[CarlosM4]

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Hi I have been travelling with our G30 540i, I had a look under the car (the car has no suspension noise), but I noticed some weird thing close to the thrust arm bushing. It is not leaking or anything but I found this weird.

It seems very weird, as if a piece of the bushing had an issue. The car has 24k miles. No potholes just dealing with the shitty roads here. I have a F90 M5, but the thrust arm in it is different to compare.

I cant take it to the dealer or Indy as of right now as I am away from home.

[CarlosM4]

Forgot to mention that its looking like that apparently for over a month.

[nonford]

@ 24k, I'm surprised at what seems to be a crack in the first pic. However, BMW bushings suck! As, in they don't last long, but 24k is kind of short, but not overwhelming surprised. In stead of new arms, I'd press them out and replace them, not hard at all. I've done these numerous of times and not really surprised how often these go. But heh, its a BMW right?

[CarlosM4]

Originally Posted by nonford

@ 24k, I'm surprised at what seems to be a crack in the first pic. However, BMW bushings suck! As, in they don't last long, but 24k is kind of short, but not overwhelming surprised. In stead of new arms, I'd press them out and replace them, not hard at all. I've done these numerous of times and not really surprised how often these go. But heh, its a BMW right?

I sent this picture to others, and yeah, apparently its a small crack (you mean the black "scratch" on the right side). I was told this is fine for this type of hydraulic bushing on the G30, and it does not cause noise or affect the car's handling and dampening. Nonetheless I found it very weird as well, as there was not pothole to "cause" that, and at 24k miles it should be brand new.

[aerof16]

Thrust arm bushings on 540i are not hydraulically filled like on the M550. They’re just solid rubber.

Only way to tell if it’s bad is to stick a pry bar in there and see if there is excessive movement/wear on it.

[CarlosM4]

Originally Posted by aerof16

Thrust arm bushings on 540i are not hydraulically filled like on the M550. They’re just solid rubber.

Only way to tell if it’s bad is to stick a pry bar in there and see if there is excessive movement/wear on it.

Its hydraulic filled as well. I cam attest to that.

[aerof16]

Originally Posted by CarlosM4

Its hydraulic filled as well. I cam attest to that.

What year is your car? My 2017 definitely is not hydraulically filled - I’ve changed them because I was chasing a noise I thought might have been them and was surprised to find out that it was just solid rubber. Maybe that changed at some point.

Either way, if it is filled and it’s not leaking, it’s fine. Nothing “looks” wrong with the bushing in the pictures.

[CarlosM4]

Originally Posted by aerof16

What year is your car? My 2017 definitely is not hydraulically filled - I’ve changed them because I was chasing a noise I thought might have been them and was surprised to find out that it was just solid rubber. Maybe that changed at some point.

Either way, if it is filled and it’s not leaking, it’s fine. Nothing “looks” wrong with the bushing in the pictures.

Really? Was yours on OEM bushings?

From the spec sheet of the Lemforder (OEM manufacturer) the information is that the bushings are hydraulic, but its also full of inaccuracies. I have had issues with hydraulic bushings on my X3 M40i, I owned before so I was 110% sure the 540i (a more sophisticated with a more elaborate suspension) would have a hydraulic bushing.

This is a 2018/19 540i. If its a solid bushing its also in good conditions right?

[aerof16]

Originally Posted by CarlosM4

Really? Was yours on OEM bushings?

From the spec sheet of the Lemforder (OEM manufacturer) the information is that the bushings are hydraulic, but its also full of inaccuracies. I have had issues with hydraulic bushings on my X3 M40i, I owned before so I was 110% sure the 540i (a more sophisticated with a more elaborate suspension) would have a hydraulic bushing.

This is a 2018/19 540i. If its a solid bushing its also in good conditions right?

Yes mine were OEM and I replaced them with OEM. Mine were solid rubber and some research indicated that hydraulic filled was standard on the M550 but the 540 didn’t get them.

Yours look fine to me but you cannot really say without checking for excessive movement. My guess is the solid rubber are way more reliable than the hydro filled, mine looked really good at like 90k miles when I swapped them out - thought maybe the ball joint had gone bad on one but turns out it was fine.

[CarlosM4]

Originally Posted by aerof16

Yes mine were OEM and I replaced them with OEM. Mine were solid rubber and some research indicated that hydraulic filled was standard on the M550 but the 540 didn’t get them.

Yours look fine to me but you cannot really say without checking for excessive movement. My guess is the solid rubber are way more reliable than the hydro filled, mine looked really good at like 90k miles when I swapped them out - thought maybe the ball joint had gone bad on one but turns out it was fine.

Its funny, there is contradicting info regarding if the bushing is hydraulic or solid rubber. As I was checking out the Thrust Arm bushing for the G30 540i and 530i is a different part number to that of the G30 M550i although the arm is the same. The only difference is in the rubber bushing mounts. But if you look at Lemforders website, it says the bushing is Hydraulic filled. I looked at Febi/Bilstein and Stierbar replacement parts, and it says the bushings are not Hydraulic filled and are to OEM specs. If you look at the bushing as a stand alone (Lemforder does not sell it anymore), all are solid rubber bushings and funnily enough, the G30s rubber bushing is the same part as the F10 M5, which is a solid rubber one.

Tough one to crack. I think you are right though, looking at the bushing it does not appear to be Hydraulic filled, although I find that to be odd, given the complexity of the G30 suspension.

It also appears more recently BMW gave up on the hydraulic bushing as other G platform BMWs do not appear to have it.

[Thecastle]

Everyone I've ever replaced was hydraulic filled, and I've personally done it many times on different vehicles, X5's, F10, G30's etc. Of course some may not be so ymmv

I would not replace the bushing the cost savings is so minimal as compared to replacing the whole arm. In addition you need access to a hydraulic press and the ball joints do wear out. So replace them all for the extra $30, and the job is easier, get new ball joints, and you don't need a press.

Pro-TIP if you diy the arm. Do not back the nuts off completely on the ball joints to keep the shaft from mushrooming. Ball joint spreaders aren't worth the money. Use at least a 5 lbs sledge hammer and hit the nut. It pops out, the other thing is have some good torque wrenchs they these bolts are like 200ft/lbs.

[CarlosM4]

Originally Posted by Thecastle

Everyone I've ever replaced was hydraulic filled, and I've personally done it many times on different vehicles, X5's, F10, G30's etc. Of course some may not be so ymmv

I would not replace the bushing the cost savings is so minimal as compared to replacing the whole arm. In addition you need access to a hydraulic press and the ball joints do wear out. So replace them all for the extra $30, and the job is easier, get new ball joints, and you don't need a press.

Pro-TIP if you diy the arm. Do not back the nuts off completely on the ball joints to keep the shaft from mushrooming. Ball joint spreaders aren't worth the money. Use at least a 5 lbs sledge hammer and hit the nut. It pops out, the other thing is have some good torque wrenchs they these bolts are like 200ft/lbs.

The bushings in my G30 are alright actually. As can be seen from the picture, they are fine. Its a solid bushing, aerof16 is right. I confirmed it with my SA.

Apparently only the 50i cars get Hydraulic Bushings in the G platform. All the rest is solid bushings. Learning something new everyday.

And the G cars solid bushings are made of the same material as the M cars as well. So funnily enough the replacement for only the bushing in the G30, is the same as the F10 M5.

[CarlosM4]

Just as a general info, to keep stored here for the forum:

F cars - Thrust Arms are Hydraulic Bushings
G cars - Thrust Arms are Solid Rubber Bushings (exceptions G30 M550i, X5s, X7s, 7s), all the other G01s, G20s, G30s are all Solid Rubber Bushings, including M cars

[ashokgadeking]

Interesting, my M340i had hydraulic bushings that I had to replace when they started leaking at around 55k.

[CarlosM4]

Originally Posted by ashokgadeking

Interesting, my M340i had hydraulic bushings that I had to replace when they started leaking at around 55k.

The Thrust Arm for the G20 M340i sold here (in the dealer - OEM) is Solid Rubber Bushing. So there could be variations depending on where you are located as well. The G20 M340is sold in the U.S., are built in the US right?

[lnxguy]

G30 530/540's absolutely have liquid filled tension struts from the factory.

[CarlosM4]

Originally Posted by lnxguy

G30 530/540's absolutely have liquid filled tension struts from the factory.

I thought the same thing, but they don't. Only the G30 M550i has.

In fact BMW has changed their bushing setup in the G platform car. It caught me off guard too.

[CarlosM4]

If your thrust arm is: 31106861158 - its Hydraulic Bushing - the same Thrust Arm used in the M760Li, 750Li/i, 740Li/i. - M550i as well

If your thrust arm is: 31106861161 - its Solid Rubber Bushing.

[CarlosM4]

For the G20:
If your thrust arm is 31106879850 - its Hydraulic filled

If your thrust arm is 31106894661 - its Solid Rubber Bushing

Apparently some G20 M340i have Hydraulic filled bushings, and some don't - from what I saw they appear to have switched in the LCI, but I can not confirm info on the G20. The G30 I have confirmed with my S.A., in fact like I said the info he gave me was this:

The replacement parts available in the dealer here:

F cars - Thrust Arms are Hydraulic Bushings
G cars - Thrust Arms are Solid Rubber Bushings (exceptions G30 M550i, X5s, X7s, 7s), all the other G01s, G20s, G30s are all Solid Rubber Bushings, including M cars

[ashokgadeking]

Mine was a 2020 M340i.

[CarlosM4]

Originally Posted by ashokgadeking

Mine was a 2020 M340i.

Yeah this is a Hydraulic Bushing, Control Arm - 31106879850

The bushings are very different. The same thing for the G30s too.

I never thought BMW had stopped using Hydraulic Bushings, but apparently they have.

[lnxguy]

Originally Posted by CarlosM4

I thought the same thing, but they don't. Only the G30 M550i has.

In fact BMW has changed their bushing setup in the G platform car. It caught me off guard too.

That's crazy. I guess I'll see when I gotta swap mine in the near future lol.