The TR2 through TR6 models came with pressed steel wheels as standard equipment. They ranged in width from 4″ on the early cars to 6″ on later models, all of them 15″ diameter with four bolt holes in a 4 1/2″ diameter center. Unfortunately, over the years these wheels have shown a tendency to crack between the bolt holes, until the four holes become connected, with the obviously disastrous results.
The principal source of many troubles comes when vintage racers attempt to use the TR6 wheels for everything from 2’s to 6’s. First they try to move them outward with spacers about 1/4″ thick. However, at that point the standard 7/8″ very deep wheel stud, can no longer be used because they now don’t protrude far enough to come out through the end of the lug nuts, since the spacers arc taking up 1/4″ of the thread! In an effort to overcome this problem, a much smaller and thinner lug nut is substituted however, it is a fact that these nuts don’t have enough purchase on the wheel, and can pull right through under extreme conditions.
Now comes the street application. Over the years, our TR wheels, like any others go through a number of sudden, high stress maneuvers. Over a period of time this high-stress Hexing causes cracks in the center section around the bolt holes. A number of years ago I had accumulated about ten or twelve TR wheels and decided to have them tested for cracks. SEVEN of them turned out to have identifiable cracks in the centers!
These wheels can be made safer by cutting a 1/8″ thick steel plate to match the outside diameter of the bolt pad, drilling with the appropriate holes, and welding this to the back of the wheel. In addition it doesn’t hurt to weld the spider (the wheel center section) to the rim as well.
Unfortunately, for racing purposes, these are only “band-aids” and not cures. For street use a little money spent on magnafluxing and reinforcing the wheel is good insurance. Finally, always use the full size lug nuts and make sure they are tightened lo correct factory torque settings.
by Ken Gillanders