Need some help with Bilstein B4 please...

Bimmer_Engineer · 03-21-2021, 07:25 PM

I’ve got a 11/2006 build e90 335 with the sports suspension (option 226). I bought some bilstein b4s from rock auto that are part number 19303581, per ecstuning this should be a direct replacement for my stock shocks. I had trouble getting the upper mount reinstalled, the nut won’t thread down far enough to expose the 6 mm backup. So I took the shock out and compared with the one I took off and the thread on the top of the shocks is totally different. The bilstein is coarser and the nut on the mount won’t tighten without cross threading. I checked with the stock shock and the nuts for the new mount thread on fine. Pic comparing the mount threads is below for comparison.

So I’m at a little bit of a loss here as to what the issue is, I have 3 different upper shock mounts and none of them match the top thread on this bilstein. Is there a different mount I need to get?

relative4 · 03-21-2021, 08:52 PM

Did the Bilstein shocks not come with new nuts?

Bimmer_Engineer · 03-21-2021, 08:56 PM

Quote:

Originally Posted by relative4

Did the Bilstein shocks not come with new nuts?

On the bottom but not the top...

328iFitz · 03-21-2021, 08:59 PM

Quote:

Originally Posted by Bimmer_Engineer

Quote:

Originally Posted by relative4

Did the Bilstein shocks not come with new nuts?

On the bottom but not the top...

When I did mine (704a used a 19-135052 PN) I had reused my oem upper mounts temporarily cause my new ones hadn't arrived in time and they went right on. I know it is a different part number and unit all together but that is weird.

Bimmer_Engineer · 03-22-2021, 08:30 AM

Quote:

Originally Posted by 328iFitz

When I did mine (704a used a 19-135052 PN) I had reused my oem upper mounts temporarily cause my new ones hadn't arrived in time and they went right on. I know it is a different part number and unit all together but that is weird.

Lol...idk where I got the shock that I have but the PN listed on rock auto today is 19135952...

relative4 · 03-22-2021, 10:10 AM

What are the thread pitches?

328iFitz · 03-22-2021, 11:48 AM

Quote:

Originally Posted by Bimmer_Engineer

Quote:

Originally Posted by 328iFitz

When I did mine (704a used a 19-135052 PN) I had reused my oem upper mounts temporarily cause my new ones hadn't arrived in time and they went right on. I know it is a different part number and unit all together but that is weird.

Lol...idk where I got the shock that I have but the PN listed on rock auto today is 19135952...

Yeah man, haha idk mine worked with the oem top
nut and of course the new Monroe top nut/mount I got as well.

bluewater328 · 03-22-2021, 04:51 PM

Quote:

Originally Posted by 328iFitz

Yeah man, haha idk mine worked with the oem top
nut and of course the new Monroe top nut/mount I got as well.

Yeah, rear upper shock mount was reusable as well as Dinan's and the Autozone/Monroe specials. I think you might just have the wrong part; pitch looks off.

https://www.fcpeuro.com/products/bmw...er-33506771737

Bimmer_Engineer · 03-22-2021, 07:38 PM

Quote:

Originally Posted by bluewater328

Yeah, rear upper shock mount was reusable as well as Dinan's and the Autozone/Monroe specials. I think you might just have the wrong part; pitch looks off.

https://www.fcpeuro.com/products/bmw...er-33506771737

Yeah I figured that out now...rock auto had the fronts and rears for about $100 less than ecs so I went with that. They had this part listed for 2007 335 with sports suspension. Today they had a different part listed so idk...

I’m returning the coarse thread ones and I ordered a new set...

bluewater328 · 03-23-2021, 05:19 AM

Quote:

Originally Posted by Bimmer_Engineer

Quote:

Originally Posted by bluewater328

Yeah, rear upper shock mount was reusable as well as Dinan's and the Autozone/Monroe specials. I think you might just have the wrong part; pitch looks off.

https://www.fcpeuro.com/products/bmw...er-33506771737

Yeah I figured that out now...rock auto had the fronts and rears for about $100 less than ecs so I went with that. They had this part listed for 2007 335 with sports suspension. Today they had a different part listed so idk...

I’m returning the coarse thread ones and I ordered a new set...

Bummer, hope that all gets sorted. At least you have your answer/solution at hand.

The Nightman · 03-23-2021, 12:47 PM

I wonder if it's a manufacturing defect? For whatever it's worth, I installed Bilstein B4 shocks #19-135052 on my E90 with sport springs and the top threads were correct.

Bimmer_Engineer · 03-23-2021, 02:43 PM

Quote:

Originally Posted by freedomfries

I wonder if it's a manufacturing defect? For whatever it's worth, I installed Bilstein B4 shocks #19-135052 on my E90 with sport springs and the top threads were correct.

Thanks I've got those on order now. The other ones are going back to Rock Auto today. I don't know where the disconnect was but RockAuto clearly said the 19303581's were for a 2007 E90 w/sports suspension...

Anxious to get these new ones in. Car's been on jack stands for 10 days now...

lowrydr310 · 05-28-2021, 05:16 PM

Well count me in as another one with this problem. I bought the 19-303581 as they're listed as fitting the 2006 330i (Sedan) with Sport suspension. I even confirmed this on the Bilstein website which lists this as the 'correct' shock.

However I just received them and have this same issue. The threads on the top of the rod are too coarse and neither my original BMW shock mount nut nor my new replacement shock mount nut fit on those threads.

It looks like those 19-135052 shocks are hard to find, as none of the usual retailers have them in stock.

I have new B4 struts up front and was hoping to match the rears, but would I be OK installing Sachs on the rear? My original rear shocks are blown, bumpstops are gone and the rod doesn't extend when pushed in.

TGTIW · 09-24-2021, 10:03 AM

This just happened to me as well with the 19-303581
Either there's a part # mistake or a manufacturing mistake.

lowrydr310 · 09-24-2021, 11:49 AM

Quote:

Originally Posted by TGTIW

This just happened to me as well with the 19-303581
Either there's a part # mistake or a manufacturing mistake.

Where did you buy yours?

I suspect this was a manufacturing issue from Bilstein. A few months ago when I bought mine, FCP and all the other reputable euro-focused retailers didn't have them available. I'm guessing they were aware of it and halted the sales. I got mine from Tire Rack and they were the wrong threads, but they're good about returns.

FCP and the others have the 19-303581 back in stock, and I'm hoping that the problem has been corrected.

TGTIW · 09-24-2021, 06:14 PM

Mine came from ECS Tuning, they asked for photos so hopefully I'll get this sorted.

TGTIW · 10-02-2021, 05:21 PM

So this is the answer I received:
-We are still waiting on Bilstein. This has happened before where they made a bunch wrong. I would recommend to exchange for a different brand.-

I'm less concerned about the vague answer than I am about the quality control at Bilstein.

mifesto · 10-07-2021, 10:05 AM

i just got rear b6 (not b4) but had no problems. tried fitting oem or monroe, both thread in fine.

lowrydr310 · 10-08-2021, 02:32 PM

Quote:

Originally Posted by TGTIW

So this is the answer I received:
-We are still waiting on Bilstein. This has happened before where they made a bunch wrong. I would recommend to exchange for a different brand.-

I'm less concerned about the vague answer than I am about the quality control at Bilstein.

That's what I ended up doing. I couldn't confirm the correct B4 part with any other retailer and wanted to get new shocks for an upcoming alignment appointment, so I have Sachs shocks in the rear and Bilstein B4 struts up front.

I'm thinking of scrapping it all and just going with the B12 kit.

npwanabe · 02-06-2022, 10:11 PM

Just bought 2 bilstein 19-303581' s from RMeuropean for my '08 335i. One shock had the correct thread pitch. The other didnt. To the best of my reckoning the correct spec is M10 -1.0. It looks like Bilstein made a batch that the upper spindle has M10-1.25.

03-21-2021, 07:25 PM	#1
Bimmer_Engineer Lieutenant Colonel 1044 Rep 1,667 Posts Drives: 2007 335i Join Date: May 2018 Location: Louisiana iTrader: (0) Garage List 2008 Porsche Boxster [0.00] 2016 Mercedes Benz ... [0.00] 2007 BMW 335i [9.50]	Need some help with Bilstein B4 please... I’ve got a 11/2006 build e90 335 with the sports suspension (option 226). I bought some bilstein b4s from rock auto that are part number 19303581, per ecstuning this should be a direct replacement for my stock shocks. I had trouble getting the upper mount reinstalled, the nut won’t thread down far enough to expose the 6 mm backup. So I took the shock out and compared with the one I took off and the thread on the top of the shocks is totally different. The bilstein is coarser and the nut on the mount won’t tighten without cross threading. I checked with the stock shock and the nuts for the new mount thread on fine. Pic comparing the mount threads is below for comparison. So I’m at a little bit of a loss here as to what the issue is, I have 3 different upper shock mounts and none of them match the top thread on this bilstein. Is there a different mount I need to get? Attached Images
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03-21-2021, 08:52 PM	#2
relative4 Major 611 Rep 1,272 Posts Drives: '08 335xi E90 MT stage 1+ Join Date: Feb 2019 Location: Denver, CO iTrader: (0)	Did the Bilstein shocks not come with new nuts?
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03-22-2021, 10:10 AM	#6
relative4 Major 611 Rep 1,272 Posts Drives: '08 335xi E90 MT stage 1+ Join Date: Feb 2019 Location: Denver, CO iTrader: (0)	What are the thread pitches?
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03-23-2021, 12:47 PM	#11
The Nightman Cometh 1090 Rep 1,305 Posts Drives: Boy's Soul Join Date: Jul 2016 Location: Boy's Hole iTrader: (4) Garage List E90 LCI "330i& ... [10.00]	I wonder if it's a manufacturing defect? For whatever it's worth, I installed Bilstein B4 shocks #19-135052 on my E90 with sport springs and the top threads were correct.
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05-28-2021, 05:16 PM	#13
lowrydr310 Robot 1682 Rep 2,189 Posts Drives: 2006 330i, 2007 E93 335i Join Date: Apr 2013 Location: Souhtrne Califniora iTrader: (0)	Bilstein BS Well count me in as another one with this problem. I bought the 19-303581 as they're listed as fitting the 2006 330i (Sedan) with Sport suspension. I even confirmed this on the Bilstein website which lists this as the 'correct' shock. However I just received them and have this same issue. The threads on the top of the rod are too coarse and neither my original BMW shock mount nut nor my new replacement shock mount nut fit on those threads. It looks like those 19-135052 shocks are hard to find, as none of the usual retailers have them in stock. I have new B4 struts up front and was hoping to match the rears, but would I be OK installing Sachs on the rear? My original rear shocks are blown, bumpstops are gone and the rod doesn't extend when pushed in.
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09-24-2021, 10:03 AM	#14
TGTIW Second Lieutenant 130 Rep 245 Posts Drives: 2010 328i Join Date: May 2013 Location: Knoxville iTrader: (2)	This just happened to me as well with the 19-303581 Either there's a part # mistake or a manufacturing mistake.
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09-24-2021, 06:14 PM	#16
TGTIW Second Lieutenant 130 Rep 245 Posts Drives: 2010 328i Join Date: May 2013 Location: Knoxville iTrader: (2)	Mine came from ECS Tuning, they asked for photos so hopefully I'll get this sorted.
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10-02-2021, 05:21 PM	#17
TGTIW Second Lieutenant 130 Rep 245 Posts Drives: 2010 328i Join Date: May 2013 Location: Knoxville iTrader: (2)	So this is the answer I received: -We are still waiting on Bilstein. This has happened before where they made a bunch wrong. I would recommend to exchange for a different brand.- I'm less concerned about the vague answer than I am about the quality control at Bilstein.
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10-07-2021, 10:05 AM	#18
mifesto Private First Class 26 Rep 141 Posts Drives: 2008 335xi Join Date: Aug 2016 Location: nj iTrader: (1)	i just got rear b6 (not b4) but had no problems. tried fitting oem or monroe, both thread in fine.
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02-06-2022, 10:11 PM	#20
npwanabe New Member 2 Rep 5 Posts Drives: BMW 335i Join Date: Apr 2019 Location: Columbia, TN iTrader: (0)	correct spec vs "the bad batch" Just bought 2 bilstein 19-303581' s from RMeuropean for my '08 335i. One shock had the correct thread pitch. The other didnt. To the best of my reckoning the correct spec is M10 -1.0. It looks like Bilstein made a batch that the upper spindle has M10-1.25. Last edited by npwanabe; 02-07-2022 at 01:50 PM.. Reason: adding info
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