TD145 II belt jumps the tracks

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Paul902
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TD145 II belt jumps the tracks

Post by Paul902 » 01 Jan 2020 20:31

Thorens gurus, my TD145 mkII operates superbly on 33, but with 45 RPM the following two things happen:

1. When I go up to 45, the belt moves goes flat at the lever arm, and sits at the bevel of the pulley rather than going all the way up to its flat upper surface.

2. With the platter off, if I manually put the belt onto the proper flat surface of the pulley, it jumps off completely when I move the control to Stop.

Is this time simply time for a new belt, or is something else amiss with the speed mechanism? The belt is a genuine Thorens, but I am not sure of its age.

thanks, Paul.

tlscapital
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Re: TD145 II belt jumps the tracks

Post by tlscapital » 01 Jan 2020 21:11

First. Give a good isopropyl clean with a soft cloth to the pulley, the belt and the sub platter side.

Secondly if not sorted, get a brand new belt. If it's not to replace now, will still be good for later.

Finally, one can always fiddle some with the belt leveler to set it higher if ever it got to "pressed" down.

sausagecreature
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Re: TD145 II belt jumps the tracks

Post by sausagecreature » 04 Jan 2020 11:49

Not sure how helpful this will be (I have a 321), but my drive belt would slip off at speed change or start up. This happened during the first week I had the deck whilst I waited for a spirit level to arrive in the post. Once I had the level, I went through the set up process to make sure I had adhered to all requirements for plinth, platter, arm and stylus. Ever since that was completed the belt works as it should do. The key step was the levelling of plinth and platter for me.

StephDale
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Re: TD145 II belt jumps the tracks

Post by StephDale » 04 Jan 2020 22:43

Paul,

If you haven't changed the belt for a while it'll certainly be worth doing, but some of the TD14x and 16x family are just a pain like that, unfortunately. You can sometimes get the belt to change properly on an otherwise sulky machine by starting at 33rpm, then slip the control knob across to 45 while the platter is turning. It's probably worth doing the reverse before switching off...

Steph

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Re: TD145 II belt jumps the tracks

Post by JDJX » 05 Jan 2020 03:41

There was a recent thread on this exact issue and it's an easy fix

This what I wrote....with a couple of minor additions ..... and it easily fixed this common issue for the poster...
You must also clean the belt and keep it clean.
Use a few drop of dish washing liquid on something like cotton moistened with water and gently draw the belt through it
I use cotton "makeup rounds" for this..

You will be surprised at the crud that comes off the belt
IMO, often belts are replaced that simply need a quick cleaning .
If you only clean the pulley and inner platter, and not also the belt, it's all for naught

BTW, I use cotton "makeup rounds" for this.

Use isopropyl alcohol to clean the pulley and sub platter where the belt contacts. [/quote

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Re: TD145 II belt jumps the tracks

Post by JDJX » 08 Jan 2020 16:17

The OP seems to be MIA. :)

sausagecreature
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Re: TD145 II belt jumps the tracks

Post by sausagecreature » 08 Jan 2020 18:43

They so often are ;-)

JDJX
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Re: TD145 II belt jumps the tracks

Post by JDJX » 08 Jan 2020 19:35

OK.. I found the original thread with this exact same common issue with the vintage Thorans ....
viewtopic.php?f=17&t=114334

Paul902
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Re: TD145 II belt jumps the tracks

Post by Paul902 » 09 Jan 2020 23:24

JDJX wrote:
08 Jan 2020 16:17
The OP seems to be MIA. :)
I have been down and out with the flu!! Still trying to get better. :)

Thanks everyone for the responses. I think I did clean the belt, platter and pulley when I got the Thorens a year or two ago, but I'll give that a go and see what happens. My platter and plinth both show pretty darn level according to the little spirit dot I have. So, if an additional cleaning does not solve this I will dig up that belt comparison thread again and get a new one.

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Re: TD145 II belt jumps the tracks

Post by JDJX » 10 Jan 2020 00:30

I hope that you are feeling better. :)

If the last time you cleaned everything was a year or two ago, it is way over due for another thorough cleaning ..... pulley, inner platter (where the belt rides), and the belt :)

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Re: TD145 II belt jumps the tracks

Post by sausagecreature » 12 Jan 2020 09:31

Welcome back to the land of the living :-)

I had to calibrate my spirit level, it wasn't very level. The clue was if I turned it through 180' it would show a different reading.

Paul902
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Re: TD145 II belt jumps the tracks

Post by Paul902 » 13 Jan 2020 16:49

Still under the in-flu-ence, but well enough to have a little go at the TT:

- I recleaned the moving parts with isopropyl. Some black residue did come off the belt, but the other parts seemed clean.
- I rechecked the level with my 2' carpenters level, and sure enough it needed some lift on the back corners. Accomplished that with furniture pads under the feet.

The problem still existed, however. I carefully watched the belt with the platter off as I switched between 0/33/45 rpm. I noticed that the starting impulse going from 0 to 45 rpm when the mechanism was already in 45 rpm would cause the belt to rise above the top of the pulley for an instant, and that a subsequent stop would jump the belt off. This is azimuth, me thought.

The manual states one should turn the screw counterclockwise if the belt rides too high. This is counter-intuitive to me. In fact I could adjust the screw with the TT running and see the belt move up and down. Conclusion was I did not have enough adjustment clockwise. I moved the washer from underneath the plinth to on top, reset the azimuth, and all seems to be good now. I had put the washer underneath when I repaired the motor after purchasing the table, as this seemed to be the arrangement shown in the service manual. Do you all have the washer underneath against the spring, or on top of the plinth?

Thanks JDJX and sausagecreature for your help and suggestions!

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Re: TD145 II belt jumps the tracks

Post by ddarch » 14 Jan 2020 13:12

Washer on top.

Paul902
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Re: TD145 II belt jumps the tracks

Post by Paul902 » 14 Jan 2020 18:35

ddarch wrote:
14 Jan 2020 13:12
Washer on top.
Super. Thanks, David.

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