I have a '73 1800ES with ipd sway bars and 15" 205/R55 tires. While I don't mind generating the torque required to steer the front wheels, I'm not so sure the cross-member mounting bolts are designed to handle it. I recently heard moaning and creaking noises from the front end while cranking the steering wheel to park. On examination, I found the bolts connecting the front of the cross-member to the frame were slack enough to allow the frame to visibly twist from side to side.
Torquing down the bolts eliminated the symptoms, but the design of the mounts struck me as mechanically unsound. While the frame is double-bolted into a box joint at the rear of the cross-member, the front extension of the frame is just resting on a ledge on the front of the cross-member. The only thing that keeps the front of the frame and cross-member aligned is the tension on a single vertical bolt in an oversized hole. It seems to me that welding a short lip on the outside edge of the cross-member ledge would wedge the frame into the cross-member, bracing the frame against the shearing forces generated by hard cornering. Have any thoughts on this issue?
Lee Powell
lpowell@machinecode.com
David says: The majority of the front end steering and suspension was designed for very skinny bias-ply tires on 4" wide rims.
When your bolts loosened, did you lose or remove the shims that go between the crossmember and the box section?
The only problems we've encountered from extra cornering and braking forces generated through my driving and Hoosier 225/50/15 street TDs is more frequent replacement of tie rod ends and breaking upper A-arm bolts. The upper A-arm attachment bolts are now 1/2" AN where 7/16" grade 5 coarse-thread bolts used to reside.
Welding a lip on there would not hurt anything as long as it did not affect the alignment of any components. Some racers weld the cross-member to the body at this point. I have not done this with the 1800E we race. I have not seen any evidence of movement there with fresh grade 5 bolts torqued and locktited.
