMW 340i Xdrive with Dinan coils spring set combined with F80 bump stop. I’m running MPPSK from factory

The coils spring have been on the car for roughly 10 000 miles. I recently went to my local dealership (which is not an authorized Dinan dealer) because the car is making weird clunking noise when hitting small bump on the road. The technical advisor informed me that the front left side strut mount bearing was broken and needed to be replace. According to him, this is due to the fact that the shock absorber is too long compared to the coil spring. As a result, the top of the coil spring does not reach the strut hat which would cause the premature failure of the strut bearing. For reference, the vehicle has 17,500 miles. I was very surprised to hear that the problem would be caused by a Dinan part. FYI, the vehicle has no other suspension or wheels modification.

Since im no mechanic and my knowledge on the subject is somewhat limited, i'd like to know if it their explanation make sens (or if the failure has nothing to do with the lowering spring). Luckily, they will replace the strut bearing on warranty, but if the probleme reoccur for some reason, it will be at my expense...

Thank !

[exE36M3]

Do you have the electronic dampeners aka EDC / adaptive suspension?
But as an side, visit these youtube videos and see if your noise is like this...

Noise

Because the clunking that sounds like a suspension is A LOT of times, the stupid power steering racking block/spring bouncing around.

I'd suggest letting BMW do their fix (after all, it's free) but if the noise returns, it's this.

[FaRKle!]

I'm not sure what the SA means by "strut mount bearing." Is he referring to the top mount where the damper piston shaft bolts to the top mount, or is he referring to the thrust bearing that the spring seats against up top on the top mount?

Did he show you the car up in the air that he was able to rattle around the spring because it wasn't loaded? You can also jack your car up via the front center jack point till the front suspension is hanging all the way and see for yourself if the spring is loose. If it is, then that's a Dinan problem (and a pretty significant one at that).

[cfm56d7b]

Did a Dinan-authorized shop install the springs?

[Estblue340]

Originally Posted by exE36M3

Do you have the electronic dampeners aka EDC / adaptive suspension?
But as an side, visit these youtube videos and see if your noise is like this...

Because the clunking that sounds like a suspension is A LOT of times, the stupid power steering racking block/spring bouncing around.

I'd suggest letting BMW do their fix (after all, it's free) but if the noise returns, it's this.

Yes i have the EDC suspension. i didnt notice that kind of clunk when turning the steering. but if the noise persist i'll make sure it's not the steering rack, Thank !

[Estblue340]

Originally Posted by cfm56d7b

Did a Dinan-authorized shop install the springs?

No, since the closest Dinan dealer is like 200 miles away, an independant shop did the install.

at first i thought they might have mess with the install, but the SA at BMW told me that the Dinan part is the reason why the strut bearing failed .. which i honestly doubt since so many people on the forum have been running these spring for years without any issues ..

[Estblue340]

Originally Posted by FaRKle!

I'm not sure what the SA means by "strut mount bearing." Is he referring to the top mount where the damper piston shaft bolts to the top mount, or is he referring to the thrust bearing that the spring seats against up top on the top mount?

Did he show you the car up in the air that he was able to rattle around the spring because it wasn't loaded? You can also jack your car up via the front center jack point till the front suspension is hanging all the way and see for yourself if the spring is loose. If it is, then that's a Dinan problem (and a pretty significant one at that).

to my understanding, he was referring to the thrust bearing that make the spring rotate when you turn the wheel. i did not see the car up in the air, but they should receive the replacing part by the end of the week, so i will get another appointment in the next few days. i'll make sure to go have a look while the car is in the air et take some photo / video of the car to show you what is the actual problem.

Thank for your help !

[Stlblues]

Originally Posted by Estblue340

No, since the closest Dinan dealer is like 200 miles away, an independant shop did the install.

at first i thought they might have mess with the install, but the SA at BMW told me that the Dinan part is the reason why the strut bearing failed .. which i honestly doubt since so many people on the forum have been running these spring for years without any issues ..

I tend to doubt it's the springs as well given Dinan indicates you can run them with OEM struts and so many people run them that if the springs were defective it would be widely known by now. I have essentially the same set up as you but my car is a year older and has 30k miles on it. I'm in to hear what you find.

[therealm3]

I am interested to hear what you find as well. I am trying to diagnose a similar drivers side knock/clunk and after reading threads here and watching some of those you tube videos, I am thinking it may be the steering rack.

[Stlblues]

OP - any update on this?

[Estblue340]

Originally Posted by Stlblues

OP - any update on this?

Sorry for the delay. i've been out of town lately.

so here a quick update.

i've got the whole stut mount replaced on both side under warranty last week. i took somes pictures and the bearing were clearly shot. However, the coils were not "hanging loose" on the strut as the SA initialy told me. The tech had to use a press to swap the strut mount. He said that even if the coil was way more easy to rotate with the dinan part that with the OEM coils (maybe its normal since the coil is shorter .. ?).

i've send pictures of the part to Dinan and the customer service told me that "they had some reports of issues with the springs not seating properly in the perch, and this seems to be the issue here". They are sending me rightaway a replacement part, free of charge and installation cost covered. For the record, the customer service at Dinan have been top notch and i didnt have to argue with them even if i did not had the coils installed at an authorized dealership. Even if the part is at fault here, i would not hesitate to do business again with them considering the quality of their after sale service.

i should receive the new part somewhere in the middle of october.. i'll keep you updated.




There's also another issue that i want to bring up. On my initial post i did not mentioned that i also had the trust arm bushing replaced 6 month ago. i've been running the KMAC adjustable caster bushing for maybe 4000 miles without any issue. the steering response is simply amazing. my caster angle is set to +9 on both sides. However, after having the strut mount replaced, i was still hearing clunking noise when braking, releasing the brake at a green light and hitting bump at low speed. i got the car checked again by the dealership and the tech noticed lot of "clean" grease coming out of the bushing. since the bushing have been on the car for quite a while, its clearly not related to installation. I'm wondering if the KMAC bushing may be at fault here (every other suspension component are in good shape, so its not a faulty ball joint or anything like that). I've sent an email to KMAC to have their input (still waiting for a reply)... Meanwhile i'll probably get the whole thrust arm replaced under warranty for a stock one for winter (i live in canada). If the clunking noise disappear after putting a new thrust arm, i'll probably look for another option like VAC or any other recommandation you might have...

[Stlblues]

Thanks for the update. The situations you describe where you hear the noise are similar to mine but mine sound like a combination of a rubbery groaning sound and clunking at low speeds and over bumps, like rolling up to a stop. Strangely, mine is much worse in the morning. After driving the car a while and later in the day I don't hear anything. I am wondering if mine is related to the bumpstops as the installer said they had to make the hole a little bigger to fit them on the shaft which makes me wonder if they are moving around on the strut

[FaRKle!]

Originally Posted by Estblue340

There's also another issue that i want to bring up. On my initial post i did not mentioned that i also had the trust arm bushing replaced 6 month ago. i've been running the KMAC adjustable caster bushing for maybe 4000 miles without any issue. the steering response is simply amazing. my caster angle is set to +9 on both sides. However, after having the strut mount replaced, i was still hearing clunking noise when braking, releasing the brake at a green light and hitting bump at low speed. i got the car checked again by the dealership and the tech noticed lot of "clean" grease coming out of the bushing. since the bushing have been on the car for quite a while, its clearly not related to installation. I'm wondering if the KMAC bushing may be at fault here (every other suspension component are in good shape, so its not a faulty ball joint or anything like that). I've sent an email to KMAC to have their input (still waiting for a reply)... Meanwhile i'll probably get the whole thrust arm replaced under warranty for a stock one for winter (i live in canada). If the clunking noise disappear after putting a new thrust arm, i'll probably look for another option like VAC or any other recommandation you might have...

Glad to hear you're being taken care of for the top mounts and springs!

9deg of caster is quite a bit! I've only run up to 8.5deg, and backed down to 8deg because I found I could cause some rubbing on high suspension compression.

The KMAC caster monoballs are potted/fully sealed, that's why you see the orange sealant instead of the actual monoball underneath. I'm pretty sure KMAC puts that grey grease on the monoball assembly underneath before putting on the orange sealent. Some of it coming out of the seam is pretty normal and I wouldn't worry about that.

For your clunking noise I'd first check the bolt torque holding the tension strut to the subframe. I've had one of those bolts work itself slightly loose after a shop didn't tighten it all the way. The noise it was most noticeable when braking, or when just starting to accelerate from a stop. The next thing you can check are the ball joints connecting the control arms to the knuckle.

[Estblue340]

Originally Posted by FaRKle!

Glad to hear you're being taken care of for the top mounts and springs!

9deg of caster is quite a bit! I've only run up to 8.5deg, and backed down to 8deg because I found I could cause some rubbing on high suspension compression.

The KMAC caster monoballs are potted/fully sealed, that's why you see the orange sealant instead of the actual monoball underneath. I'm pretty sure KMAC puts that grey grease on the monoball assembly underneath before putting on the orange sealent. Some of it coming out of the seam is pretty normal and I wouldn't worry about that.

For your clunking noise I'd first check the bolt torque holding the tension strut to the subframe. I've had one of those bolts work itself slightly loose after a shop didn't tighten it all the way. The noise it was most noticeable when braking, or when just starting to accelerate from a stop. The next thing you can check are the ball joints connecting the control arms to the knuckle.

I've never noticed any rubbing on hard cornering. Other than that, is there any downside on having high positive angle? The steering feel really heavy, but the car is really stable at high speed and on hard braking which is a plus for me.

I've check your video on tension strut replacement (well done btw).

you're saying that BMW recommend to replace the tension bolt before putting back the tension arm on the subframe. Could it be the reason why the bolt would loosen up ? could i put some locktight instead of putting a new bolt to prevent further loosening up ?

[Estblue340]

Originally Posted by Stlblues

Thanks for the update. The situations you describe where you hear the noise are similar to mine but mine sound like a combination of a rubbery groaning sound and clunking at low speeds and over bumps, like rolling up to a stop. Strangely, mine is much worse in the morning. After driving the car a while and later in the day I don't hear anything. I am wondering if mine is related to the bumpstops as the installer said they had to make the hole a little bigger to fit them on the shaft which makes me wonder if they are moving around on the strut

Do you have the dinan bumpstop kit or do you still have the stock ones ? Personnaly i went with the F80 bumpstop cause they were a much cheaper alternative and i havent heard of any fitment issue ...

[Stlblues]

Originally Posted by Estblue340

Do you have the dinan bumpstop kit or do you still have the stock ones ? Personnaly i went with the F80 bumpstop cause they were a much cheaper alternative and i havent heard of any fitment issue ...

Yes I have the Dinan bumpstops. I have not heard of any fitment issues either which is part of what makes me question if whatever the installer did with them is the source of my noise

[FaRKle!]

Originally Posted by Estblue340

I've never noticed any rubbing on hard cornering. Other than that, is there any downside on having high positive angle? The steering feel really heavy, but the car is really stable at high speed and on hard braking which is a plus for me.

I've check your video on tension strut replacement (well done btw).

you're saying that BMW recommend to replace the tension bolt before putting back the tension arm on the subframe. Could it be the reason why the bolt would loosen up ? could i put some locktight instead of putting a new bolt to prevent further loosening up ?

Aside from rubbing, I don't think there's much downside to having high caster angle. That said I would check where the arm/monoball is sitting relative to the subframe surrounding it with that much angle. I had a shop one time that adjusted the monoball such that the bolt was more towards the bottom and the main mass of the monoball/arm was on top, and that allowed the arm to contact the subframe on some bumps making a terrible noise. So, make sure there's enough room for deflection of that assembly, because it does move a bit.

BMW recommends replacing the bolt because it's a torque to yield bolt, so they set it to fastening torque, and then stretch the bolt. In my experience if you properly set it to fastening torque (or just a bit higher), things are OK, but anything a bit under fastening torque, and I've seen them loosen. I've never had one of those bolts loosen after I personally torqued it, but have had it loosen a couple times after other shops did it...

[Estblue340]

Originally Posted by FaRKle!

BMW recommends replacing the bolt because it's a torque to yield bolt, so they set it to fastening torque, and then stretch the bolt. In my experience if you properly set it to fastening torque (or just a bit higher), things are OK, but anything a bit under fastening torque, and I've seen them loosen. I've never had one of those bolts loosen after I personally torqued it, but have had it loosen a couple times after other shops did it...

It seem you are right on this one. i've checked myself and there was a small (but loud) play between the thrust arm and the subframe.

I could easily reproduce the noise just by putting pressure on the arm with my hand.

So i set back the bolt to 100nm + roughly 90 degree and the play was gone.

I drove for 30 miles and could not reproduce the noise. The bolt might have been loosen and tighten back like 3 times total, maybe i should just replace them with new ones to prevent further loosing ?

As for the bushing swelling grease, KMAC confirmed that [Bushes are pre lubed, so long term maintenance free. Having internal storage grooves for the silicone grease, so yes grease can be seen]

They also pointed me to the loosen bolt causing noise with the subframe.

I'll drive for a couple of day to see if the noise come back, but at this point im pretty confident we found the real issue here..



As for the strut mount .. i'm still wondering if the springs really caused the prematured failure on both sides .. will post pictures of the revised part to see if there is any real change in design on the new part ..

[FaRKle!]

Originally Posted by Estblue340

It seem you are right on this one. i've checked myself and there was a small (but loud) play between the thrust arm and the subframe.

I could easily reproduce the noise just by putting pressure on the arm with my hand.

So i set back the bolt to 100nm + roughly 90 degree and the play was gone.

Did you stretch the original bolt an additional 90deg, or did you get a new bolt and then stretch 90deg? I would probably replace the bolt if you took the original one and stretched another 90deg, because now it's "double stretched" and not designed for that.

[Estblue340]

Originally Posted by FaRKle!

Did you stretch the original bolt an additional 90deg, or did you get a new bolt and then stretch 90deg? I would probably replace the bolt if you took the original one and stretched another 90deg, because now it's "double stretched" and not designed for that.

Actually i loosen the bolt almost complety before retorquing it to 100nm + 90 degree to avoid over stretching it. Nevertheless its probably better at this point to put new ones to avoid any future issue ...

[FaRKle!]

Originally Posted by Estblue340

Actually i loosen the bolt almost complety before retorquing it to 100nm + 90 degree to avoid over stretching it. Nevertheless its probably better at this point to put new ones to avoid any future issue ...

Once a bolt has been stretched to yield, it doesn't constrict back. The 90deg past fastening torque causes a permanent stretch, so even if you loosen the bolt before retorquing and stretching, it's stretching the bolt twice.

Once setting the caster once, it really doesn't change even when aligning the other settings. You shouldn't need to get a new bolt every time you do an alignment since the setting shouldn't change and thus the bolt shouldn't have to be undone.