I got a little distracted this week. I finished painting the diff, bought and painted a new top retaining plate along with a couple of new studs and then replaced the bushes in the rear radius arms before painting them too.
Now to start the chassis. First job was to get rid of the oil, dirt and surface rust. I thought of taking it to a sandblaster, but in the end I used a tried and trusted method – wire bush and elbow grease. With a wire brush attached to a hand drill I managed a reasonably thorough albeit dirty job. A couple of passes each side was enough followed by a rub down with degreaser. My final task was to cover the exposed top surfaces with rust converter and then leave for a few days to cure. I used Rustbuster FE-123 after very pleasing results on the earlier Stag restoration.
Next was to remove the rusty bits – namely both front outriggers and both side rails. Cutting the sections away from the good chassis was a fairly straight forward task with an angle grinder. What really took the time and patience was the removal of the previous welds in order to get the chassis back to it’s original dimensions. Under the welded ends of the front outriggers I found a couple of rust holes. These I carefully removed and replaced with some fresh steel of the same thickness as the chassis. I am not a professional welder but I thought the end result was robust and reasonably neat. I also needed some slight repairs to the centre outriggers.
I bought new heavy-duty replacements from Chic Doig in Perth. These slotted into place without much fuss. Before I could secure them in place however, I needed to make sure that they were in the right place for the front tub to drop onto. Unlike the rear tub, the front tub has close clearance fixing points. In effect this means that once the front is bolted to the chassis the rest of the is aligned to it.
These close clearance fixing points are at the centre of the front outrigger, the first and second holes through the side rails and the 3 fixing holes in the centre outriggers. On the right hand side (drivers side) I managed to get bolts through all of the close clearance fixing holes. This is easy I thought. With these in place I began on the left hand side. The fixing holes along the side rail seemed ok, but the centre front outrigger and the 3 holes in the centre outrigger were not even close. A full centimetre of more a drift of where they needed to be.
After careful inspection I noticed that the front floor to siderail backets are in slightly different places on the left and right sides. Roughly 7cm from the front on one side and 6cm on the other. That doesn’t seem right. Let me try and find some schematics.
Couldn’t find anything that included the dimensions and detailed location of the brackets on the underside of the bulkhead. So I’m just going to have to line things up as best I can.
I have managed to deduce from the car workshop manuals that the chassis crossmember beneath the engine is the datum point for all of the car schematics, so I figure that the bulkhead must be precisely parallel to the chassis cross member. The schematic also defines the chassis side rails as being parallel and therefore equidistant apart along their length. So I have positioned the bulkhead precisely parallel and put some temporary bolts through the first two crush tubes in the chassis siderails and the bulkhead fixing brackets. I can now see the front tub sitting properly on the chassis even though the brackets are not the same distance from the front of the bulkhead.
With the bulkhead in what seems like the correct position, I can see two problems I will need to fix:
- The two new front outriggers don’t fit properly. The problem is the same on both sides which makes me think it is an issue with the part. Perhaps there were slight differences across the model years and model variants and this is a generic part. Removing a little steel will solve this problem.
2. The left hand middle outrigger has been fitted at an angle. It should be at right angles to the chassis side rails but it is not close. As a result the 3 fixing points no longer align down the centre of the chassis rail. I may need to replace the outrigger.
