Spider27 Posted April 30, 2020 Share Posted April 30, 2020 (edited) Hello, I have Jelco tonearm that works great except cueing mechanism or arm lifter. When lever drops, the horizontal level/plate drops a bit then hang there a few seconds then slowly drop all the way down. That hang at the start is annoying and I took it apart and re-lubricated with pure silicone oil 300,000 cst which should have enough viscosity. When I push it down and up a few times then it works smoothly. However, it happens whenever I leave it for awhile and drop the arm again. My initial thought was oil is dirty or old so need to be re-lubricated but it is not the case if I understand correctly. Has anyone have re-lubricated the tonearm lifter successfully before? If so, could you please share one or two tips? Here is the shot of tonearm lifter. Edited April 30, 2020 by Spider27 Link to comment Share on other sites More sharing options...
pwstereo Posted April 30, 2020 Share Posted April 30, 2020 (edited) Is there perhaps a burr or something causing the hang in descent? Distortion of the tube or piston? Some residue or rough spot? Can you assemble the piston at a different rotation into the tube? Maybe it's better 180 degrees turned? I'd probably give the contact surfaces a polish with some 1000 or higher grit Wet'N'Dry abrasive paper. Edited April 30, 2020 by pwstereo 1 Link to comment Share on other sites More sharing options...
Peter-E Posted April 30, 2020 Share Posted April 30, 2020 Tis the season for cue arm damping issues it would seem 2 Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 38 minutes ago, pwstereo said: Is there perhaps a burr or something causing the hang in descent? Distortion of the tube or piston? Some residue or rough spot? Can you assemble the piston at a different rotation into the tube? Maybe it's better 180 degrees turned? I'd probably give the contact surfaces a polish with some 1000 or higher grit Wet'N'Dry abrasive paper. Thank you for the suggestion. I will give it a go later today and report back. Link to comment Share on other sites More sharing options...
GregWormald Posted April 30, 2020 Share Posted April 30, 2020 What would have caused in to get scratched/dinged enough to need polishing? If it really needed polishing I'd be starting only with a cloth or piece of leather. The fit of the slider and tube would seem to be fairly critical. Even the surface texture might be important. If it's just wear then the 180° turn sounds promising. If it only hangs for a second or two that's just enough time to sit back down. Link to comment Share on other sites More sharing options...
pwstereo Posted April 30, 2020 Share Posted April 30, 2020 23 minutes ago, GregWormald said: What would have caused in to get scratched/dinged enough to need polishing? Maybe a previous inexpert attempt at disassembly/repair (not suggesting by the OP)? Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 I cleaned and every bit and relubricated and tried.... And, it does not come down to the bottom but hang at the top.. when I move the lever up and down 8~9 times then it works and comes down smoothly every time after that. However, if I leave it for an hour or so and try again, it happens again. My guess is that the viscosity may be too high (300,000 cst) or inner wall of barrel needs to be lubricated by the lubricated cylinder moving up and down so it goes down without hang? Not sure if this is norm for Jelco tonearm... Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 Left it for an hour and just tested it again and it does not hang this time. Might need to monitor closely to make sure it is definitely working. 1 Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 56 minutes ago, Spider27 said: Left it for an hour and just tested it again and it does not hang this time. Might need to monitor closely to make sure it is definitely working. No... I am wrong. I tried again and it hang on top and does not come down. After 8 times of moving the lever up and down, it works smoothly again. Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 (edited) Cleaned off cylinder and just applied a tiny amount of this thick silicone fluid to the cylinder wall of cueing mechanism and it is better. The quantity of oil must affect the performance of cueing mechanism and too much is worse in this case. Edited April 30, 2020 by Spider27 2 Link to comment Share on other sites More sharing options...
Grumpy Posted April 30, 2020 Share Posted April 30, 2020 Just a smidge is usually all that is needed - after a clean of course. 1 Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 Just now, Grumpy said: Just a smidge is usually all that is needed - after a clean of course. Yep. I continue testing by leaving it idle for half an hour and try again and it is now much better than original status. A drop or two to very thin coat on inner wall of cylinder seem all needed. 1 Link to comment Share on other sites More sharing options...
thejt Posted April 30, 2020 Share Posted April 30, 2020 Hey Jim, if the clearance is very tight anything beyond a very fine film would be problematic. 2 Link to comment Share on other sites More sharing options...
Spider27 Posted April 30, 2020 Author Share Posted April 30, 2020 13 minutes ago, thejt said: Hey Jim, if the clearance is very tight anything beyond a very fine film would be problematic. Hello, Yes, it looks like it is the case here. Link to comment Share on other sites More sharing options...
Peter-E Posted April 30, 2020 Share Posted April 30, 2020 If it was an engine I'd say piston slap. As a joke Link to comment Share on other sites More sharing options...
Spider27 Posted May 1, 2020 Author Share Posted May 1, 2020 From cold start, it is now 3 up & downing the lever, it works smoothly. Definitely improvement from previous 8 times up and down to make it work. Still bit of work to be done to make it work every time without pre-up& down movement. Link to comment Share on other sites More sharing options...
pwstereo Posted May 1, 2020 Share Posted May 1, 2020 Maybe just clean all the silicon lube out and try a light machine oil. Link to comment Share on other sites More sharing options...
Spider27 Posted May 1, 2020 Author Share Posted May 1, 2020 3 hours ago, pwstereo said: Maybe just clean all the silicon lube out and try a light machine oil. I tried it first thing before applying silicon lube and it was no no... It drop it super fast and also making funny fart sound. Silicon oil is the one for sure but I feel that it is the quantity that counts unless I miss something else. 1 Link to comment Share on other sites More sharing options...
pwstereo Posted May 1, 2020 Share Posted May 1, 2020 Maybe a lighter weight of silicon damping oil then. Link to comment Share on other sites More sharing options...
Spider27 Posted May 1, 2020 Author Share Posted May 1, 2020 10 minutes ago, pwstereo said: Maybe a lighter weight of silicon damping oil then. That might be the solution. If I cannot make it work with current oil, might get lighter one to try. I somehow could not find high viscosity silicon oil domestically hence ordered it overseas and it took very long time to arrive. Link to comment Share on other sites More sharing options...
pwstereo Posted May 1, 2020 Share Posted May 1, 2020 9 minutes ago, Spider27 said: ... ordered it overseas and it took very long time to arrive. That's a painful reality for so many low volume specialty things in AU. Good luck with your quest. Link to comment Share on other sites More sharing options...
Spider27 Posted May 1, 2020 Author Share Posted May 1, 2020 Third time cleaning off cylinder and it now works every time (Will monitor closely but it looks like works now every time). I am just surprised how little oil it really requires to make it right. 1 Link to comment Share on other sites More sharing options...
Grumpy Posted May 1, 2020 Share Posted May 1, 2020 3 hours ago, Spider27 said: Third time cleaning off cylinder and it now works every time (Will monitor closely but it looks like works now every time). I am just surprised how little oil it really requires to make it right. YEP. BTW the 300,000 'oil' can be found at some RC car hobby shops - used in the diff gears. 2 Link to comment Share on other sites More sharing options...
vintagehifiportugal2016 Posted January 19, 2021 Share Posted January 19, 2021 Hello Spider27, May I use the photo of the disassembled cue lift mechanism in my ebay listing as well as to send the shot to a lot of international querries that I get? I came across this forum and joined it because you seem to have been one of very few people who has posted your experiences and resolved the issue! On the other forums, nobody had really gone through all the motions and the general concensus was that 500 cSt silicone was also recommended by the manufacturer for fixing the tonearm lift mechanism.....perhaps they did not ask the manufacturers the right question or since Jelco only sell 500 cSt vials, their answer was bog standard (as they used to say in my youth!) Needless to say, my listings are always transparent and the buyer knows and gets the viscosity information in the description....but they can always buy the same thing from elsewhere....I do not sell the magic potion, I tell them what the magic potion is and they can choose to buy it from me if they feel so inclined! Thanks and regards Link to comment Share on other sites More sharing options...
AusMakka Posted July 5, 2022 Share Posted July 5, 2022 I had to do the same with my AT-LP120. I also used 300,000 and at first it was very slow to drop as I put in too much. Took some out and it's been perfect ever since. Link to comment Share on other sites More sharing options...
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