DIY Urethane Motor Mounts, Why spend $200, you can DIY for $30 Rating Options

[Toecutter]

Introduction:

This DIY describes the process of filling the XD's motor mounts with urethane.

The XD has a lot of “wiggle room” in the stock motor mounts. This causes serious wheel hop issues on “power launches”, usually not a problem with the stock XD However this could be a serious problem for those that have gone FI. Wheel hop is not my major concern. For lack of a better way to explain it, I am looking for a way to better connect the gas pedal to the pavement for autocross. Bear this in mind before you proceed. The XD's “mushy” motor mounts are made for a quiet and comfortable ride. Should you use this procedure you will have increased NVH in the passenger compartment.

To avoid too much NVH, I have chosen to fill only the front and rear motor mounts. Besides filling the side mounts offers little benefit.

I looked for urethane motor mount inserts. I have only found one for the XD and it is bloody expensive. The urethane used here can be had for $20-$40 depending on where you get it.

Tools & Supplies:

* 14mm socket wrench
* 14mm combination wrench
* Exacto knife
* duct tape
* oil drain pan, dishpan, etc...
* kitty litter, oil dry, sand etc...
* liquid urethane
(I used 80A liquid urethane: P/N: 8644K11 from McMaster Carr)
* MEK (methyl ethyl ketone)
* (4) jack stands
* hydraulic jack

Estimated time:

* 1-2 hours to complete
* 2 days for urethane to cure

Procedure:

1)Jack car up and support with jack stands. Car must be high enough for you to easily get to the rear engine mount.

2)Remove rear engine mount (part number 21930R in attached image)
* Remove bolt number 21920 and nut 1339GB
* Remove the three bolts holding the mount to the sub-frame

3)Remove front engine mount (part number 21840) using same procedure described for rear mount.

NOTE: it is not required to support the engine when removing these mounts. The engine's weight is supported entirely by the upper side mounts (P/N: 21670 & 21930R).



Removed mounts:


4)The motor mounts have flashing between the voids. To get good fill with the urethane, use a sharp Exacto knife to cut this flashing out.

Cut out the flashing:


5)Clean the rubber in the mounts using MEK (methyl ethyl ketone).
MEK is available at most hardware stores.

Flashing removed:


6)Using duct tape, or similar, tape one side of the motor mount. Try to seal as good as you can to prevent the urethane from leaking once you have poured it.

Taped mounts:


7)Put kitty litter in a pan, and set motor mounts in it, tape side down. The kitty litter allows you to level the motor mounts in the pan and will absorb any urethane that may leak past the duct tape.

Here kitty kitty:


8)Mix urethane per manufacturer's instructions and pour into the motor mounts.

1lb 80A liquid urethane kit:


Filled mounts:


9)After a few hours you can remove the motor mounts from the “litter box” and remove the duct tape. However, you need to wait for at least 2 days for the urethane to cure to 80%-90% of its full strength. I would not put the mounts back into the car until 2 days have passed. By the way, the urethane reaches full strength after 7 days.

Finished product:




Thank you for reading. I hope that you find this DIY useful. Happy motoring!

There is always more than one way to cook a skunk; also see KeWLKat's DIY: Solid Motor Mounts.

[cobas]

Another great DIY... how do you know about this stuff?

Also, you should add a warning that a fresh box of cat litter is irresistible to most household cats... beware what will end up in you mounts.

[Toecutter]

Thanks Cobas! To answer your question. I'm old, at least according to my wife, and some things just make sense to me. Also, A LOT of lurking in forums, and other websites helps.

Also, you should add a warning that a fresh box of cat litter is irresistible to most household cats... beware what will end up in you mounts.

LOL... My cat stays in the house... no chance of poo filled mounts.

[Toecutter]

I didn't know where to put this DIY Mitch. It doesn't fall into any of the other categories. Anyway, could you put it up on the DIY page when you get a chance?

[Toecutter]

I drove with the filled motor mounts today and found it very interesting. NVH is definitely greater at idle, but at anything other than idle it disappears. Acceleration feels a LOT smoother. I can really feel now just how much power the Beta II is lacking...Boo Hoo! There used to be a bit of a lag when the motor mounts loaded up... this is now gone. My shifter doesn't move about at all anymore. It wasn't at all bad in the first place, but less movement is better. Finally, the exhaust system used to shift quite a bit on hard launches. This movement has been eliminated.

Overall, I am very pleased with this mod, and I believe that it will serve it's intended purpose of helping me to be smoother on the autocross circuit by allowing me to feel the road better with my right foot.

[Gregster]

I did this mod on my Neon, and it was great. However, i'm concerned about warranty issues from this mod. What "beef," if any, can a dealership give to void powertrain?

[Toecutter]

I don't think that the stock mounts do much to protect your powertrain. True they buffer the torque a bit, but only until their loaded. They are mainly to isolate the cabin from NVH (Noise Vibration Harshness). However, I imagine some service managers would not like it.

Also, you powertrain may actually benefit from the stiffer mounts if you routinely launch hard. The wheel hop induced because of the stock mounts can really tear things up.

[Bigs]

Good stuff man! Mitch will add it to our DIY page for sure!

[02CanGT]

There is another potential benefit from this mod, if it applies to you:

I removed my rear roll stop on the transmission to do this, and after cleaning and inspection, found one of the rubber 'spokes' was cracked, almost 1/2way through. Had I left it, it would have eventually shorn completely, putting the load on the remaining arms which would have also potentially worn faster due to extra load.

I filled my mount, and it feels so much better. I will do the front when I am bored.

Another great DIY, metacarpal-deintegrifier!

[fgummett]

Great DIY

Now I just have to figure a way to be without the car for 2 days or see if I can pick up some spare motor mounts at a scrap yard. Would any Beta II and/or Beta engine mounts do for an '05 GT hatch..? I assume this is not a cheap replacement part at the dealers? With increased NVH it might be nice to return to stock for sale etc...

I noticed these Motor Mount Inserts... at Energy Suspension but they don't list for Hyundai... anyone know if we share motor mounts with another manufacturer... Mitsubishi perhaps..?

Thanks

[reaperangel01]

anyone know if we share motor mounts with another manufacturer... Mitsubishi perhaps..?

Kia is the lower-end Korean make (same manufacturer as Hyundai). You might be able to find some from them.

[chris43230]

see I have heard so many ways to make the mounts "stronger" and i'm trying to find someway to help mine. My mounts are original to the car and are cracked and I cant afford to replace them and the local junk yard isn't much help. Now I was interested in trying the liquid urethane for the front and rear engine mount and filling the side engine mount and transmission mount with polyutheranne caulk. I heard that using Polyurathane caulk (liquid nails) would work as well. I gotta do something because my engine shifts too much in my engine bay and it scares me. And if the caulk wouldn't work if i filled all the mounts with liquid utethane would the car really shake horribly? Please help folks!