Help needed in solving garrard 401 rumble issue

[abhijitwadekar]

Dear friends,
kindly help me in solving my 401 rumble issue.
Today morning I decided to service 401 which was leaking a bit of oil from the spindle. So out came the thrust plate for spindle. There was adequate oil around spindle. So I fashioned a gasket out of oil seal paper procured from automobile store. Next cleaned the thrust plate and sand papered the contact points a bit. Put the thrust plate back in place and secured it with screws.

Then I opened the motor carefully, cleaned the contact brush points lightly with sand paper and cloth. Refilled the oil sump with a few drops of oil and reassambled the motor properly.

Then mounted the turntable on 3 tennis balls feet and gave the platter a spin. It was extremely quiet and spun absolutely smoothly.
Then I adjusted the speed of tt by adjusting the screw for speed adjustment.

next I mounted the platter back again and a constant scratchy noise started coming as if the platter is touching somewhere while spinning. There was no noise without the platter.

Noise was constant even if I spun the plate and at all speed.
the speed was also not stable and kept varying all the time.
I have tried adjusting the speed but nothing is helping.

Dear friends please help me in finding the fault.
Thanking you in advance for all your advice.

regards, Abhijit

 

[jls001]

Quick question: does the 401 use ball bearing between the spindle and thrust plate? Or is the bottom of the spindle rounded and rests directly on the thrust plate?

If the former, did you put back the ball bearing?

Be careful not to let the platter scrape off paint from the top plate.

 

[abhijitwadekar]

Hi, I did put back the ball bearing properly in place . And the platter is not showing ant sign of scraping against the top plate. Will probably reopen the base plate and take a second look at the bearing and spindle.
thanks a lot for ur resposne..regards. Abhijit

 

[kuruvilajacob]

AS you cannot see any mark on the inner part of the platter, it could be something inside. Why don't you take he platter out and spin and keep a stethoscope on and try to identify from where the sound is coming. I had a rumble noise once on my 301 and this was identified this way.

 

[arj]

if the problem is due to the platter- if possible put a coin below the ball bearing in the spindle (below the thrust plate) this will raise the spindle and hence the platter by a few mm. this has a huge impact on my TT as the platter used to stop in secs earlier and after this it goes on for more than a minute.

 

[abhijitwadekar]

Hi Friends,
Finally i managed to solve the rumble issue with good suggestions from you all and from Mr Hiten.

Mr Hiten suggested that small dust speck must have got in to the bearing as i had lightly polished the thrust pad surfaces with a sand paper.

SO i removed the thrust plate and rolled the ball bearing with my finger and could feel gritty sensation immediately. i removed the ball bearing and cleaned it properly and found small metal dust particles on it.

Then i removed the spindle, cleaned it properly and also the chamber with a cotton cloth wrapped around a screw driver.


Managed to remove few such small dust particles from the shaft as seen near the tip of cloth in the attached photo.

Refilled the shaft with light machine oil after replacing the spindle and then put the thrust plate back on.

With the platter in place gave the TT a spin and the rumble was all gone completely.:yahoo:

My system is back working again and sounding even better thanks to valuable inputs from you all and special thanks to Mr Hiten.

Regards

Abhijit

 

[reubensm]

Amazing info on how this was solved, brilliant!!