Loosen "plastic part" in rear suspension? Can i use 3M tape to put it back?

matthewheung · 02-22-2020, 04:34 PM

Today I find out both of my rear wheel shocks got this part loose. (Photo attached).I try to use my bare hands to pry it up back to the strut mounts but it still falling down. It seems there are no clips or some kinds of things to hold this "spongy" thing back to the mount? Can I just use some 3M tape or glue to make sure it stabilized inside the strut mount?

I really need your advice now since its winter in Canada and those salt would eat the shocks I believe.

2014 BMW 328Xi

Thank you all.

FaRKle! · 02-22-2020, 06:05 PM

That's your bump stop. Not an issue if it's not captured by the top mount, but feel free to shim the outer edge of it with duct tape or something so it sticks in there better.

jh_f30 · 02-24-2020, 09:44 AM

It sort of seems like the rubber has oxidized and shrunk, making it loose. Replacement bumpstops are relatively inexpensive but it would be a pain to take apart your rear shock assembly just to replace them. Not difficult at all, but a decent amount of work just for the bumpstops, however, that'd be my recommendation. I think the official name that BMW calls them are guard tube rear auxiliary dampers.

As FaRKle! suggested, some sort of adhesive strip applied around the top of the rubber to increase the radius enough to re-seat the friction fit into the upper shock mount should do the trick. Try to clean it out beforehand if you can. You probably don't want a bunch of salt and dirt permanently wedged in there.

DriveS · 02-24-2020, 01:00 PM

My guess is its contracted in the cold and lost the grip in the top plate. Have you tried pushing it back up and twisting at the same time to see if it stays in place?
If not, I would put a bit of silicone sealant on, push it in place and leave to dry

brigade24 · 02-24-2020, 02:04 PM

the bumpstops just stop the shocks/spring from bottoming out causing damage. As long as it stays on the shock, its fine.

i had saggy bump stops too! i fixed it with implants.

matthewheung · 02-27-2020, 08:12 PM

Thank you all for replying to me. I already put some sealant around the top of the bump stop and it works perfectly fine!

02-22-2020, 04:34 PM	#1
matthewheung New Member 2 Rep 10 Posts Drives: 2021 G20 325i Join Date: Sep 2019 Location: Toronto iTrader: (0)	Loosen "plastic part" in rear suspension? Can i use 3M tape to put it back? Today I find out both of my rear wheel shocks got this part loose. (Photo attached).I try to use my bare hands to pry it up back to the strut mounts but it still falling down. It seems there are no clips or some kinds of things to hold this "spongy" thing back to the mount? Can I just use some 3M tape or glue to make sure it stabilized inside the strut mount? I really need your advice now since its winter in Canada and those salt would eat the shocks I believe. 2014 BMW 328Xi Thank you all. Attached Images
	Appreciate 0 Tweet Quote

02-22-2020, 06:05 PM	#2
FaRKle! Brigadier General 4007 Rep 3,535 Posts Drives: 328d Wagon, M2 Comp, i4 eD35 Join Date: Sep 2016 Location: Bay Area, CA iTrader: (4) Garage List 2023 BMW i4 eDrive 35 [0.00] 2017 BMW 328dx Wagon [0.00] 2021 BMW M2 Competi ... [0.00]	That's your bump stop. Not an issue if it's not captured by the top mount, but feel free to shim the outer edge of it with duct tape or something so it sticks in there better. __________________ -328d Wagon Build Log (with helpful reference links) -My YouTube Channel for some of the best DIYs and in depth information Please don't PM me for suspension recommendations unless interested in paid private consultations.
	Appreciate 0 Quote

02-24-2020, 09:44 AM	#3
jh_f30 Lieutenant Colonel 1306 Rep 1,827 Posts Drives: 2013 335i Sportline Auto RWD Join Date: Aug 2017 Location: Bay Area, CA iTrader: (2)	It sort of seems like the rubber has oxidized and shrunk, making it loose. Replacement bumpstops are relatively inexpensive but it would be a pain to take apart your rear shock assembly just to replace them. Not difficult at all, but a decent amount of work just for the bumpstops, however, that'd be my recommendation. I think the official name that BMW calls them are guard tube rear auxiliary dampers. As FaRKle! suggested, some sort of adhesive strip applied around the top of the rubber to increase the radius enough to re-seat the friction fit into the upper shock mount should do the trick. Try to clean it out beforehand if you can. You probably don't want a bunch of salt and dirt permanently wedged in there. __________________ 2013 F30 335i RWD ZF Melbourne Red ~Remus Sport Axleback~VRSF Chargepipe~VRSF Catless Downpipe~GPlus FMIC~HR Sport Springs~Active Autowerke OBD Flash Tune Stage 2~
	Appreciate 0 Quote

02-24-2020, 01:00 PM	#4
DriveS Lieutenant 220 Rep 541 Posts Drives: F30 335d Join Date: Dec 2011 Location: Newcastle iTrader: (0)	My guess is its contracted in the cold and lost the grip in the top plate. Have you tried pushing it back up and twisting at the same time to see if it stays in place? If not, I would put a bit of silicone sealant on, push it in place and leave to dry
	Appreciate 0 Quote

02-24-2020, 02:04 PM	#5
brigade24 First Lieutenant 156 Rep 320 Posts Drives: 2013 335 X-dive Join Date: Jun 2018 Location: Canada iTrader: (0)	the bumpstops just stop the shocks/spring from bottoming out causing damage. As long as it stays on the shock, its fine. i had saggy bump stops too! i fixed it with implants.
	Appreciate 1 johnung4525.00 Quote

02-27-2020, 08:12 PM	#6
matthewheung New Member 2 Rep 10 Posts Drives: 2021 G20 325i Join Date: Sep 2019 Location: Toronto iTrader: (0)	Thank you all for replying to me. I already put some sealant around the top of the bump stop and it works perfectly fine!
	Appreciate 0 Quote