My 1986 325 (build 10/85) automatic has no flex-coupling in the driveshaft. The transmission has a 4-bolt output flange, and the driveshaft likewise, so it's not a case of being bolted together without a guibo, which takes a 3-bolt flange. I don't see a mention of this in Bentley, and realoem shows a guibo in the diagram but does not list it in the parts description. Could some past mechanic have substituted some other parts, or are 4-bolt flanges a known variation? thanks Rick McClinton