Rear Shock Question

Randy Johnson · 10-16-2021, 04:53 PM

I noticed on my 435i that the rear shock bump stops have disintegrated. The bump stop is so far gone it no longer holds the plastic cover over the shock shaft. I was checking to see how hard removing the shocks are to replace the bump stops and noticed the shocks do not go back up when compressed. Is this normal on bmw? I've change a few suspensions in my time and the shock always would expand once compressed. Not sure if I should also replace the shocks. I have 61k miles. Car rides fine with no bounce.

Orion4 · 10-16-2021, 06:54 PM

61K miles on your suspension is in the range of starting to wear out. Depends on driving style and roads. The shocks not rebounding is a clear sign of failing/failed shocks. If your rears are going, there's a good bet the front struts are dead, too. I recently replaced my front struts and rear shocks with Bilstein B-4s from FCP Eur at 165K, but they were totally dead. Retains original ride height.

Randy Johnson · 10-16-2021, 08:09 PM

Never had shock go bad so fast. Not sure if these are gas filled which would rebound faster than non gas. Shocks should not alter ride height unless the wrong ones where installed.

Orion4 · 10-17-2021, 10:50 AM

There are a number of shocks that will change ride height for the model. matching with the correct springs is required. As an example, Bilstein makes several.

Orion4 · 10-17-2021, 04:35 PM

BTW: all the BMW Struts/Shocks and related aftermarket are gas. Which are really a hybrid Hydraulic/gas (usually N2) for more responsive performance. The OEM struts/shocks on my 13 3335i were Sach. I think only vintage/classics cars may still use pure hydraulic for softer/smoother ride.

johnung · 10-17-2021, 09:23 PM

Quote:

Originally Posted by Randy Johnson

I noticed on my 435i that the rear shock bump stops have disintegrated. The bump stop is so far gone it no longer holds the plastic cover over the shock shaft. I was checking to see how hard removing the shocks are to replace the bump stops and noticed the shocks do not go back up when compressed. Is this normal on bmw? I've change a few suspensions in my time and the shock always would expand once compressed. Not sure if I should also replace the shocks. I have 61k miles. Car rides fine with no bounce.

The original shocks are really crap so not surprising at your mileage. IMO replace them with Koni Special Actives. Huge difference for a daily driver in comfort and sportiness

cfm56d7b · 10-18-2021, 11:06 AM

OP, is the shock in question M Adaptive or regular?

10-16-2021, 04:53 PM	#1
Randy Johnson M340i 393 Rep 968 Posts Drives: BMW M340i Join Date: Sep 2019 Location: South FLA iTrader: (1) Garage List 2021 BMW M340i [10.00]	Rear Shock Question I noticed on my 435i that the rear shock bump stops have disintegrated. The bump stop is so far gone it no longer holds the plastic cover over the shock shaft. I was checking to see how hard removing the shocks are to replace the bump stops and noticed the shocks do not go back up when compressed. Is this normal on bmw? I've change a few suspensions in my time and the shock always would expand once compressed. Not sure if I should also replace the shocks. I have 61k miles. Car rides fine with no bounce.
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10-16-2021, 06:54 PM	#2
Orion4 Lieutenant Colonel 481 Rep 1,572 Posts Drives: 2013 335i Sport Line Sedan Join Date: Aug 2009 Location: Melbourne, FL iTrader: (0)	61K miles on your suspension is in the range of starting to wear out. Depends on driving style and roads. The shocks not rebounding is a clear sign of failing/failed shocks. If your rears are going, there's a good bet the front struts are dead, too. I recently replaced my front struts and rear shocks with Bilstein B-4s from FCP Eur at 165K, but they were totally dead. Retains original ride height.
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10-16-2021, 08:09 PM	#3
Randy Johnson M340i 393 Rep 968 Posts Drives: BMW M340i Join Date: Sep 2019 Location: South FLA iTrader: (1) Garage List 2021 BMW M340i [10.00]	Never had shock go bad so fast. Not sure if these are gas filled which would rebound faster than non gas. Shocks should not alter ride height unless the wrong ones where installed.
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10-17-2021, 10:50 AM	#4
Orion4 Lieutenant Colonel 481 Rep 1,572 Posts Drives: 2013 335i Sport Line Sedan Join Date: Aug 2009 Location: Melbourne, FL iTrader: (0)	There are a number of shocks that will change ride height for the model. matching with the correct springs is required. As an example, Bilstein makes several.
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10-17-2021, 04:35 PM	#5
Orion4 Lieutenant Colonel 481 Rep 1,572 Posts Drives: 2013 335i Sport Line Sedan Join Date: Aug 2009 Location: Melbourne, FL iTrader: (0)	BTW: all the BMW Struts/Shocks and related aftermarket are gas. Which are really a hybrid Hydraulic/gas (usually N2) for more responsive performance. The OEM struts/shocks on my 13 3335i were Sach. I think only vintage/classics cars may still use pure hydraulic for softer/smoother ride.
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10-18-2021, 11:06 AM	#7
cfm56d7b Lieutenant General 5886 Rep 10,256 Posts Drives: 2017 440i Gran Coupe & 2015 X5 Join Date: Nov 2012 Location: Orange County, CA iTrader: (2)	OP, is the shock in question M Adaptive or regular?
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