I was surprised that I did not see more people discussing issues with setting the G37 (or 370z) manual transmission (MT) on a transmission jack. Videos for clutch work pretty much breeze over or do not mention the issue with the transmission stability and lack of a flat spot to secure the transmission. Hopefully this post will help others who attempt such work.

Recently, while changing my clutch, I struggled to get the transmission to sit securely, even with two different types of transmission jacks. Straps weren't effective and were difficult to maneuver in the tight tunnel space. The jacks I used—one a basic scissor model with a V-groove and the other a more advanced model with a flat contact surface and clamps—both had the same problem. Unlike automatics or some other MT cars, my transmission had no flat or level spot. It just balanced precariously on its various uneven protrusions, making it impossible to secure for removal and even worse for reinstallation.

I tried using wood and rubber wedges, along with various tie-down straps, but the weight and awkward shape of the transmission always caused it to shift. It's significantly heavier than transmissions in many other cars, which only added to the difficulty.

Finally, out of frustration, I flipped the transmission over. Using a table saw and a drill, I cut and screwed together pieces of wood to create a custom template base. This wooden base fit perfectly into the jack, creating a snug and stable platform for the transmission. Reinstalling the transmission back into the engine took only a couple of minutes, with the jack's alignment ***** making the process incredibly easy.

You can see the bottom of the jack and the template as well in the pictures. The template I made took a while to get it cut exactly, but it fit perfectly- no further wobble, shake, shifting or time wasted with the alignment). Unfortunately I was focused on completing the clutch job, so I do not have pictures of the transmission in the jack template. With the template base as shown, the bell housing would protrude out of the front of the jack (although it may not look like it).


Bottom of G37S manual transmission - no flat secure spot to hold and stabilize the transmission

Harbor Freight transmission jack with custom transmission base. It's all about the base.

Harbor Freight transmission jack with custom transmission base.