Rear Swing arm mount / chassis rot advice.

[davegsm82]

A little while ago I found a small hole in front of the passenger side swing arm mount, I opened out the hole to about 1.5" x 1" and stuck an endoscope camera and a bright light in there to see what was going on. Looks like water has gotten in the inspection hole in the arch and rotted some of the area on top of where the mount is welded to the sil.

The area around the mount is sound apart from at the bit at the front which I removed back to fresh steel and I've managed to remove the 'flaky-pastry' type corrosion directly on top of this mount.

The mount itself is absolutely sound, no corrosion at all. The welds all round are sound too as well as the chassis crossmember where it attaches at the side.

So I have to ask myself, is it worth burrowing through the floor in the van to get to this area when;
A) the only metal gone is not structural an was only on top of the flat area of the mounting bracket.
B) I can get perfect access through the hole I made and the one in the arch in order to use some rust treatment product and then some waxoyl or similar (then seal up that hole I opened up).

Thoughts?

[CovKid]

Latter although what you think is not structural doesn't match MOT specs. Its all about distance from structural areas when it comes to rust/rot and MOT failures. I'm not trying to dismiss your solution as its fine but you need to make absolutely sure no water can get in there again and that everything really is sound. You're the one driving it. If you're confident its sound, so be it

[davegsm82]

Cheers Covkid,

Yea I'm pretty sure that area is sound, I'll be doing more work on it this week as I have to replace the rear arch panel and a small section of the inner arch so I'll make sure my assessment is 100% correct before committing to any work here.

With regards to structural repairs, what is the MOT guideline on this? obviously work is permitted in this area but what is the final answer when it comes to welding etc? Surely they can't expect you to replace the entire sill/rail... surely... ?

Also, at the end of it all, if they prod and poke things and they don't crumble then I guess that's technically a pass, correct? if I put a 1x1.5" plate into the hole, butt-weld and stonechip it then that should be up to a pass?

Thanks for the advice.

Dave.