# When you mounted your motor...did you use rubber bushings?



## stealthE (Jan 31, 2016)

I am using an encoder end mount, and I have the option of building my brace using the existing rubber factory Jeep motor mounts, but it would be just a little bit easier to not use them. But how much vibration comes from an electric motor? Should I retain them? Did you?


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## madderscience (Jun 28, 2008)

I used aftermarket urethane bushings to replace the original rubber ones, but yes, you still need flex bushings of some sort. I built a subframe that attached to the original engine mount points and bolted the motor and diff to that.

It isn't just the vibration of the motor/drivetrain. The other issue is that the body of any vehicle flexes a little bit and with a very rigid object (motor, tranny, or engine) bolted into place it will promote fatigue at the mount points unless something is done to allow a little movement.


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## Duncan (Dec 8, 2008)

I agree with Madder - you want some compliance
BUT
The factory rubbers are for an IC engine and they are very soft to take out the bang bang bang at idle
You really want something a lot stiffer


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## Matej (Dec 4, 2015)

Coming from the drift/240SX community, many people solid-mounted their ICE engines and transmissions with aluminum mounts.
That is something I would have never done, but I decided I will solid-mount my electric motor along with the transmission.


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## twright (Aug 20, 2013)

If you don't use some sort of rubber isolation, you will feel/hear some vibration and growling coming from the motor to frame interface.


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## Moltenmetal (Mar 20, 2014)

I mounted my AC50 face mounting bracket directly to the frame with some 1/2" thick rubber pads between the bracket and frame and again between the bracket and the through bolts. I get more noise from my transmission than I do from the motor. 

I second Duncan's statement- you don't need the range of motion that the original ICE mounts provide, so they're not the best choice. And if they're not designed for the torque your new electric motor can provide, it's not just an annoyance to have a motor mount fail on you. It's really not something you want to happen.


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## Yukon_Shane (Jul 15, 2010)

I rigid mounted the motor in my first conversion and I didn't like it. There was a bit of noise and vibration and the controller "ringing" seemed to resonate through the car.

I ended up redoing the mounts later and it was a lot nicer. 

I think it will kind of depend on your application though. If you want a smooth running "daily driver" then you should probably us isolating motor mounts, if your racing then who cares...


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## evmetro (Apr 9, 2012)

The sound of a transmission is incredible if you don't isolate it with something. Lotsa rubber sounds the best, poly bushings are louder, and solid mount is just plain loud. The torque of an electric motor can indeed tear up the ICE rubber mounts in a hurry, so it it is a trade off of sound vs mounting integrity. I am building an electric caddy right now, and have the motor and transmission mounted to a cradle with a combination of rubber and poly, and then the cradle is rubber mounted to the chassis. I don't like to hear all the noise in an EV. My vacuum pump is double isolated the same way to keep it quiet as well.


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## bigmouse (Sep 28, 2008)

I didn't use my stock engine mounting locations, but I did use rubber mounts. I found some engine mounts from a Mitsubishi that bolt on. Made some brackets and had them welded to the frame rails. I haven't run it yet so I can't tell you how quiet/noisy it is.


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## mizlplix (May 1, 2011)

I guess I am a sinner as I solid mounted everything.

On my first car, it was rubber mounted.
On my second car it was polyurethane mounted.
My third car is solid.....With no real problems, BUT it is an open car with the wind in your face. It has been almost 4 years and no cracks or other problems. 

If your transmission is noisy then you have a worn transmission. Fix it.

If you have controller ringing, then you have a DC controller, it will still ring even with rubber mounts.

My biggest problem was over thinking everything and costing money and time for no reason. Simple works best.

Miz


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## Caps18 (Jun 8, 2008)

I solid mounted it. We shall see if this works or not once the motor is connected to the battery. I used part of the original mounts and a CANEV ring type mount. The transmission has the original rubber mount, and the motor is bolted to the mounting plate and that is bolted to the transmission housing.


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