DIY trans-mount bushings

[Garrison]

Hey hey hey,

Allow me to begin with a confession...

I loathe transmission slop. I despise the feeling of the transmission flobbering its way back and forth, whenever I clutch out, or hit the gas harder than I should, or really anytime at all. So, after searching through a bunch of F/S and a few DIY forums, I learned that you can buy a used, shot trans-mount, fill it with epoxy and make yourself an equivalent of the of the Group-N trans-mount, for about half the price. I also bought a tranny mount.

Group-N mount, for reference:
https://sl-i.net/FORUM/images/imported/2011/10/DSC07523-1.jpg


What you will need:
1 - caulking gun
1 - tube 3M Window Weld (or your preference) ($19.99 at advance auto)
1 - roll duct-tape


This is for you guys who want to follow in my stead (you could probably even improve upon my methods.
For those of you who are curious as to why I used 3M Window Weld instead of a poured/mix epoxy (which would also work), it is because of hardness. Window Weld is about a 6a on the hardness scale; epoxy is closer to a 9a. I wish to keep NVH to a minimum. Simple right?
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0190-1.jpg

So, for starters, clean the hell out of the used trans-mount. Use soap, water, degreaser and a wire brush (or similar) and really clean the junk of there. There will probably be a lot, but you should be left with a regular trans-mount with no bushings and only 2 somewhat rubbery posts. Keep those, don't cut them out.

Before:
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0191-1.jpg

After:
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0192-1.jpg



Dry it off, and mask the a side off with duct-tape. Begin filling the center portion with Window Weld. Go slowly to avoid air-bubbles, feel free to really pack the goop in there deeply. When you get finished, you may opt to continue, I did. I proceeded to do the other oem bushing location, the two ears covering the center support. I lined and filled both of these to the brim.

https://sl-i.net/FORUM/images/imported/2011/10/IMAG0194-1.jpg

Sides:
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0195-1.jpg
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0196-1.jpg

Then, I went one step further and layered one last support, covering and connecting the whole collective of Window Weld. I did this twice. Afterwards, I used some cardboard to level out the Window Weld (this stuff is ridiculously hard to clean, try not to make a mess):

https://sl-i.net/FORUM/images/imported/2011/10/IMAG0198-1.jpg
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0197-1.jpg


Now, just wait three days for the 3M to harden before you install. For those wishing for slightly less NVH than I will have, do not 3M the ear supports, just leave them blank or use a softer material. Hope this helps you guys, and here's the link I used for this information: http://www.3gwrx.com/forum/index.php/topic,14803.0.html


EDIT: I decided to go ahead and fill it completely, in two segments. I don't recommend this, as it won't be as sturdy, but anyways, here you go.
Front Facing:
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0229-1.jpg

Rear Facing:
https://sl-i.net/FORUM/images/imported/2011/10/IMAG0228-1.jpg

[chuckthefuk]

Oh nooooes... Whats next hockey puck engine mounts :-/ Damn honda DIY..

:-D This is good but not Group N ... the metal mount is thicker then the OEM unit.

[Garrison]

Probably not better, no... but a significant improvement, especially if you were to make the whole thing solid and "brick"-like

[Huffer]

Good DIY. Pics and description are spot on for the methodology.

You can also do a similar thing with the Pitch Mount... and if you use plastic wrap around the unit you can let it cure a bit, then unwrap and "shave" it flat to make it look better.

[Matty2Hotty]

Yeah on the Impreza write ups I seen they fill in the entire bushing. Any reason not to as mentioned like a brick?

[d1giPhux]

As stated, you could use aluminum tape to make it completely flat if you really wanted. It would only really be an aesthetic thing, but might make it look more professional. Either way.. cool idea!

[Garrison]

Not filling the mount is just reducing the nvh, but in retrospect, if I had thought I had enough in the 1 tube; which you do, I would have filled the entire thing. I'll report back on the difference this makes and then suggest which I would do again.

[Wiscon_Mark]

You can also do a similar thing with the Pitch Mount... and if you use plastic wrap around the unit you can let it cure a bit, then unwrap and "shave" it flat to make it look better.

oooh, I might do this! Very easy mod.

[Garrison]

Well, my mechanic won't be able to get to me until next tuesday so because I've got plenty of time left, I'm going to go ahead and fill it up to "Brick" proportions. I'm going to do the same process as above, except I'm going to go at it from the other side.


Edit: Also, letting it cook in the sun seems to help harden it quicker.

[chuckthefuk]

Are you not worried about adhesion?

When this stuff cures its not exactly a porous contact surface...

Just saying.. u don't want to get messy to find out the new section that cured just falls right if u move it..

-Chuck

[Garrison]

Eh, even if it does fall out, which you're right is completely possible (though I would guess improbable [this sh*t is ridiculously adherent. Nigh impossible to get off your hands, for instance]) I'll still have my orginal fill, which should be just dandy. Either way, it's done now.

[chuckthefuk]

Agreed however.. Its the same concept as super glue.. When you touch it to your skin it sticks instantly but if you lay a glob on a flat surface you can easily pry it off once dried with little effort since it could not adhere to anything.

[d1giPhux]

You could always drill small micro-holes into the solid portions.. then fill it. This will create 'tabs' to hold the new rubber section into the old rubber section. It might work..

[Garrison]

That's a great idea dude. I'm unfortunately unable to modify mine any further to incorporate it though, but I would recommend it if someone else were to do this, just for a little extra insurance.

[Garrison]

I've allowed the mount to sit in the sun for a few days now, cooking it basically, and it has sped the process up immensely. Before, I kept it in a concrete floored room, essentially a constant 60 degrees; the initial top layer was harderened, but I could feel bubbles, or soft spots underneath. I now feel the "brick-like" properties that were mentioned in the impreza write-up. I hope the increase in NVH doesn't suck too much. Will update with pictures later today

[Garrison]

I've got the mount in the car, and yes, NVH is increased. But not terribly so, in fact the only difference I notice is that my dash vibrates around 5500rpm when stomping it. That and the shifter vibrates more violently than it did before at WOT.

If you want to keep the feel OEM, then only fill the middle section and the "ears" of the mount. The shifting in the car is very, VERY direct now.

[Garrison]

Update #2:

While driving around normally, there is no change in the feel of the shifter from that of stock. The rattle I mentioned before is no longer present. The only difference is the feeling of vibration through the shifter while stomping on the accelerator. Otherwise, shifter feels normal, with little to no vibration. I'm voicing my opinion here, but I recommend this mod if your tranny mount is toast.

[Garrison]

Update #3:

Having broken in this mount for ~800miles, the shifter feels like stock when not hammering it, and only vibrates firmly when flooring the acceleration pedal. Tranns slop is nothing, (except it is still felt when lifting from high-rpm to braking).

[Garrison]

Update #4

20,000 miles have passed and the mount is still holding up well. Shifts are still smooth, and no weird rattles from the trans.

[chuckthefuk]

ha-za!

[1055]

I went one steo further than you on my tired, 170,000 mile mount. I found some nuts that fit perfectly between the center portion and ears of the mounting portion, and welded them in. Best mod for free ive ever done. Nvh increase is minimal and it feels 100% better.

[Garrison]

^^^ That's an awesome idea!

[1055]

It doesn't look pretty as the 13 year old metal is a bit pot marked and pourus, but it works well.

Ill get a picture or two next time its up in the air.