C3 Transmission Swap - Grabbin' New Gears

The next step is to cut the tunnel hump. We used a $35 AmPro reciprocating air body saw to make the job very easy.

This is the Keisler tunnel cover.

We first need to place the cover down inside the tunnel to position it correctly in the new cut tunnel hole. We center the cover in the opening.

Next we use small C-clamps to lock the tunnel cover to the floorboard so it won't move.

We then raise the car up on the lift and drill out several holes through the new tunnel cover and through the floor board for the new boot trim ring. We use a 1/8" drill bit and will use a 1/8" rivet to anchor the cover.

We then lower the car, remove the C-clamps, take the tunnel cover out, run a small bead of 3M Body Sealant in the middle of the plate where it will seal to the underside of the tunnel. Then the cover is put back down through the tunnel hole and the drilled holes are lined up.

Now place the boot trim ring and the 1/8" spacer (placed on driver side of hole) on the tunnel cover and secure with multiple C-clamps. Make sure the boot trim ring, spacer and cover are lined up properly. Drill the 1/8" holes for the boot trim ring screws. You can now remove the clamps and boot trim ring for now.

Now place the boot trim ring and the 1/8" spacer (placed on driver side of hole) on the tunnel cover and secure with multiple C-clamps. Make sure the boot trim ring, spacer and cover are lined up properly. Drill the 1/8" holes for the boot trim ring screws. You can now remove the clamps and boot trim ring for now.

Now the tunnel work is complete for now. It's time to install the tranny.

Now raise the car back up. The first thing to do is to seam seal the tunnel cover from the bottom of the car and then you can paint to make the underside look clean. The next step is to dial in the bellhousing.

Here is the T45-RS ready for the install. You should have done all your preparatory steps that Keisler dictates in their install literature and the tranny should be ready to go at this point.

Lift the transmission assembly up (preferably on a tranny jack) to the back of the bellhousing and insert the input shaft into and through the clutch assembly. The lower left mounting bolt (arrow) is partially captured in front transmission case and requires an open end wrench. Make sure the back of the transmission is supported until the crossmember is installed.

This is the original crossmember with the new crossmember bracket and E-brake pulley assembly that Keisler manufactures in-house for this application.

This is the optional exhaust hanger bracket that also is used in conjunction with the crossmember for rear exit exhaust equipped cars. Our install did not use this bracket since our car had sidepipes.

Next, the crossmember is lifted into place.