Thorens TD124 mkII idler wheel not engaging

[jonah1979]

Spent a good amount of time on AK and other sites but can seem to troubleshoot this. I should note that this is my first Thorens TD124 mkII so I’ve never experienced one in top working order.

When I bought the turntable the idler wheel seemed to have issues with engagement. I’ve since gone through a detailed cleaning as per the many resources online and while everything is running and functioning great, the idler wheel does not engage the inner platter. It just sort of flops around (I understand that with the platter off it will not fully engage).

I’ve cleaned, lightly polished and lubed all linkage parts and there is no gummy build up of old lube.

Could it be the spring has lost tension? Does the underside of the stepped speed control cam have to be greased?

Any help would be appreciated!

 

[adnick]

So what’s the actual symptoms you’re experiencing? For instance what’s the speed at 45 & 33 rpm?

 

[Lapslah]

Could it be engaging but not spinning? The inside lip of the platter can seem clean but still slip when the wheel makes contact if there's the slightest bit of oil or grease residue. Give it a good scrub with alcohol if you haven't already. Does the wheel spin freely by hand on its spindle?

 

[adnick]

Also, here’s a link to a manual and the website is one of the best TD124 reference sources available…

http://www.theanalogdept.com/images/spp6-pics/TT%20manuals/Thorens/TD124.pdf

Andy

Spent a good amount of time on AK and other sites but can seem to troubleshoot this. I should note that this is my first Thorens TD124 mkII so I’ve never experienced one in top working order.

When I bought the turntable the idler wheel seemed to have issues with engagement. I’ve since gone through a detailed cleaning as per the many resources online and while everything is running and functioning great, the idler wheel does not engage the inner platter. It just sort of flops around (I understand that with the platter off it will not fully engage).

I’ve cleaned, lightly polished and lubed all linkage parts and there is no gummy build up of old lube.

Could it be the spring has lost tension? Does the underside of the stepped speed control cam have to be greased?

Any help would be appreciated!

There appears to be missing items on top of the idler shaft, unless you removed them, and that would make me wonder about the plastic washer&fiber washer(s) that should be underneath the idler?

Service manual

http://www.theanalogdept.com/images/spp6-pics/TT%20manuals/Thorens/TD124%20svc%20man.pdf

 

[jonah1979]

So what’s the actual symptoms you’re experiencing? For instance what’s the speed at 45 & 33 rpm?

At this point speed isn’t an issue as it’s not spinning at all because there is no contact between the idler wheel and the stepped pulley - with the platter on or off. If I preload the spring with an extra twist it will work but worry this isn’t a great solution and I’m missing something.

Could it be engaging but not spinning? The inside lip of the platter can seem clean but still slip when the wheel makes contact if there's the slightest bit of oil or grease residue. Give it a good scrub with alcohol if you haven't already. Does the wheel spin freely by hand on its spindle?

Yup spins freely and everything is clean.

There appears to be missing items on top of the idler shaft, unless you removed them, and that would make me wonder about the plastic washer&fiber washer(s) that should be underneath the idler?

Nylon bushing is under the wheel and didn’t seem to need the height with the fiber bushings. There is a collar on top that is currently off.

Perhaps the spring is weak? Do I need to add grease to the speed change cam… where the spring pin hits?

 

[adnick]

If the washers are in place, with the retainer ring attached, there should be at least 1/64th” play and the idler should not rock side to side…but if the platter isn’t turning at any speed, put the washers and retaining ring on, then turn the table on to 33rpm and move the idler shaft over against the step pulley, note if any of the belt pulley’s or the belt slips…

Andy

 

[jonah1979]

Yes. Everything works correctly when I manually push it against the step pulley. That's the problem, it doesnt work when I'm not pushing against it from underneath or preload the tension spring in the idler wheel linkage (which is not a great solution). Hmmm...

 

[adnick]

Yes. Everything works correctly when I manually push it against the step pulley. That's the problem, it doesnt work when I'm not pushing against it from underneath or preload the tension spring in the idler wheel linkage (which is not a great solution). Hmmm...

Ok here’s a photo of mine with the speed selector off, and the other with it shifted to 33rpm

Yours should look similar with the same selections..






Note that the idler touches the step pulley when shifted to 33rpm, not enough pressure to turn but it’s there…

 

[jonah1979]

Note that the idler touches the step pulley when shifted to 33rpm, not enough pressure to turn but it’s there…

Sadly mine doesnt even touch when it's set to 33 or 45... If I preload the spring with an additional turn it works, but with the spring it's normal configuration, it doesn't have the strength to make it to the stepped pulley. Should I just run with this and accept that perhaps the spring is shot? Or might there be something else?

 

[adnick]

With everything together, table unplugged and the the platter off, turn the speed selector slowly between speed(s) does the idler ever get close to the step pulley at the different heights, If so note when….

There’s a couple of mechanical things (related) that might manifest as you describe, very hard to guide your actions, without seeing/interacting with the actual turntable.

Theanalogdept is the best resource I know of to learn about the mechanics of the TD124…

Andy