If you have your manual 2-31 has a good exploded view of the assembly. Might be your gland bolts have loosened.
http://www.arcade-museum.com/manuals/manuals_pinball.php Link to manuals if you don't have one.

Look at my post last month on the forum....
TAF: bookcase assembly adjustment / resolved
May just be the same thing.

image.jpg
Maybe this will help

Ok so check part # 42 is tight under the playfield with no space between it and the washer / shaft and not missing or in your cabinet.
Also verify that part # 38 is also tight.
These two screws tighten everything and are opposing screws and keep everything in between nice and snug.
Screw # 38 is internal of the bookcase . To access #38 remove two screws on top of bookcase. When I opened mine it had completely backed out and was laying inside top of bookcase .
Once you have both screws #42 and #38 nice and tight you can unscrew part #37 with your fingers, just back it off a quarter inch or so which will now allow you to adjust the height of the bookcase assembly by turning part # 33 right for up and left for down , you may have to do it a couple times before you get it just right, but each time you adjust height you will need to retighten #37 to hold in place. Once you have the correct position just give #37 a good hard finger tight turn .
Hope that makes sense,

// Error: Image 279290 not found //

There also should be some shims (if needed) that go under the brackets that mount the bookcase. Maybe a screw pulled out or loosened enough and dropped the shim out?

Kinda hard to see but shim is under the one screw here on mine:

Bookcase shim

You need to use one or more shims to get the bookcase disc level with the rest of the playfield (in the down position of course) and then use the central screw to make it even with the playfield.

Shim - bookcase
#01-10759

Bally ADDAMS FAMILY and ADDAMS FAMILY GOLD bookcase metal shim.

Reference:
01-10759

Weight: 0.19 oz

http://www.marcospecialties.com/pinball-parts/01-10759

RussMyers

So what are the proper steps to leveling the bookcase, and then setting the correct height?

I was able to:

1. tighten up 38+42
2. loosen 37 and tighten 33
3. the result is the blue plastic is poorly pitched by about 5°. Correct on the downslope side, and incorrect on the backbox side.

-mof

201507_TAF-bookcase.jpg

See the prior post. You need the shims to get the bookcase base parallel with the play field then adjust the height.

So is it:

1. Set level and pitch via: shims only
2. adjust 37 and 33 to get the height adjusted correctly

-mof

Came out GREAT !
TY for the suggestions.
I removed a shim, and added a few shims of my own, and got it nearly perfectly level, and tightened it all up. Plays better than I've seen in the last 3 years (the bookcase was ALWAYS loose)
-mof

@golfingdad1...I got my first TAF last week and your advice on the bookcase fixed my only problem with the machine. Just wanted to say thanks!