Volvo Repair: telescoping radio antenna, metal antenna, radio antenna

Question
Hi Regis,
I replaced the radio antenna on my '91 740 Volvo by removing the unit & reserviced it (greased)while removing a piece of the old motor line.
It retracks to the stored position & the antenna motor shuts off after a few seconds, OK.
Telescoping to the up position is the problem. What stops the antenna at the correct up position? The up operation ejects the telescoped antenna beyond the end of the metal antenna tube, showing about 2-3" of the "toothed" motor line. Also I noted that there is no ground wire from the relay. Is there a detailed diagram of the unit anywhere? The OEM antenna replacement kit was rather lean with the details. Thanks

Answer
whn the mast is out there is a brass looking piece on the bottom a ring around the base of the mast.then on top of this is a thin metal sleeve that fits over the mast but will not let the mast come out pst the brass ring on the bottom of the mast.you will need a new mast to get this piece.