Project FD RX7 Restomod: Part 8 – Trans and Diff Mount

FD RX7 Rear Diff MountFirst we had to jack the car up to remove the PPF.

FD RX7 rear diff power plant frame PPFThe PPF bolts to the rear differential with these 4 studs.

FD RX7 front transmission mount power plant frame PPFThe front of the PPF connects to the transmission with 4 more studs.  There is an aluminum crossmember just under the transmission that ties the center of the chassis together for increased rigidity.

FD RX7 exhaust removed transmissionAfter dropping the exhaust, we were ready to remove the PPF.

FD RX7 removing the power plant frame PPF frontWe removed the 4 nuts from the front and rear of the PPF and it dropped out of the way.

5 comments

  1. Good writeup guys! Is the FD PPF really that heavy? I only have experience with the NA/NB Miata PPF which is a very light aluminum piece. Maybe only 5-10lbs. Is the FD one steel instead?

  2. I’m completely unfamiliar with Mazda’s ppf, so apologies if this is a dumb question. The ppf looks like it provides a bit of longitudinal stiffness that isn’t replaced with the new parts. Is there a risk of increasing the stress at some of the subframe connection points as a result?

    Love the project regardless – thanks.

    1. No worries at all, thanks for the feedback. The purpose of the PPF is to turn the entire drivetrain from the engine to the differential into one solid unit. So the entire drivetrain hangs off of the two engine mounts and the two differential mounts. The new setup changes this to a more traditional layout where the transmission is supported by a (new) bushing and the front of the differential is supported by a (new) bushing. Each additional bushing triangulates the engine/trans and the diff to provide longitudinal support and stiffness.

Leave a Reply

Your email address will not be published. Required fields are marked *

*
*