How To: DIY filled motor mounts

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2003.5 silver Mazdaspeed
The photos of the mount are from my Mazdaspeed Protege but I'm sure this will work for any mount that has the same type of construction. The stock mounts are made from very soft rubber and have large air holes to help isolate the engine vibrations from the passengers in the car. Filling in these air holes will reduce the amount the engine will rock but may increase vibrations in the car. I used epoxy on a past car and this really made a difference in the way the car drove. Everything inside the car vibrated but it was a Dodge Neon so that isn't really all that uncommon(freak) . I used silicone this time and it seems to be a nice compromise. Plus if you don't like it you can always take it out and try epoxy. I think once it is filled with epoxy it's there to stay.

Materials that can used to fill with listed from softest to hardest
Silicone (dries to a soft rubber)
pros: easy to find, thick so it won't ooze all over, pliable so it stays in place,cheap
cons:takes longer to dry
motormount6.jpg

Liquid urethane (dries to various stiffness of rubber) (thanks OKI BOY)
pros:availiable in different stiffness, dries fast
cons:may breakdown, might be to runny for paper plate? (CustomMSP said he used 3 layers of tape to close off one side. Going right over the center hole. Thanks for the input!)

can't find a picture

Window weld (dries to a hard rubber) (thanks DSM2MSP)
pros:fast drying, stiff, holds up to car enviroment
cons:might be to runny for paper plate? (other ideas?)
motormount7.jpg


Epoxy cement (dries like a piece of hard plastic)
pros:dries very fast, thick consistancy is easy to use)
cons:has no give at all (could be a plus or minus depends on what you want)
motormount8.jpg


Materials needed:
filling material
Paper plate
drying time


1.) Remove the motor mount.

2.) Cut tab that sticks out below the top of the metal to allow mount to sit flush on paper plate.
motormount1.jpg


3.) Cut hole in paper plate to stick metal in center of mount thru the plate.
motormount2.jpg


4.) Place mount on plate with metal sticking thru plate. The point of this is to keep the silicone from going all over the place.
view from bottom
motormount3.jpg

view from top
motormount4.jpg


5.)Fill mount with silicone. (or epoxy or ????)
motormount5.jpg


6.)Let it dry. It was like 80 deg. out the day I did mine and I let it dry about 2 hours before I put it back in the car. I didn't drive the car until the next day.

I havn't noticed any increase in vibration compared to stock and it is a lot easier to drive now with the silicone.
 
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Nice DIY, another common thing to use is window weld, a little stiffer than the epoxy and silicone. I did it on my vr4..made a nice difference.
 
Demonic-Speed said:
Nice DIY, wrong forum though...It will be moved soon:)
I know just hoping more people would see it here. Any guess on how long till its moved.(outie)
 
DSM2MSP said:
Nice DIY, another common thing to use is window weld, a little stiffer than the epoxy and silicone. I did it on my vr4..made a nice difference.
Cool I'll add that to the DIY. Epoxy once dried was like a piece of glass. What is window weld like? Did you have a Gallant or a 3000gt VR4?
 
most people that did the DIY motor mount stiffening on the spec v's used either 3M window weld or liquid urethene.

silicone ended up being too soft and not killing enough of the wheelhop.
the window weld was supposed to be a big messy PITA to work with though...

urethene sounded like the best option, as it was availible in different grades of final stiffness and ease of use.
 
my MM filled with liquid urethane has separated at the center ring and is back to being soft like the stock because of the empty space around the ring. What you have to do is refill with urethane again at the cracked places.
 
CustomMSP said:
my MM filled with liquid urethane has separated at the center ring and is back to being soft like the stock because of the empty space around the ring. What you have to do is refill with urethane again at the cracked places.
What did you use to keep the liquid urethane from leaking out when you poured it in?
 
tape, just tape everything up on one side of the mount including the center ring. Do Not make any cut outs and go over the tape like 3 times.
 
nice.. it is probably still to soft though. b/c the stock rubber is pretty soft to begin with, so even if it were SOLID rubber with no holes, it would be soft. the aftermarket AWR ones are pretty stiff..
 
i did this with silicon to a mazdaspeed #3 motormount as well. silicon is still pretty soft, but it seems like it helped reduce the movement a bit.
 
uclap5 said:
i did this with silicon to a mazdaspeed #3 motormount as well. silicon is still pretty soft, but it seems like it helped reduce the movement a bit.
how difficult is the removal of the #3 mm?
 
I used window weld on my back and #3 motor mount. Cured the wheel hop with the use of an awr front mount.
 
mspeedpro said:
how difficult is the removal of the #3 mm?

not too bad.

you will need a 6 inch extension, 15 mm (i think, could be bigger) deep socket, and i think a 14 or 12 regular socket.

took a good pretty large ammount of force to get off the nuts on the engine, but after that its pretty cake.
 
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The liquid urethane actually works very well, I swapped rear AWR my for filled mount mount and didn't notice any difference between the two as far as engine lash goes. I went from major vibration to zero vibration with my filled mount(80a shore hardness). But in about two weeks once the urethane separated from the center ring my engine started lashing like hell again and the shifting became a b**** aswell because of the engine movement. So now I'm ready to buy Kooldino's MM inserts.
 
Monuts

Has anyone tried this set-up through the winter months? Curious as to what the ride quality is like. I live in the Northeast.
 
rahrcr said:
Has anyone tried this set-up through the winter months? Curious as to what the ride quality is like. I live in the Northeast.
The stiffer mounts make the car easier to drive and makes it very nice in the winter. With silicone I havn't noticed any increase in vibration. I'm sure with stiffer filler your going to start noticing some vibration. With silicone it makes the car the way Mazda should have done it. If your going with lots of mods I would surgest something stiffer than silicone. I have never really had much of an issue with wheel hop. I've only hopped a couple of times. But since I have turned the boost up I've hit fuel cut a few times and with the O.E. mounts it's just nasty. You can feel the engine rock and slam back and forth. Silicone has helped this.
 

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