Volvo Front Floor Replacement - Part 1

My new floor pans have arrived (no news on the inner rear arches) and so I have cracked on with repairs to the front offside floor.  My plan was to simply remove the floor pan (carefully), clean up, then trim and drop in the new replacement section.

I should know by now that things never quite go to that smoothly and sure enough after cutting away the floor I discovered a small hole in the inner sill, where the outrigger joins.  A few prods later and this small hole had developed into a significant issue. The outrigger itself was also looking like it needed attention and so there was no nothing else for it, it was going to have to come off. 

I briefly considered buying a new outrigger and if I had uncovered this before I ordered the floor pans, I might well have done so. The corrosion was not extensive however  and I was confident that I could repair it. I am also conscious that cost are getting out of hand and I need to save where I can. 

I removed the outrigger by carefully drilling out the spot welds and put it to one side. I thought it would be better to sort out the sill first, then offer up and make the new piece for the outrigger to achieve a ‘perfect’ fit. 

Creating the inner sill repair itself proved relatively straight forward as it is simply a straight, flat section. The complication concerned the jacking point which is attached to the inner sill. Before I removed the corroded area I was at pains to precisely measure and mark up the jacking point position. I also took a number of photographs and then I made a paper pattern.

It was vitally important that the jacking point should be refitted in exactly the same place as not only does it line up with a reinforced plate inside the sill, it also needs to align with a recess in the edge of the floor pan. Once I was happy that I had enough data I cut out the damaged section and then on the bench removed the jacking point as I was going to reuse it. 

Inside the sill there was some surface corrosion which I cleaned up and treated.  I also welded in a small plate for additional strength as I thought that the steel was a little thin in places. This area was then painted and seam sealed inside. I made my new section from 16gauge to match the original, achieving a good fit with an excess at the front edge which I would be able to trim off later.

The jacking plate has two predrilled holes through which it can be plug welded to the sill but these on there own would not be anything like strong enough. I performed a test fit and marked the jacking plate position. I then took everything back to the bench and drilled a series of holes through the repair piece to allow me to plug weld from what would be the inside, reproducing the original welding.

I then did a final test fit and plug welded the jacking plate to the repair section through one of the predrilled holes before once again returning to the bench to complete the welding. 

The new floor pan is a quality pressing and as it turned out an excellent fit. However, it comes with fair amount of excess and requires trimming before it can even be offered up. I took measurements using near side as reference and marked up my initial cut lines to the transmission tunnel edge. I then removed the excess using my air nibbler. 

The new floor extends into the rear floor pan area but I had already decided that I would only cut back to just in front of the centre box section. The metal here was good and removing it seemed unnecessary and additional faff. The exception to to this was the area between the handbrake and the sill. There was some corrosion here which on investigation extended back into the rear pan. More work then, fabricating an awkward shaped repair. 

Next I switched my attention back to the outrigger. I cut out the rotten metal at the sill end, then clamped the remains back into position, using the remains of the drilled spot welds as reference. From this point I was able to make a card template, cut and fold a repair, again from 16g, then tack it on knowing then it would be a good fit. I then unclamped and completed the welding on the bench. 

I test fitted the resurrected outrigger with the new floor pan and overall everything was fitting together well (I did spend quite a long time making minor adjustments and trims to get things bang on). Once I was happy, I welded the outrigger back onto the car. 

Marking up and drill the holes for plug welding the floor was a little tricky working out the position of the centre rails. I applied tape and marked up from underneath the car. I then cleaned up and painted the underside of the new floor. I also took the opportunity to paint the inside of the chassis sections with a coat of Hammerite, for a bit of added protection. 

I offered it up and with a minimum of tweaking it was ready to weld in. I had some difficulty with the welding itself as it was not possible to clamp the central areas. I had to resort to a combination of weights and brute force to get the surfaces to meet.

This worked out ok with the welds from above, but I hit a similar problem joining to the inner sill. Apart from the difficulty of welding from underneath, I couldn't apply any direct clamping pressure to the sill as it would distort the outer sill panel. In the end I made these wooden spacers which allowed the clamps to press on the sill seems, top and bottom.

I cleaned up the completed welds with an 80 grit flap disc on the angle grinder and gave it a couple of cuts of primer. 

All done. This has been a long job and it has taken me several weeks to complete (not helped by 2 weeks of jury service and family commitments.) The next phase could take even longer as I fully expect the rear arches to be... lets say 'awkward'. That's assuming those inner arch repair sections ever arrive...

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