Juke Box thinks Im Playing 33 1/3 records instead of 45's

[crabbylewis]

I have a 1975 Rock-Ola 460 juke box that plays both 45 and 33 1/3 R.P.M. 7” records. Sometimes when a 45 is placed on the turntable, the 3 red center guides on the turntable go down (the box thinks it is a 33 1/3 record) and the 45 record then wabbles on the turntable. Does anyone know what triggers the 3 red center guides to go down or recess like it thinks it is a 33 1/3 record to be played. I do not play any 33 1/3 records so I was wondering the cause of this issue. Is there an adjustment or switch to turn off the 33 1/3 record play? I have a manual but I do not see any reference to my issue. Thanks

[johndaniels]

Not sure if it's related to your issue (probably not if the unit is deliberately moving), but I had an issue with a 445 I'm trying to restore for a friend. In that case the cause was the three rubber mounting grommets for the turntable motor which had perished and allowed the motor to drop such that the idler wheel was often in contact with the smaller 33 1/3 rpm part of the motor spindle rather than the larger 45 rpm part. New grommets fixed that.

[Hildegard]

Do the 45s which make the three guides go down have the large or a small center hole?
Hole size "decides" whether they have to do down for 33-1/3 rpm or not:
Small hole: Center guides gp down = 33-1/3 rpm
Large hole: Center guides stay up = 45 rpm

[crabbylewis]

The 45's have the larger center hole size.  

[Hildegard]

So it's not an issue of "wrong" records.
Did you check the three TT grommets like johndaniels mentioned? They need to be undamaged, not squeezed or brittle or uneven etc.