Front Jacking Point Replacement (Part 1) - Removal

Or........"Man Versus Jacking Point"

or........."Square Pegs And Round Holes"?

Most people seem to assume that the odd, but convenient, oblong posts that sticks out of the chassis approximately below the ‘A’ posts are supports for jacking the car and for axle stands. If you’ve read my post of 15 February 2018, you’ll know that that while that’s not entirely wrong,  they are actually part of a more elegant solution: the  tube is intended to hold a ‘paddle’ (Citroen tool number 2505T) which then form the intended jacking pad.

Citroen jacking pad inserted in the jacking point

Being low down and just behind the front wheels, those oblong jacking points pick up a lot of spray and dirt and the tubes themselves are major rust traps: you often find cars with those tubes completely clogged with dried mud or, worse, wet mud.

Rusted jacking point (photo copyright: Colin Smith)

Very early on in my restoration, while my car was still languishing up at the barn, I was preparing to jack it up to remove the exhaust or something.  The jacking points looked a bit crusty and, as a preliminary  precaution I had a prod around with a screwdriver (like you do). To my alarm, it went through the top buttress of one of the oblong tube sections!

May 2015: Rusty jacking point....

Disaster! Firstly because it meant that the jacking point might collapse if I tried to use it. Secondly because it was clearly an MOT failure and would ned to be fixed before the car could go back on the road. At the time I had no welding equipment – not to mention a lack of welding skills (or confidence), so I’d either need to get the car to a garage or get a welder out to the car. Both sounded inconvenient and, although the need seemed a very long way off, I put the job on my ‘to do’ list.

Up Close: corroded and weakened.....

I'd gone as far as buying a repair panel from the Citromobile event back in 2015. The only problem with this replacement part is that the oblong tube part has the wrong dimensions and is too tight to comfortably take the 2505T paddles. My paddles shown signs of previously having been hammered in, but I think that's to do with dirty and clogged tubes, rather than an intended tight fit. I'd hate to hammer them in and not be able to remove them!

Fast forward several years and I have now acquired a welder and have made some use of it. In short I’m more confident with welding, even if I’m not exactly apprentice of the year. I’ve recently started the job of cleaning the engine bay ready to receive my rebuilt engine and, as that will involve some chassis painting, turned my thoughts back to a repair of that jacking point. 

I did some online research on removing spot welds and repairing using plug welds. It seemed to be the kind of thing that should be within my capabilities – especially if I had any serious intentions of getting around to replacing my door bottoms. Replacing a jacking point would be good practice. 

The procedure for replacing the jacking point (or to give it's proper title, the "front side member closing panel" and "front unit closing panel and body siderail") is covered by Operations D.741-7 and D.741-7a in manual 471. Now manual 471 is quite old - 1964 in fact - but the main components of the body changed little and so the repair techniques therein still apply.

Illustration from Manual 471

As well as the illustration, the manual includes step by step instructions. The replacement panel I'd bought was helpful for understanding how everything was fitted together. 

Repair panel. Can you see where it goes?

With the wing, door, suspension dust shield and mudflap removed, I could see that the rot was worse than I'd initially discovered and extended to the flat plate behind the jacking point. Again, it’s readily available as a replacement panel and so seems to be a fairly typical repair that might need doing on most cars.

Nice big holes......

I began to size-up how to do the job. I’d previously seen posts on Colin Smith’s blog where he had replaced his jacking point  (see HERE and HERE) and, more recently, had followed a thread on Aussiefrogs by Sven (aka'Bluedanube') that included some very handy photos - see post 147 in that thread. I invested in some additional tools. This was a tactical decision: they would give me something to blame if it all went horribly wrong!

I bought an ‘L’ shaped seam splitter (not cheap but already a firm favourite of mine) and some spot weld removal drills. 

New Toy: Seam Seperator

The principle behind removing a spot weld is to release only the small area of the front layer that is joined to the layer behind. You could try chiselling between the two, but this is very destructive and ends up tearing the back layer. You could mill out the welded portion of the front layer with a drill to completely grind away the welded spot, but the angle of the cutting face means that you are likely to be penetrating the back layer of metal before you fully penetrate and free-up the front layer.

I opted for a drill that cuts a ring around the weld to free-up the top layer of metal. A disc of top metal remains welded to the lower layer of metal. All you do then is carefully grind off that disc to give yourself a clean, flat surface to plug weld the replacement part on to. That’s the theory anyway. The drill also has a spring-loaded retractable tip to centre and guide the drill. 

Spotweld Removal Drill

The teeth are very sharp and, as the drills are made of hardened steel, are more brittle. I was warned that I should expect to lose some drill teeth along the way. The heads are reversible so can be used twice and the set I bought included six of these. With six double-ended drills the set seemed to represent value for money and should keep me going for a while. 

I needed to find the spot welds that were holding the rusty panel in place. I cleaned up the area with a scraper then a wire wheel and/ or cup on a drill. With the Schutz, paint and sealer removed, these revealed themselves as subtle circular indentations in the surface of the metal – maybe 5mm or 6mm across. I used a Sharpie pen to mark these. In some cases, the panel was rusted and pitted along the spotweld line and I couldn’t see exactly where the weld points were. I reasoned that these would become apparent as I began to release the panel. More on that later......

Cleaning up the spot welds

The idea is to use a centre-punch to mark the centre of the weld and to provide a ‘footing’ for the retractable drill guide. In reality, the teeth of the drill are so sharp and pointed that they ‘snag’ pretty easily as you drill, and the drill tip can dance across your work piece - which is how it loses some of it's teeth.

Broken Teeth......

Following a tip in a video I used a centre punch, but then followed this up drilling a 2.5mm hole right through the metal. In some cases you can simply deepen the centre-punch mark, but on thin sheet it's very difficult to go deep enough, but not go all the way through. Why 2.5mm? The hole is the same size as the diameter of the retractable drill tip so, instead of retracting, it passes through the work piece. That might sound odd, but it then acts as a far more stable guide for drilling. Secondly I also have some silver ‘Cleco’ fasteners. These are used to align panels for cutting, or to hold over-lapped panels together for welding.

'Cleco' fastener - a spring-loaded gripper

My silver ones have 2.5mm pins, so any holes used to remove welds could potentially be used to fit ‘Cleco’ fasteners and so realign new panels to old, for welding.

'Cleco' fastener in it's applicator tool

There is a third reason. I didn’t want the hole to be any bigger than it needed to be. You just need to be careful when drilling these small pilot hole that you don’t puncture anything that lies unseen behind – such as a hydraulic line, fuel pipe of electrical cable…….

With pilot holes drilled, the spot-weld removal drill worked like a charm, chewing through the steel sheet quite happily with a satisfying grinding noise. The trick of course is not to get carried-away and drill too deeply and to only release the top sheet from the bottom. That’s pretty tricky as you can’t tell where the top layer ends and the bottom starts. If you are lucky, the top layer ‘pops’ off once you have cut through it so you know you need to stop drilling.  

'Button' of spot weld left on the base panel

Alternatively, you might notice a burst of rust spray liberated from between the two layers. If so, stop drilling and inspect progress. 

I've gone too deep with this one....

Ideally and wherever possible, you cut your weld out of the panel that you are going to remove, leaving the ‘base’ panel behind in good condition. However, in some places the jacking panel is tucked and welded behind other chassis panels: meaning I needed to cut through the panels I wanted to keep, in order to release the rusty jacking panel I wanted to get rid of. Now, the vast majority of these spot-weld drills are 3/8” diameter. This doesn’t sound a lot, but leaves quite a big looking hole to be plug-welded.

I gradually worked my way around the edges of the jacking panel. With a few welds removed, I thought the rusty panel would magically loosen up and begin to move out. No such luck. Having been welded in place more than 50 years ago when the car was assembled, it was in no hurry to move. With some judicious use of my seam splitter I was able to get behind an edge and bend it forwards.  In this way (where the front panel resisted and folded) I found several spot welds that I hadn’t noticed before. I also found a second line of welds at the top that I didn’t expect to be holding the jacking panel – but which were……. I guess, given it’s job (supporting significant weight) the panel is welded in very securely.

Swiss Cheese. Note two rows of weld holes along the top

It also looked as though the spot welds that held the buttress over the top of the square tube, penetrated the buttress, the jacking panel beneath and then went into some as yet unseen folded edge on the chassis. In other words three layers. That didn’t correspond with the photos I had found when carrying out research, but decided to cut those welds out as well (effectively dismantling the jacking panel) – just in case. The problem with that was twofold. Firstly, the flanged edge on the drill tip limited how deep the drill would penetrate. I could barely cut through two layers of thick steel. Maybe that’s the idea? Secondly, and if there were three layers spot-welded together, I wasn’t sure how I would plug weld them back together. I’ll cross that bridge when I come to it.

I discovered I would definitely need to cross that bridge several times over: despite freeing up the lower perimeter of the plate, it still stubbornly refused to come free. I discovered ANOTHER, hidden, layer of welds along the top horizontal line. The only way I could get anywhere near these was to cut-through, then bend up the outer flange that I had previously cut through and wanted to keep. The job was getting messy. Even then, I couldn't easily get to the spots, so had to resort to using the seam splitter. I realised that this join, the one I was trying to separate, joined the quarter panel to the 'A' post and passenger compartment. Sure enough, from inside the car footwell, and with the carpet removed, I could see daylight - or at least work lamp light.

Daylight!

With a bit of collateral damage to the flange, the main panel was finally removed. At that point, the jacking peg was still attached by its bracing panel that was fixed to the back of the main plate. 

Nearly done.......but jacking peg still attached.

With far better access now, that was easily removed - as were the remains of the flat panel behind the jacking panel.

So what did I learn? Firstly that while the principles of removal are straightforward, this was quite involved. These panels were not intended to be easily removed. The panels of a car are assembled in a particular order with some parts welded on top of others and other joins. I was effectively 'un-assembling' as much as 'removing'. Not only in terms of the rusty panels I removed.......

Remains of the removed panels

.......but also in terms of the panels around the rusty panel. "Un-assembling" was quite destructive, or if you prefer 'disruptive' (to those other panels). As well as a lot of careful cleaning up and re-bending of flanges, putting in the replacement panels would take a little thought in terms of the welding order. 

Finally got there! But a bit of collateral damage..........

Secondly I found that the spot weld drill I chose could be just as destructive to other panels as a standard spot removal drill. In a couple of places I had drilled right through layers I wanted to keep - leaving them looking like Swiss cheese. 

On the plus side, I was very, pleased to find that the Waxoyl I had added to the sills in about 1995 had done it's job. Although the outer plate was rusty, inside the box section was well coated and rust-free. 

Box sections are rust-free

So what's next? I need to straighten out some of the bent flanges and fill a few holes and - in the case of the top horizontal flange the footwell - maybe even find a way to replace a section of flange. That might not be straightforward as I think it will mean welding in the footwell corner. Looking back at some of the reference photos I had found on Aussiefrogs, I can see that others had similarly had to bend back that outer flange and butcher the inner one. It's given me some consolation at least! I've also discovered that one of the DS parts sellers sells two different kinds of patch panels. It's not clear what makes one better than the other. It could be thickness of the steel, it could be accuracy of the pressing. It could be a bit of both. Who knows - maybe the peg will be the same size as the original and enable me to use those jacking paddles as intended.