Outer sill top edge... cut off to replace sill?

[RobFrost]

Supposing i replace the outer sill, what's the best way of removing the outer sill here at the top edge? There's some pitting in the sill around the trim drill holes and a hole above the kidney bowl. One solution is to replace the sill, which is probably easier than localised repairs.

With the welds being so close to the edge I can see drilling them out will be messy. Do people cut the whole edge off and weld a new edge to the car before fitting thr new sill? Or drill them out and repair the edge?

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[SeanP]

Normally just drill out the spot welds and brake the remaining weld with a panel splitting chisel. Once off straighten the edge out with a hammer and dolly. You then asses the state of everything.
If the outer sill has rot then you can pretty much assume that the middle sill has rust including the jacking point strengthening piece, around the A pillar and kidney bowl

Barry Carter did an excellent write up on replacing sills do a search for sill replacement.
Its a big job but doable with time and patience

Here is a picture of a trial fit of the sheet metal I replaced on the passenger side! Did the same for the drivers side.

BFEB1ECC-B5CB-4861-9826-A0DFC4FCAC01 by Sean Plumpton, on Flickr

E9CA5A66-81E2-4E8A-82F9-7B748FC52904 by Sean Plumpton, on Flickr

Hope that helps
Sean

[Gary71]

As Sean said, try and remove it gently as it’s the top one of three layers. Agree that if the outer is bad enough to warrant replacement then the middle sill (in Sean’s pic) and jacking point will need some love.

I took out the middle sill as well on my car, and by that point the flange was shot, so I made a full length strip and welded it to the inner. A little oversize so it could be ground flat once the new middle and inner are in place.

[deano]

I removed both of my outer sills. The second one went better than the first, and I learned a few important lessons.

As the other chap said, its quite a big job, but more time-consuming than difficult.

I think you are talking about tackling the spot welds inside the door seal channel. If so, here is my take on the best way to do it, while making sure that everything under the outer sill and the seal channel remains undamaged: slice along the top step, as far into the door seal channel as possible (take care not to cut further than the outer sill itself, avoiding cutting into the inner sill). Cut around the A-post, about 40 mm away to preserve the bracket that the sill sits on. Same on the kidney bowl side, and around the jacking point, leave some on so you can see how it is joined. Slice along the bottom of the sill where it meets the floor flange, again making sure that you only cut through the outer sill, to avoid cutting into the adjacent inner sill (I learned this the hard way). Remove the sill and you now have much better access to the spot welds and can decide how best to remove them. I think I used my B&D belt sander with 10 mm wide belt to work through the spot welds and wiggled the flange loose as I moved along the sill - just takes a few seconds per weld (40,60 grit) and much more productive than spot bits. When its not possible to get the belt sander in, I use a spot bit, or carbide rotary burr on the Dremel.

It is difficult to get in with an inspection camera to see the state of the inners unless you are removing the kidneys (and rear quarter). My inners were solid (and original). I ruined one of them when removing the first outer sill.

Sounds like yours might be a candidate for leaving it alone. I wish I had - I only really needed kidney bowls and one jack tube, but ended up with all new after hundreds of hours and thousands of £

Best of luck!

[Gary71]

This ^ is a good strategy for preservation! I wasn't too fussed so went in hard

[RobFrost]

Thanks for the advice guys. I can see the jacking reinforcement is intact, albeit a bit brown. The vertical part of the kidney bowl looks fine, but the horizontal part is toast.

The corrosion in the outer sill is only pitting around the drill holes for the trim, but being the full length of the sill I think it'll be easier to replace the whole sill.

These are the welds I'm talking about. I hadn't realised three layers meet here, although it's kinda obvious now you say it. Sorry, I thought I posted this on the original post.



If you're saying it's three layers then I don't want to drill through from the top, do I? As to do that, I would separate the intermediate sill from the inner one, correct?

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[deano]

Just a small clarification, the three layers only exist in the vertical part of the door seal flange - see my sketch below.

The inner sill stops just before the jack socket reinforcement, then the inner rear quarter starts. A similar 3-layer setup then exists with inner rear quarter on the inside, the outer sill in the centre, and the B-post (door lock panel) on the outside

I should have mentioned before, the overlap between the outer sill and the B-post is perhaps the trickiest most time-consuming part of all - just as the inner sill is sandwiched, after the inner sill ends, the outer sill then becomes sandwiched between the bottom of the B-post and inner rear quarter, as you can see from my photo. The spot welds for the kidney too are tucked under the B-post, as per last photo, and the rear end of the outer sill sits on the forward end of the kidney (not shown) so the bottom of the B-post has to be removed to fit new kidney.

- my new rear quarters (with B-post already attached) and outer sills and kidneys, all from Porsche, needed a lot of work to make them fit together (splice and re-weld).

If yours only has a bit of pitting, it might well be worth cutting a small window in the outer sill, under the rear quarter, to assess the damage, before entering into a full replacement job... IMHO

[RobFrost]

Just a small clarification, the three layers only exist in the vertical part of the door seal flange - see my sketch below.

The inner sill stops just before the jack socket reinforcement, then the inner rear quarter starts. A similar 3-layer setup then exists with inner rear quarter on the inside, the outer sill in the centre, and the B-post (door lock panel) on the outside

Sill detail.jpg

I should have mentioned before, the overlap between the outer sill and the B-post is perhaps the trickiest most time-consuming part of all - just as the inner sill is sandwiched, after the inner sill ends, the outer sill then becomes sandwiched between the bottom of the B-post and inner rear quarter, as you can see from my photo. The spot welds for the kidney too are tucked under the B-post, as per last photo, and the rear end of the outer sill sits on the forward end of the kidney (not shown) so the bottom of the B-post has to be removed to fit new kidney.

OuterSill detail.jpg

UnderOuterSill detail.jpg

- my new rear quarters (with B-post already attached) and outer sills and kidneys, all from Porsche, needed a lot of work to make them fit together (splice and re-weld).

If yours only has a bit of pitting, it might well be worth cutting a small window in the outer sill, under the rear quarter, to assess the damage, before entering into a full replacement job... IMHO

Thanks for the advice. Another reason for removing the sill would be to repair the kidney bowl. Aside from the rust around the trim screws, there's a hole at the foot of the b pillar from the rain that runs down it inside the door, which is the main problem with the sill. Maybe I'll cut it open as you say and assess. It could be worse than it looks

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[sladey]

Brace it properly first. You don’t want it moving

[RobFrost]

Brace it properly first. You don’t want it moving

If I remember correctly in a conversation a year or two ago Barry said as long as there's plenty of inner and intermediate sill, it's sufficient to simply jack a bit of the engine weight up to replace an outer sill. But bracing might be a good precaution all the same.

[911hillclimber]

I did both sides of my 73T in 1989 when Barry was at Primary school, not sure if the internet was invented even either.

The difficulty was aligning the out in the end along that top flange but i had Dansk replacement sills...

The top flange was good but the previous owner had already replaced the sill with ford Cortina items(!), the label was still inside the sill pressing, thus the top of the sill was well roached, but it all worked out.

The inner sill (original) was rusted at the floor and the floor needed cutting back 100mm to find thick original steel. The chase back to good steel was dramatic Rob.
The kidney bowls were gone and the metal behind them, and at first I thought the area was ok.

Engine was out so i had the car on axle stands at the rear torsion bar mounts and 2 stands under the steering rack cross member fixing points section, all leveled by spirit level.
No bracing, one side at a time, shell (coup) stayed true.

911 sills are hard, MGB sills are far harder having done 2 before my 911!