kastle
01-13-2002, 02:48 PM
<IMG src=/mods/impreza/images/stitm1.jpg BORDER=0 ALT="Shiny and New" WIDTH=554 HEIGHT=282>
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I had some really harsh expectations about the difficulty of this install. In reality, its probably not something I would want to attempt on my garage floor. We had access to a lift, air tools, and just about anything we could conceive of to make our job that much easier.
<P>
But why put in a STI transmission mount anyways?
<P>
It turns out that Subaru places soft rubber engine and transmission mounts into the Impreza 2.5RS to help isolate the cabin from the dreaded NVH. It also has the downside of causing a lot of flex in your drivetrain, but its a compromise Subaru made to help isolate the cabin from the rest of the car. This is exactly the type of thing we don't want in a street/track car.
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<TR><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm2.jpg WIDTH=589 HEIGHT=295 BORDER=0 ALT="Transmission Stand">
</TD><TD VALIGN=MIDDLE>
Because we are going to remove all the transmission mounts and crossmembers, its important to place a stand to keep it all from falling. While the transmission <B>is</B> mounted to the engine, the engine mounts will flex and allow the transmission to droop if not supported. This causes all sorts of alignment headaches for those trying to do the install. By placing a brace under the tranny, it prevents the transmission from becoming misaligned in relationship to its mounts when you remove them all.
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<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
In this picture, you can see where the old transmission mount bolts to the transmission (black arrows) and where it bolts to the transmission cross members (yellow arrows) In order to even get to it, we are going to have to remove the front transmission cross member, and the bolts holding the middle cross member in place from the rear transmission cross member. The transmission braces are arranged in an <B>H</B> pattern. With the front and rear transmission cross members providing the support for a middle brace that directly connects to the transmission mount. It is this middle brace that must be removed or swung out to the side so you can directly access the tranny mount.
</TD><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm3.jpg WIDTH=480 HEIGHT=360 BORDER=0 ALT="Stock Mount">
</TD></TR></TABLE>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm4.jpg WIDTH=581 HEIGHT=246 BORDER=0 ALT="Disconnecting the braces">
</TD><TD VALIGN=MIDDLE>
Here we have removed the front transmission crossmember, and have removed 1 bolt from the rear member, and loosened the other. Also remove the nuts from the tranny mount that are attached to the brace, and swing it out of the way. You can now directly access the four bolts that connect the mount to the transmission itself.
</TD></TR></TABLE>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
Here are the two mounts side by side. You can see why the STI mount is so much better. Once you have the old mount removed, simply bolt up the new one, and re-install all your cross members. This modification really does improve the overall feel of the car.
</TD><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm5.jpg WIDTH=372 HEIGHT=351 BORDER=0 ALT="Comparison">
</TD></TR></TABLE>
<br>
I had some really harsh expectations about the difficulty of this install. In reality, its probably not something I would want to attempt on my garage floor. We had access to a lift, air tools, and just about anything we could conceive of to make our job that much easier.
<P>
But why put in a STI transmission mount anyways?
<P>
It turns out that Subaru places soft rubber engine and transmission mounts into the Impreza 2.5RS to help isolate the cabin from the dreaded NVH. It also has the downside of causing a lot of flex in your drivetrain, but its a compromise Subaru made to help isolate the cabin from the rest of the car. This is exactly the type of thing we don't want in a street/track car.
<BR><BR><BR><BR>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm2.jpg WIDTH=589 HEIGHT=295 BORDER=0 ALT="Transmission Stand">
</TD><TD VALIGN=MIDDLE>
Because we are going to remove all the transmission mounts and crossmembers, its important to place a stand to keep it all from falling. While the transmission <B>is</B> mounted to the engine, the engine mounts will flex and allow the transmission to droop if not supported. This causes all sorts of alignment headaches for those trying to do the install. By placing a brace under the tranny, it prevents the transmission from becoming misaligned in relationship to its mounts when you remove them all.
</TD></TR></TABLE>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
In this picture, you can see where the old transmission mount bolts to the transmission (black arrows) and where it bolts to the transmission cross members (yellow arrows) In order to even get to it, we are going to have to remove the front transmission cross member, and the bolts holding the middle cross member in place from the rear transmission cross member. The transmission braces are arranged in an <B>H</B> pattern. With the front and rear transmission cross members providing the support for a middle brace that directly connects to the transmission mount. It is this middle brace that must be removed or swung out to the side so you can directly access the tranny mount.
</TD><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm3.jpg WIDTH=480 HEIGHT=360 BORDER=0 ALT="Stock Mount">
</TD></TR></TABLE>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm4.jpg WIDTH=581 HEIGHT=246 BORDER=0 ALT="Disconnecting the braces">
</TD><TD VALIGN=MIDDLE>
Here we have removed the front transmission crossmember, and have removed 1 bolt from the rear member, and loosened the other. Also remove the nuts from the tranny mount that are attached to the brace, and swing it out of the way. You can now directly access the four bolts that connect the mount to the transmission itself.
</TD></TR></TABLE>
<TABLE WIDTH=100% BORDER=0>
<TR><TD VALIGN=MIDDLE>
Here are the two mounts side by side. You can see why the STI mount is so much better. Once you have the old mount removed, simply bolt up the new one, and re-install all your cross members. This modification really does improve the overall feel of the car.
</TD><TD VALIGN=MIDDLE>
<IMG src=/mods/impreza/images/stitm5.jpg WIDTH=372 HEIGHT=351 BORDER=0 ALT="Comparison">
</TD></TR></TABLE>