It has been called to our attention that trouble is being experienced with the lower fork connecting link bolt breaking on the model 641 machines, both solo and Dispatch Tow.
In checking on this, we have found the cause of this trouble due to the steering damper assembly. It has been found that the steering damper stop, part No. 38813, and the steering damper, part No. 40197, has been binding on the fork bolt.
When this condition exists, the steering damper stop and post are drawn tight against the fork bolt by tightening of the steering damper rod, this will bind the fork bolt in the crown holding it fast. This bolt should work freely in the fork crown at all times. By holding this bolt fast in the crown, the leverage of the fork links will produce a twisting load which will break the bolt.
This condition is due to the steering damper stop seat being counterbored too deeply in the fork crown. If the parts are binding on the fork bolt, this can be detected by visual inspection and correction should be made immediately.
To correct this condition, remove the steering damper assembly and turn the steering damper stop unside down so that the greatest distance between the fork bolt hole and outside surface of this stop is installed at the top. It will also be necessary to install a spacer washer, part No. 22B20 on the steering damper post between the post damper flange and the bottom damper plate, part No. 38810.
By making this change, there should be ample clearance around the fork bolt regardless of the tension on the steering damper to allow the fork bolt to work freely in the fork crown assembly, thereby preventing breakage.
INDIAN MOTOCYCLE COMPANY
C. E. Raymond