I am changing a coupler right now on a 115 for that same issue. The 115 coupler is different from the 123 in design, but it sounded exactly like a bearing in the column. I think because the noise traveled up the shaft.
The coupler can be checked visually. Its no rabbit hole, just needs two eyes and a partner to work the wheel while you look.

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1985 300 TD 448K
1984 300 TD 278K

1983 240D euro 240k
1994 f-250 idi turbo 330K
1986 f-350 IDI
1987 F-350 IDI

1985 JD 1050 4wd
1965 IH 3660