I too am an owner of a 698 (1st series which does not have a cueing control on the plinth or the bottom of the unit) the cueing problem you have is due to age, the old silicone, needs to be replaced, which can be a headache and a half.
The arm needs to be removed entirely from plinth and turned upside down, unscrew the round disc plate underneath. Once the screws are removed carefully pull the plate away, youll see a small copper lever, put that aside for now, very important for reassemble.
Now, unsnap the rubber and metal cueing platform (under the arm), with your finger push the piston of which you just unsnapped from the cueing platform. You will see the piston as its being pushed from the topside, pull out the piston. With a q-tip dampened with alcohol, clean the walls of the piston chamber and making sure around the top edge of the piston chamber, now clean the piston, pay attention to the stepped area (this area actually fits into the coil or piston chamber and can cause a seal if closed, (You dont want that).
Now you want to reassemble, first you need to have the silicone you plan to use. Add a dab on each side of the piston before you insert the piston back into the chamber, twist the piston so it will coat the entire chamber.
Reassemble the arm, that small copper piece, with the nub resting on the bottom of the piston, screw the bottom plate back on , just like you took it off., snap the metal and rubber piece into place.
Place arm back onto plinth plug it in and check the rate of speed for cueing, if not slow enough you need to add more silicone and if to slow you need to remove some.
Did i say headache????