Relative to the above points -Clifford Pope wrote: ↑Mon Oct 19, 2020 6:34 amI fitted one to an early Mark 1 once. Three observations:
1) Test the angle iron against to bodywork carefully, and adjust the curvature if necessary to ensure that there is a clear gap all the way across.
2) Fitting the angle iron behind the bumper inevitably moves the whole bumper assembly backwards. I found problems fitting the side bumpers because the holes didn't align up. I can't now remember the solution - probably enlarging the holes into slots.
3) The attachment to the boot floor is not going to provide much actual towing strength - it's only a thin panel. I think the purpose is really to counteract any tendency for the rear angle iron to twist.
A Mk1 towbar, depending on make, visually looks similar to the Mk2, but the holes for the rear angle iron are in a slightly different position (the distance between them is different - approx. 1/2") so if buying second-hand ensure it is actually for a Mk2 saloon. Hence the reason why a Mk2 saloon bumper centre section is different from a Mk2 estate (a Mk1 back end). Also the support brackets can be different depending whether it is an early or late Mk1 towbar.
If you re- use the original Triumph reinforced rubber bumper washers between the towbar angle iron and bodywork, then the bolts into the corner pieces should reassemble comfortably. If you use new but remanufactured ones that are now available, unfortunately, the ones I bought were thicker than the originals, which made assembly more difficult. I ended up removing them and fitting good used originals.
Agreed - the brackets that go from the drop plate to the boot floor / base of the spare wheel well are purely to reduce any twisting motion when loaded; the rear mounting bolts provide the majority of the strength of the towbar, which is why I would always use high tensile steel bolts whether bolting it in the original manner or reversing the bolts so the heads are fitted from the rear. The spreader bar mounted in the boot where the support brackets mount to the floor or spare wheel well is important too - some just sit flat on the boot floor whilst some are purely straight angle iron and have additional bolts to go through the inner boot reinforcing panel, but I have never seen the benefit of this as it invariably distorts this inner panel when fitted. Although not visable with the trim replaced, I don't think it is necessary and personally wouldn't do it.