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I forgot how much urethane I used for my set when I did them. That is including the (drilled) brown plastic baffles inside. I know 1lb order from McMaster-Carr will be enough to do one pair. How much of that 1lb did you guys use for your application?
Last edited by SayNoToPistons; 05-12-2013 at 07:25 PM.
I had about half of what came to me to start with.. I was bummed i put the hardener in the can rather than just mixing what I was going to use.. But I didnt know how much I would be using at the time.
I just installed my poly filled motor mounts today. The difference in the shifter feel is incredible. I am getting a fair amount of vibration when moving from a stop, just for about the first 500RPM. Everything else is buttery smooth. I used the 80A. Anyone else experiencing the same thing? Its not enough not bother me, just something I noticed.
decided to do this while my engine is out of the car.. I went with the window weld for the filling, does anyone know how long it takes for the window weld to fully cure? ive read it takes 7 days for the 60 and 80 but havnt seen anything on the window weld cure time
Unless the "window weld" is low viscosity (which I highly doubt), it won't work no matter what shore rating it is. It needs to be pour-able to the extent that no air bubble/chambers will be prevent in the mount. It'll just shear with the tension and compression, then you'll have a bad time.
Unless you like having a bag time, don't use "window weld". Leave that to the ricers.
Also just wanted to note that I have done this DIY at least two or three times in the past and always went smoothly thanks to Team's excellent instructions. Today sucked. Mounts off of an 07 MT -- totally different somehow. For one, the RH and LH looked identical after cutting off the rubber tops. I freaked out for a few moments, thinking someone had replaced my LH mount at some point and I had two RH mounts. Identical markings on the rubber freaked me out some more. Took me a few moments to recall they are actually marked LH/RH on the metal part and I do indeed have one of each. Second issue I ran into is the 1 1/4 bit ended up being too big. I recalled the top layer to expose the rubber plug being very thin, but I drilled and drilled and never got through. I ended up taking a 5/8" bit and drilled through into the underlying cavity very easily thereafter. Prodding around in there with a small bit revealed that the center cavity is just slightly larger than that. Drilling the 6 holes at the edges still went as expected, could feel the bit punching through the layers of honeycomb; but somehow there is a lot of solid plastic between that and the center.
FYI for anyone else having trouble.
Would appreciate anyone's input on the solvent before I fill tomorrow AM.
there’s a threaded metal piece embedded in the center. If you google “broken rx8 motor mounts” and search through the images you can probably find all kind of pics of how they’re configured internally.
I had a set that had that similar centre that you are describing, I initially drilled and drilled and did not get through, but I managed to pull the rubber section out by pulling it through a small hole.
What I found was that there is a steel ring section that is in the middle there, which can be removed and then the rest was fine.
Also the rubber outer cover is also held in position with a steel ring, that can also be removed.
One other thing I found that seems to work pretty well, is cleaning the oil out be soaking the engine mounts in detergent and hot water. A lot of detergent, just pour it into the mounts and then into a bucket of hot water and just let them soak. Do that a couple of times and they come out nice and clean.
Not sure I’d recommend removing that piece since it likely limits how far the top rubber piece moves. Eventually even filled mounts seem to end up tearing the top rubber part loose. Detergent and hot water makes sense though. I din’t have that option at the place I kept my car then, but I couldn’t have taken them home and done that in the sink.
Hmmm... I'm glad I didn't get that far to expose any metal parts inside of the plastic, but still I hope I didn't affect the integrity of the mount adversely in any way. Sounds like it is a revised part and somewhat beefed up? It's going to be an N/A street car though, so not overly worried.
Thanks for the tip on the detergent, I will do that.
Here's pics if anyone cares to see. Initially the top surface was completely flat on both. The larger circles are first two attempts with 1 1/4 and 1 inch. The middle holes done with 5/8 bit. The LH side is irregular since I worked at the edges to show the size of the cavity, which isn't much more, seems still smaller than 3/4"
The steel ring section that I found in there is just a push in insert, but it is below the first layer of the brown plastic stuff. Once it is removed it gives you easy access to be able to clean out the rubber section of the mount.
I've just received another couple of mounts today, so I will cut them open tomorrow and see if they have the same steel ring insert. The previous set that I did before did not have the steel insert.
I also tie the alloy mount into the urethane mixture by drilling right through the alloy threaded section and taping it with the same thread as original which is 10mm x 1.25 and them adding a 45mm bolt that sits into the rubber cavity and once you pour in your urethane mixture, which then attaches itself to the bolt to help hold the whole lot together, so hopefully the alloy/rubber top section will not tear away from the steel section. I guess only time will tell.
Has anyone tried to fill mounts that look like this? These are $100 amazon mounts that failed after 9 months and 3000 miles. My original mounts failed and I bought these to use temporarily while I filled my OEMs. Amazon gave me a full refund and let me keep the leaking mounts.
The filled OEMs are now working fine but I might keep these for a backup. I removed the outer rubber seal and drained what oil remained. Inside is a hard rubber part with the swirl that is in the picture. It is hollow under the rubber which is maybe 1/4 inch thick. I was going to trash them but though I would ask if anyone had experience first. I don't want to waste time and money on these needlessly. Besides my filled original mounts will hopefully last a while.
Just curious if anyone has even seen these. There are lots of cheap mounts on ebay for around $100 which probably look like these.
the only thing I’d caution you on for modifying the OE mounts is drilling too deep. If you end up drilling into the top rubber piece it will likely crack and fail sooner.
You can buy heavier duty engine mounts from Mazda Motorsports, but they’re pricey.
05-12-2013, 07:17 PM
