As part of modifying the subframe to suit the new engine (or more specifically, to suit the CV cups), one side of where the lower control arm pin bolts in has been removed so a new one has to be made.
I knew this was going to happen so before I cut the subframe up I made a small box to replicate the original position of the pin that goes through the control arm bushes. The two holes in the box were drilled to 1/2" to match the diameter of the pin and the box width ended up being 39.5mm, however because the bushes are squeezed slightly when the nut on the standard control arm pin is tightened, I increased the box width to ~41mm.
Instead of using a brand new (fully threaded) bolt through the control arm bushes, I wanted to use the original control arm pin because the main part of the pin is NOT threaded and fits snugly in the bushes. I just needed to shorten it so I used a grinder to carefully cut away the weld that was holding the centre washer in place, cut the pin in half and hammered the washer off.
Some 8mm plate was welded to the top section so that the main steel plate that will hold the pin would be vertical
and a piece of 6mm plate was cut (with a 1/2" hole drilled for the pin) and welded in place, using the box to locate the position of the drilled hole and the necessary width of the control arm bushes. You can also see the (cut) original pin and nut holding the plate in place.
Once I knew the exact length the pin had to be, I placed the thick washer over the pin and welded it on.
And just like on the original subframe, I trimmed a small arc off the washer and welded a small piece of plate to keep the pin in place while the nut is being tightened.
UPDATE : I have since abandoned the idea of using a modified control arm pin. While I was making the lower brace bars to run under the engine/gearbox, I inserted the inner CV cup and layshaft and found that while they are installed, I would not be able to insert the pin through the control arm mount (see pic below). If I ever had to replace the lower control arm bush, I would have to remove the driveshaft assembly just to remove the control arm pin, so I have drilled out the mount (left hand side of the pic below) and got a mate of mine to machine up a new pin on his lathe instead.
I knew this was going to happen so before I cut the subframe up I made a small box to replicate the original position of the pin that goes through the control arm bushes. The two holes in the box were drilled to 1/2" to match the diameter of the pin and the box width ended up being 39.5mm, however because the bushes are squeezed slightly when the nut on the standard control arm pin is tightened, I increased the box width to ~41mm.
Instead of using a brand new (fully threaded) bolt through the control arm bushes, I wanted to use the original control arm pin because the main part of the pin is NOT threaded and fits snugly in the bushes. I just needed to shorten it so I used a grinder to carefully cut away the weld that was holding the centre washer in place, cut the pin in half and hammered the washer off.
Some 8mm plate was welded to the top section so that the main steel plate that will hold the pin would be vertical
and a piece of 6mm plate was cut (with a 1/2" hole drilled for the pin) and welded in place, using the box to locate the position of the drilled hole and the necessary width of the control arm bushes. You can also see the (cut) original pin and nut holding the plate in place.
Once I knew the exact length the pin had to be, I placed the thick washer over the pin and welded it on.
And just like on the original subframe, I trimmed a small arc off the washer and welded a small piece of plate to keep the pin in place while the nut is being tightened.
UPDATE : I have since abandoned the idea of using a modified control arm pin. While I was making the lower brace bars to run under the engine/gearbox, I inserted the inner CV cup and layshaft and found that while they are installed, I would not be able to insert the pin through the control arm mount (see pic below). If I ever had to replace the lower control arm bush, I would have to remove the driveshaft assembly just to remove the control arm pin, so I have drilled out the mount (left hand side of the pic below) and got a mate of mine to machine up a new pin on his lathe instead.
Nice work there.
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