The left hand sill structure actually looked quite solid, in fact along it’s length it didn’t have any rust holes at all. The only visible rust was in the area where the bottom edge of the front wing mounts. Despite the apparently good condition, I was going to replace it anyway as I had on hand a genuine replacement sill (part # 76413-K1330) and it’s the only way I could be sure of eliminating future rust issues. I started by chopping the main section of the sill away using an air chisel, leaving the spot-welded seams in place. Once off, the inside of the sill showed plenty of surface rust and and the front of the inner sill required exactly the same type of repair as I had done on the right hand side.
Having completed the right hand side of the car it’s time to tackle the rust on the other side. This is no doubt going to entail pretty much the same work as doing the right side so I’ll probably gloss over some of the details and just provide the pictures and note any differences in the work required. At first glance it seems that the inner wing and upper strengthener are maybe a little better than the previous side but this doesn’t make a lot of difference really as it’s the same amount of work to repair what rust is there. The sill isn’t as rusty but the left rear arch is considerably worse than the right, requiring the entire edge to be replaced all the way around. The inner sill areas by the rear cross-member mount is much worse too so there’ll be some fabrication needed there. I’ll be working my way along the car in the same manner as I did the first side so I start with the inner wing strengthener.
The final area to tackle on this side of the car is the front inner wing. Initial inspection only revealed rust in the most common area for these cars to go, the bottom of the strut tower just above the chassis leg, but once the underseal was scraped off from the under arch area there were definitely a few more suspicious looking areas. The bottom couple of inches of the inner wing panel overlaps the chassis rail on 710’s so that whole area is double skinned. Any moisture coming down the inner wing in the engine bay runs straight into this seam as it’s not sealed so rust can build up in there, rotting the section from the inside out. Not wishing to take any chances of future rust developing, I figured it was time to chop the lot out and replace it.