Mech pickup arm cradle frame delayed shifting

[andylevine]

Every now and again when switching from the A side to the B side, the pickup cradle doesn't shift smoothly. This only seems to happen going from A->B, not the other way.  It seems to delay, I hear a few Ka-Chunks (thumps??) sometime less or more, then finally it shifts and everything returns to normal. It does not appear to even be attempting to move.  Its hard to see the cradle actuator or the shift cam through the record rack, so I don't know if it's the drive crank not settling in the cam or something else.  The one time I DID get a glance while it was happening, it appeared the cam was not moving at all, which leads me to believe this could be clutch related.  I KNOW the clutch is well lubricated, but it is certainly possible I missed something else while lubing after the cleaning. Detent actuator and lever definitely oiled.  Could this be a worn clutch member??  If so, what are the remedies?

All thoughts appreciated.

Thanks
Andy

[robnyc]

Andy, does it bring the record up and play it -even if wrong side? If so it isn't clutch. Make sure the rail on the cradle is oiled.

In -most- cases clutch member wear appears in the lower notches since these take the hit when the mech goes into scan. that shows up as bucking and sometimes stopping & just spinning (severe cases). If the clutch yoke binds and doesn't shift up-down easily it can cause the mech to just stop during record lift or when the clamp is retracted. BTW: Is the cam roller at the left outside of the mech there and working? That is important in evening out the load profiles on the main cam.

Also, looking at this pic: www.flickr.com/photos/90641375@N06/24865555337/ When the tonearm is in rest position, make sure there is a little looseness between the collar bolts and the vane at the upper left and also the one down center (ignore the red lines).

If either one is too tightly coupled it will set up a bind that inhibits cradle shifting.

Hopefully, Ron will think of something I omitted.

RobNYC

[Ron Rich]

Andy,
I think Rob pretty much got it--but I am thinking it's the clutch member too-- check the adjustment, and LUBRICATION of pick-up #2-- ( got my "Seeburg Mechanism Guide" ??--see comments on the lube charts )--- Ron Rich

[andylevine]

robnyc - Yes, records come up...sometimes not the right ones...I still have to troubleshoot it skipping a slot every now and again. According to Rons guide I cleaned 2M1 and the DCC relay contacts to no avail. Was going to make sure that Tormat bits are aligned properly next. Ron Rich - I sleep with your guide by my pillow..... Will look at pick-up 2 when I get home

Thanks again
Andy

[andylevine]

robnyc and Ron Rich - DEFINITELY a clutch issue. I finally got a decent look when it did it at the 200 end of the rack. The clutch shaft worm gear seems to disengage from whatever is behind it driving it. This only happens on B sides. A gentle nudge to the left on the stripper plate and it re-engages and all starts working again. Best to run through the clutch adjustments???

[Ron Rich]

Andy,
Nope-- Not a clutch "adjustment" problem, unless "someone" has been "messing with" them ? --Possible top/bottom, thrust bearing problem on the clutch housing-worn clutch member, Detent lever roller loose on post (or post swedging loose), loose long shaft that holds the clutch bearing block on the clutch yoke. And--last I can think of now--#2 cradle adjustment too tight (although would not think the side of the record playing would mater--see if it "bounces" anytime it does not need to, and does not change sides ?). Ron Rich

[andylevine]

Ron Rich I assume by “#2 cradle adjustment’ you’re referring to what in my manual is called ‘Pickup adjustment 2’ Where one leave just a quarter turn on pickup screw 2 to allow a little up/down play in the tonearm?? Pulled mech out of cabinet and verified that looked good. VERY difficult to see/verify if top clutch bearing is off. I did pull the little ball bearing out and added a tiny bit of grease to the end cup it’s sits in when I pulled and cleaned clutch.

robnyc - yes the roller is there an oiled along the cam on the outside (that’s the brake cam, right?) the spring for that sucker is very strong and holding roller tight to cam.

Spent about an hour playing with this and can consistently get it to fail choosing 101 then 204. It’s about the only place I can get a peek of the clutch in action. Is there a way to bench test this to make my life easier?? I

[Ron Rich]

Hi Andy,
Yep--#2 adjustment in service manual-- You can build a bench service cord using the compatible Molex socket to the Mech plug--I built one many years ago--fuse it at no more then 6/10 ( 1/2 is better) slo blo. Install a power switch, and if you wish, populate the 25 volt pins so you can power the detent coil with another switch (or you can manually lift the Detent lever). Or, you can remove the DCC from the phono, and power it from the DCC. Try the following-select 209, then 208, then 207--and so on--does it "jump" after the first one of this series ? Ron Rich

[andylevine]

Ron Rich - 209,208,207,206,205 - yes, that sequence seems to jump and miss quite a bit. Sometimes i'll get 2 'good ones' in a row, but the few times I tried one missed/did the chunka thing on every one, another was miss, ok, ok, miss, miss. 105,106,107,108,109.... Never had the issue described (chunka, chunka), but each run it did skip a slot, so 105,106, 108, 109, 110, or something like that. It does seems to jump or stop more violently than my B.

[Ron Rich]

Andy,
I'm lost--now it's skipping selections--too ? Do you have a copy of my "Seeburg MicroLog Trouble Shooting Guide" ? If so, see if you can pin it down further-- Ron Rich

[andylevine]

Ron, yeah I’d mentioned earlier in the thread it occasionally jumped slots. And yes, I have your Microlog Guide, bought direct from you when I bought this box. I already cleaned 2M1 and the DCC relay contacts to no avail, which kept bringing me back to worn clutch member. I get home tomorrow and will spend some time with this beast again.

[Ron Rich]

Hi Andy,
OK--from what I can determine, from what you have written, either you have a totally worn out clutch member, or something dry in the clutch area, or a loose (large) block bearing holder (on the clutch), or a loose roller under the detent lever -- Let me know what you find--Ron Rich

[andylevine]

FINALLY getting back to this, I'll take you suggestions one at a time Ron Rich :

1) "Totally worn out clutch member"  - I'm not one to know, but it doesn't look TOTALLY worn out. I now remember robnyc commenting on a pic of the clutch I posted a while back on Facebook that I had some wear on one of the bottom corners(?) and that a filing might help. I completely forgot about that when I reassembled the clutch last time. I just now totally UN-assembled the clutch to see all the things you mentioned above and took these pics:

  

Totally worn out???  You're a much better judge than I!  Also a few other things to notice:  1) it looks like someone may have already filed these notches in the past - I see some marks that could be file marks??  2) I just noticed there is a taller/bigger side and a slightly smaller side to the clutch member...Did I assemble this properly with bigger towards bottom, or is this supposed to be symmetrical??   3) the long pin coming out of clutch yoke and through the clutch yoke lever.... it looks like there the COULD be an e-clip there in the end of the pin, in that groove.  There wasn't one when I originally disassembled and my manual doesn't show one.  Should there be one??

2) "Something dry in clutch area"  - does not appear to be.  Seems as well oiled in all the bits as to when I reassembled a few weeks ago.  Yoke shifts effortlessly up and down, blocks ride in member smoothly with no skips or jump, detent arm roller oiled and rolls easily

3) "Loose large bearing block holder"  - I am assuming you mean the pins inside the yoke that hold the bearing blocks??  These don't appear to move at all

4) "Loose roller under detent lever"  - The only play in this is the slight up/down on its pin between the e-clips holding it in place.

Thanks
Andy

[Ron Rich]

Hi Andy,
Yep--looks (from here) to be very worn--also, hafta agree--looks like it's been filed ! You can't assemble it wrong--see your service manual, and or my Seeburg Mechanism Guide. I would change the member. You sure the yoke, and detent lever #2 ride freely on their support pin--Pin should NOT move with either section.
Slip your screwdriver into the area with the large bearing block pin-- can you wiggle it at all ?--Should not move a drop, in any direction ! No e clip needed.
Up/down is OK on the detent roller--no "left right play" at all !! Ron Rich

[andylevine]

The replacement NOS clutch member came yesterday so I took the time to replace it. Did clutch adjustments 1-4 (2 was WAY off) as well as Tormat and contact block adjustments and everything seems great so far. Thanks again to Ron Rich and robnyc for sharing your wealth of knowledge! Next problem coming up......