To upgrade/repair or not...Thorens TD165

Leave the tonearm wire and cable alone! Honestly, spending hundreds to replace them is a waste of money! Some oil lubrication of the main bearing and a new belt is all you'll need!

I have a Thorens TD125/Rega and a TD160/SME IV in my collection of vintage TTs. Both excellent - as is your TD165. No need to buy something new! 

You can start with a $90 Grado and a $129 Schiit Mani phono stage. A very good combination! After this the sky's (or your wallet's!) is the limit - depending upon how obsessed you want to get!

Agree with roberjerman...

Just properly clean and relubricate the main bearing and replace the belt for starters.

I played around with a stock TD165 around 20 years ago and was surprised @ how good it sounded once cleaned/re-lubed and setup.

I used a Grado Silver (they were under $100 @ the time) and a vintage high end Pickering.
 
I also tried many of the popular tweaks, but ended up preferring it stock sans the bottom plate.

I ran new tonearm wire on the "outside" of the arm @ one point, but ended up using the stock tonearm wire and simply replaced the RCA's @ the ends of the stock/attached phono cable.

I also replaced the power cord with an inexpensive "Absolute" cord (cut the IEC off and hard wired it).

If you decide to ditch the bottom cover (my favorite tweak) leaving it open you will need slightly taller soft rubber footers, or you can shim the original footers.

Anyway, I gifted it to a family friend who as of a couple years ago still had it and was using it in his studio for sampling and general fun/listening.

I gave him a couple of Stanton 500 bodies, a slew of replacement styli and Two extra headshells as quality replacements for the Pickering were getting difficult to find.

In case you have forgotten you have to access an inner platter lock from the bottom in order to remove the little/inner platter (to get to the main bearing).

Also be careful that the ground wire does not become detached during the process (think it's around the "lock").

I use/used Singer sewing machine oil in all my Thorens decks except for the TD121/124 models which required somthing different.

Think I used lighter fluid to clean the bearing, but better to research what users suggest now.

DeKay