5 Speed Group N manual transmission mount! Stiffen up your mount! (98-08 Forester, 93-14 Impreza/Wrx, 05-09 Legacy GT)
When it comes to factory rubber bushings noise suppression and comfort are high priorities, while shifting feel and enjoyment take a back seat. After many years of service your bushings will become more compliant, i.e. allowing further back and forth movement. This will give the shifter sloppy feedback and can even cause driveline issues if not taken care of quickly. Other noteworthy issues from a weak trans mount are clunking noises when leaving a stop or shifting.
Instead of replacing that tired old mount with another soft squishy unit let’s take a look at the Subaru Group N unit. Visually the two are very different as the stock factory mount has a large open area to lessen the amount of noise and vibration into the cabin. This comes at the price of stability. The Group N mount takes care of this with much more surface area and on top of that a stiffer urethane.
For this install in the manner described you will need on a 14 mm socket, an extension or two, anti-seize isn’t necessary but is nice, and your ratchet. If your car is of ample height like the lifted Forester you won’t even need jack stands but a jack is needed to hold the trans in place when taking out the bolts and nuts. There are many ways to do this install but this would be the minimalist approach. Taking out the least amount of bolts to get you back on the road and enjoying your modifications.
Not much in the parts bin for this. Just the 5 Speed Group N transmission mount. If you would like to replace the squishy transmission bushings this is an excellent time and can easily be done at the same time.
On to the install, with your trusty jack in hand we will start by lifting the vehicle into the air. Or if your vehicle is tall enough you can just leave it on the ground like I did. Either way you will take a cushion or piece of wood and use your jack to support the transmission.
With those two removed you can take out the bolts that are in the center of the cross brace. With these removed we can move to the rear brace bolts.
Removing the weight off the mount you now began to unbolt the transmission mount bolts. The two at the rear cross brace are 14mms bolts, much like every nut and bolt in this replacement.
Now you can go back to the two studs that bolt the transmission brace and mount together. With these removed the brace should start to slide down and you can maneuver it down and access the four bolts that attach the mount to the trans.
Taking out these four bolts will remove the mount from and we can start putting in the new mount. Now snug the four bolts up but do not fully tighten/torque them yet.
With a little bit of play in the mount you can slide the brace up and start the nuts on the studs. Once you install the nuts on the front brace studs and trans mount studs it will suck the brace up.
With those nuts installed move the jack to the trans brace to hold it in place and line up the rear bolt holes. Then you can install the rear bolts by hand making sure that the threads are fully engaged and threading in easily before tightening them up.
With each and every nut and bolt in place you can now run them all down to the proper value. Remembering the transmission mount was left loose to allow the brace to be placed properly.
You can now remove the jack and jack stands if you needed to use them. Taking the vehicle for a very short test drive to make sure everything is right and tight.
Congratulations! Enjoy the new solid feeling when shifting and bit more noise in the lower gears as the mount reverbs through the car.