To make a long story short, my veh hit a cinder block at 55mph and it did a number on the underside of my veh. Body shop had to replace the entire front sub-frame with a used one and a number of other components. The veh has been making a clanking/ clunk sound when hitting bumps or during slightly more aggressive starts from a stand still. I have dealt with this type of noise a lot through ym car years and my first instinct is loose subframe, control arm, or sway bar end link. The veh went to the shop twice and both times I have been told everything is tight. I wanted to be sure so I checked myself, and indeed everything is tight. At this point I am annoyed because it was not there before. I have a very close relationship with the shop, so they let me look into and do some research with them.

Since the repair 1 thing has changed on the car. There is a center brace that runs under the tranny across the tunnel that was damaged. it got replaced so no worries except that the new piece came with a big long bolt in it. the piece on my car did not have this. photos below






This bolt passes through the brace and touches the drive shaft frame. The dealer calls it a tranny mount, but it doesn't thread into anything. It just touches the frame, almost as if to align it. I removed the bolt and my noises have seemed to go away on the few tests drives I have done. This is good, but it has me a little concerned as this seems to support the entire center portion of the tranny. I bought the car used and this is my first RX8, so I have no idea what is supposed to be there or not. All I know is that it wasn't there on my original piece and the brand new dealer piece came with it.

Is anyone familiar with this item? Is it supposed to be there? If so why is it making noise? Something else missing?

Any help would be greatly appreciated. I race/track this veh a lot, so I want to make sure all mounts are correct.

 

Okay, that bolt should not be there, but it is used to align the PPF (power plant frame). Remove it, your PPF is hitting the bolt.

 

Look under trans removal/installation.

http://foxed.ca/rx7manual/2003mazdarx8/

The cross brace is threaded to accept this bolt so you can do the alignment. I actually need this bolt, can you send it to me, I lost mine and finding a fully threaded M12 x 1.25 that is long enough is actually not easy.

 

What they said.

you have a unicorn bolt. Very rare...

Did the noise go away when you took the bolt out? I think the measurement is 2" from the flat part of the PPF to the bottom of the brace. That is measurement A in the picture from 9K.

And, share they name of the shop that did the work. They should not have left it in there, but the fact that they had one, and knew how to use it, is a very good thing.