As I worked on this family, I discovered two families I hadn't found in the 1940 census. Both families had been in the Detroit area in 1930, and had probably been there in 1940. I tried various spellings of "Kaechle" and even tried searching for "Raechle," but I couldn't find either family.
So, I decided to try a "trick" that has sometimes worked in the past. I looked at a neighbor from the 1930 census, and then found them in the 1940 census. In BOTH cases, it worked immediately. I found both families in 1940!
Here's one of the examples:
|1930 Detroit Census - Charles Kaechle highlighted yellow - Joseph Neigebauer is 3 families above Charles|
Charles Kaechle (age 50) lived with his wife and mother at 3013 Gladwin Avenue, Detroit, Michigan in 1930. He couldn't be located in 1940 using the usual search methods. So, I picked a neighbor with a fairly unusual name, Joseph Neigebauer, and searched for him in the 1940 Detroit census.
|1940 Detroit Census - Joseph Neigebauer highlighed yellow - Charles Kaechle is 4 families below Joseph|
When I clicked on the image for Joseph Neigebauer's 1940 census record, I scrolled down a few names and saw my Charles Kaechle! It even looked spelled correctly to me. When I looked at the index to see how the name had been transcribed it listed him as Charles Jaeckle. The initial "K" hadn't been written very clearly and been transcribed as a "J," and the "h" was misread as a "k." So, the name was transcribed as Jaeckle instead of Kaechle.
This method will only work if your family didn't move between the two census recordings. Also, if you don't find your family the first time, try a few more neighbor's names. It also helps to use unusual names and people who owned, rather than rented, their homes.
If you've not tried this method, give it a try! Let me know if you find a family you hadn't been able to find using the "usual" research methods.