Some 70's MITCHELL 308/408 whitch are sold as "used" have problems on their bearings. The ex-owner's disassembling the roter is the cause. Please check your reel. I show how to adjust bearing.
1 Remove the side cover
Remove the screw by a coin.
2 Remobe the main shaft.
Remove the main shaft.
3 Remove the roter.
It is defferent from the presence spinning reels. Remove the small set
pin screw. Then you can remove rotor.
4 Remove the rotor nut.
Remove the rotor nut.
5 Remove the pinion bearing ass'y.
Unscrew the pinion bearing ass'y. This point is defferent from the presence reels too. Some owner do not know. Such owner's reel ofen has the problem shown 6.
6 The looseness of adjust nut.
The problem is this. The ex-owner removed the rotor nut. But he does not know the construction. He could not remove the rotor. So, he reassembled.
In this case, a clearance is made between the rotor and adujust nut(pointed on picture). Then the adjust nut looses. It causes the damage of gears.
Before disassemble, remember the direction of bearing unit.
7 Parts.
Put the parts in the order.
8 Reassemble.
Reassemble the parts after clearning. Do not mix the balls of front and
rear. The balls are 17 pcs per a race. I use Shimano's spinning grease
sold in Japan.
9 Fix the adjust nut.
Asemble by the procedure contrary to disassembly.
10 check the looseness and rotation.
Check the rotation.
11 The 80's models.
The 80's models are locked the rotor and pinion. You had not better disassmble. The 90's models are same.