Mounting plate mating surface gaps too great
The cold (literally ... ), hard light of day reveals the following ...
1) The mounting plates on the bumper section are around 10 mm thick, and seriously strongly welded onto the bumper from top to bottom, both sides.
2) The corresponding plates on the steel mounting bar are 6 mm plate, and are also seriously strongly welded onto the bar and chassis rail mounting plate, both sides.
3) There is a 'credibility gap' between the two plates of about 6-8 mms in total; i.e. about 3-4 mms on each side (I need to relieve the bolts and measure this more accurately ... ).
4) Tightening all six 12 mm HT bolts
very tightly is not sufficient to bend either of these plates into a proper mating surface!
5) The bumper bar part has to come off so that I can measure up and drill some 3-4 mm alloy bar or plate to make up the difference, otherwise I will never be able to get the bar to stay in position! It currently moves around relatively easily.
6) This will probably
only take a couple of hours, as the holes in the fish plates can be a few mms bigger in diameter than the existing bolts and bolt slots. Probably best to make them out of a piece of checker plate 3 mm aluminium I already have. This may allow a small amount of 'crush' that should stop the surfaces slipping over each other in use.
The good news is that I have managed to bend the upper/rear 'wings' of the bumper out slightly by use of substantial force with one foot braced against the tyres. This makes for a far neater fit between the mudguard and the top/rear of the SubaXtreme bumper.
I am yet to locate any suitable plasticised material for constructing the plates that marry the lower edges of the bar to the rest of the car to exclude dirt and crap generally. I may fabricate these out of some 2 mm aluminium sheet instead. They will not be held on with body clips, except to tie onto the existing mudguard liners ...
The parts involved are:
a) one for each side at the bottom of the new bumper, about 250 x 300 mm;
b) one across the front to fill the gap between the lower trailing edge of the bumper and the leading edge of the sump guard, about 1050 x 120 mm;
c) a 740 x 100 mm piece to anchor the top of the grill to the mounting points on the bonnet lock cross-member in front of the radiator.
d) one for each side of the grill to radiator space that have currently got a bit of floppy sponge rubber in them. These will be about 450 mm high by 150 mm deep each, with a further 20-30 mm as a right angle bend to bolt them on, roughly shaped to the inside surface of the new bumper, and bolted on to the car side uprights.
I don't recall seeing any of this stuff mentioned in the SubaXtreme video, or on their web site ...
.