Urethane filling motor and transmission mounts

hardparker · 09-14-2020, 08:44 PM

In the quest for harder launches and transfer case output shaft longevity, I deconstructed my passenger motor mount and filled it with 3M Window Weld inside and out after gutting the fluid damper portions. The four ports on the top of the mount, drilled with a 1/4 drill bit, allow for easy filling of the top. Fill through each port in turn until it oozes out all of the ports to make sure it's filled. That's probably all that needs doing to stiffen it up nicely, filling the void inside between the shell and the bonded EPDM and rubber of the mount itself. A little fill in between the outer black portion of the mount around the stud should help, too.

I went the extra distance and removed the bottom layers, exposing the rubber mount and drilling a couple of holes for fill/vent ports to ensure good and thorough filling. After the tube was done for other purposes, I filled the bottom, because why not. I'd say this is probably overkill and it's definitely a pain in the ass.

After that, I filled the transmission mount, making sure to fill it to the rear of the mount to the point where it counts.

It'll take a while to cure and that's okay, because my big turbo build in still in progress.

hardparker · 09-22-2020, 08:47 PM

So far so good. Zero noticeable increase in vibration. Wife agrees. We'll see if it helps with launches or TC longevity.

bimmer ///man · 11-28-2020, 04:38 PM

Any updates? I’m replacing my motor mounts soon and may do this depending on your results.

longvvo · 11-28-2020, 10:24 PM

Awsome! I just did my motor mounts today

hardparker · 12-01-2020, 06:39 PM

Quote:

Originally Posted by bimmer ///man

Any updates? I’m replacing my motor mounts soon and may do this depending on your results.

No problems and isn't really any harsher than stock. It doesn't really feel any different, but I figure it'll help keep the driveline better aligned during really hard drag launches.

fullthrottle540 · 12-07-2020, 09:07 PM

Nice work. Looking at your signature, I have to check out your X3. Do you have a build thread? I have some questions for you.

6MT_Addict · 12-08-2020, 04:09 PM

Creative, but why not just replace with urethane mounts?

I don't think this will make a huge difference, seems like the adhesive injected in just fills the air cavity between the rubber insert (EPDM is a synthetic rubber) and metal housing. The majority of the mount is still aged rubber.

You'll probably see better results in stiffness from one of these:

https://store.034motorsport.com/moto...2-n54-n55.html

https://www.ecstuning.com/b-turner-m.../002445tms~dk/

hardparker · 12-08-2020, 09:10 PM

Quote:

Originally Posted by fullthrottle540

Nice work. Looking at your signature, I have to check out your X3. Do you have a build thread? I have some questions for you.

Nah, don't really have a comprehensive build thread for my car.

Quote:

Originally Posted by 6MT_Addict

Creative, but why not just replace with urethane mounts?

I don't think this will make a huge difference, seems like the adhesive injected in just fills the air cavity between the rubber insert (EPDM is a synthetic rubber) and metal housing. The majority of the mount is still aged rubber.

You'll probably see better results in stiffness from one of these:

https://store.034motorsport.com/moto...2-n54-n55.html

https://www.ecstuning.com/b-turner-m.../002445tms~dk/

Because nobody makes them for the F25. F25 mounts fit F25 and F26 and that's it.

HDBoss · 01-01-2021, 06:08 AM

Great job!

Here is mine - right side mount after 150k km... I just changed it to a new one.

09-14-2020, 08:44 PM	#1
hardparker Father of Frankenfold 299 Rep 531 Posts Drives: Yo daddy's 2014 X3 M Sport Join Date: Jan 2017 Location: Albuquerque iTrader: (2) Garage List 2013 BMW X1 [0.00] 2014 BMW X3 [0.00]	Urethane filling motor and transmission mounts In the quest for harder launches and transfer case output shaft longevity, I deconstructed my passenger motor mount and filled it with 3M Window Weld inside and out after gutting the fluid damper portions. The four ports on the top of the mount, drilled with a 1/4 drill bit, allow for easy filling of the top. Fill through each port in turn until it oozes out all of the ports to make sure it's filled. That's probably all that needs doing to stiffen it up nicely, filling the void inside between the shell and the bonded EPDM and rubber of the mount itself. A little fill in between the outer black portion of the mount around the stud should help, too. I went the extra distance and removed the bottom layers, exposing the rubber mount and drilling a couple of holes for fill/vent ports to ensure good and thorough filling. After the tube was done for other purposes, I filled the bottom, because why not. I'd say this is probably overkill and it's definitely a pain in the ass. After that, I filled the transmission mount, making sure to fill it to the rear of the mount to the point where it counts. It'll take a while to cure and that's okay, because my big turbo build in still in progress. Attached Images __________________ F25 X3 35i M Sport \| Frankenfold 6662 \| VRSF Race IC \| FTP CP \| BM3 tuned \| XDI-35 HPFP \| Stage 2 LPFP \| Ethanol mixed \| WMI \| Oil cooler \| xHP \| X5/550i brakes Last edited by hardparker; 09-14-2020 at 09:34 PM..
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09-22-2020, 08:47 PM	#2
hardparker Father of Frankenfold 299 Rep 531 Posts Drives: Yo daddy's 2014 X3 M Sport Join Date: Jan 2017 Location: Albuquerque iTrader: (2) Garage List 2013 BMW X1 [0.00] 2014 BMW X3 [0.00]	So far so good. Zero noticeable increase in vibration. Wife agrees. We'll see if it helps with launches or TC longevity. __________________ F25 X3 35i M Sport \| Frankenfold 6662 \| VRSF Race IC \| FTP CP \| BM3 tuned \| XDI-35 HPFP \| Stage 2 LPFP \| Ethanol mixed \| WMI \| Oil cooler \| xHP \| X5/550i brakes
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11-28-2020, 04:38 PM	#3
bimmer ///man Captain 100 Rep 691 Posts Drives: M Join Date: Mar 2009 Location: 805 iTrader: (0)	Any updates? I’m replacing my motor mounts soon and may do this depending on your results.
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11-28-2020, 10:24 PM	#4
longvvo New Member 14 Rep 9 Posts Drives: BMW X3 Join Date: Nov 2020 Location: Alabama iTrader: (0)	Awsome! I just did my motor mounts today
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12-07-2020, 09:07 PM	#6
fullthrottle540 Registered 0 Rep 3 Posts Drives: x3 Join Date: Dec 2020 Location: San Diego iTrader: (0)	Nice work. Looking at your signature, I have to check out your X3. Do you have a build thread? I have some questions for you.
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12-08-2020, 04:09 PM	#7
6MT_Addict Captain 283 Rep 888 Posts Drives: 08 135i M Sport 6MT, 15 X3 35i Join Date: Feb 2013 Location: Edmonton iTrader: (2) Garage List 2008 BMW 135i [10.00]	Creative, but why not just replace with urethane mounts? I don't think this will make a huge difference, seems like the adhesive injected in just fills the air cavity between the rubber insert (EPDM is a synthetic rubber) and metal housing. The majority of the mount is still aged rubber. You'll probably see better results in stiffness from one of these: https://store.034motorsport.com/moto...2-n54-n55.html https://www.ecstuning.com/b-turner-m.../002445tms~dk/ __________________ 2015 Cosmic Blue Metallic Wrapped X3 35i ///M Sport Full 3M Vinyl Wrap \| Flat Black Grilles
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01-01-2021, 06:08 AM	#9
HDBoss Enlisted Member 13 Rep 33 Posts Drives: ‘11 F25 N55 Join Date: Jul 2016 Location: Belarus iTrader: (0)	Great job! Here is mine - right side mount after 150k km... I just changed it to a new one. Attached Images __________________ My mod list: '11 F25 35i // BM3 Stage 2 93 Oct \| PS2 \| GFB DV+ \| VRSF 5" HD IC \| FTP CP+BP \| FTP F10 inlet \| K&N Drop-in & HP-7014 \| BMS OCC \| VTTO Breather \| Stage 2 LPFP \| Helix OD HPFP \| Custom Brakes M5 F10 \| 27mm Master brake cylinder \| M sways \| KW var2 \| Supersprint full exhaust \| VRSF catless downpipe \| HRE 21" P40SC \| Alpina spoilers
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