|The MGA With An Attitude
Mounting the REAR BUMPER, MGA -- BP-104
At 06:44 PM 11/23/04 -0500, Fred Stankovich wrote:
>"These are new spring steel brackets and bumpers. Same form as my old brackets, but the rear bumper seems to fit too close to the body."
There is supposed to be one thick steel washer between face bar and the spring bracket in four places. If you just bolt the spring bracket to the face bar first, you should easily be able to get an end wrench in from the bottom to secure the large nut on the forged bracket. If the wrench won't fit between the face bar and the bracket (from the bottom), then the bracket is too flat.
Starting with MK-II car 102381 in July 1961, a pair of spacer tubes were added between the spring brackets and the shoulder on forged brackets to put the bumper slightly farther from the body. The official reason was to prevent the number plate bracket from hitting the body with a minor impact on the bumper from the rear. But that assumes you have the correct mounting hardware for the number plate bracket, including the rubber isolator grommets, which are missing from most cars (even concours cars). Check the Rear Bumper page in the Moss catalog and see where the number plate bracket fits in that assembly. Those two bolts in the center are pretty long.
The rubber grommets for the number plate bracket do serve a useful function (aside from allowing the bracket to stand up straight). They are vibration isolators. Without those in place, the number plate bracket I bought new for the restoration ended up with large stress cracks by about 100,000 miles. The vibration noise was driving me nuts until I figured out what it was, and by that time the bracket was cracked so bad it was nearly falling off the car, and I had to buy another one. I don't think the rubber grommets were really intended to protect the bracket. I believe they are intended to protect the number plate lamp assembly and the small light bulbs from excess vibration..
Additionally you may notice that the spring brackets have slotted end holes. This is not just for easy alignment during assembly. When the face bar takes an impact and is pushed toward the body, the spring brackets are sprung flatter, making them expand a little endwise. The rubber mounts on the center bolts provide enough give to allow the spring bracket to move endwise slightly at the moment of impact, lessening the likelihood of deforming the face bar.