Help rehabbing a Seiko 6309

[hourtime]

reached the end of my rope.....I agreed to try and rekindle an old Seiko 5  with a 6309 movement from the 70's for a friend of my son's.  It's been problem after problem.   Had to source new (used but new to me) parts and still not there yet.  Lots of issues, dial pins missing, deal feet set screws glued or otherwise frozen in place, filthy and a non-runner.  Disassembled and cleaned.  I am an amateur and am unable to jewel the mainspring barrel pivots or the other gear train pivots which are metal.  That in mind, it is re-assembled and running, but with low amplitude but worse than that, entirely variable results on the timegrapher.  it's like a sine wave.....it gains time, then loses time, the amplitude also varies from the 120's to the 240's.  I am bamboozled as to the cause.  I thoroughly de-magnetized, and oiled to the best of my abilities, yet it still varies and I cannot regulate this beast at all.  Anyone have suggestions?

[gbyleveldt]

That sounds like drag in the gear train, probably because of an out of round pivot bearing or arbour bush - these are common issues on that movement. Have a real close look at all the pivot bearings on the train bridge (usually many of these aren’t jewelled). Might also be debris in one of the teeth of the train.
 

Unfortunately, unless this is a diver or otherwise sentimental, it’s the kinda thing that gets stripped for parts. You might need to find another movement as a source for parts if you really want to get it going.

Anyway, maybe take a pic of the TG plot?

[mikepilk]

It sounds like the movement has had a hard life.
I agree with@gbyleveldt, it might be better to find another movement to use for parts. There's plenty of these movements about - look on ebay for cheap Seiko 5's, or there's plenty of movements here https://speedtimerkollektion.com/shop/index.php

[Malocchio]

As mentioned, that wavy timegrapher trace sounds like a worn bush. Especially 4th wheel bush in the train bridge tends to go oval or irregular shape. This picture is from a 6105. I replaced it with a jewel from a 6119. Direct swap, no reaming needed. I have the Chinese Horia clone and it's a great bang for buck. Also there's often too much end shake in 4th wheel so that the wheel almost falls off.

Edited September 22, 2022 by Malocchio