Need to replace Shimano 600EX 6-speed index downtube shifter
 

My shifter went out on my '87 TREK 560EX. It has the downtube braze-on index 6-speed shimano 600 shifter set. I have not been able to locate a replacement. Any options? Anyone know a good place to look for one? What if I were to get a 7-speed or 8-speed shifter- would I just need to replace the freewheel with a 7 or 8 speed? Did they make those in freewheel designs, or is that when they switched to cassettes?

Freewheels are available in 6, 7 or 8-speeds. 8's aren't recommended due to spacing issues so I'd stay with a 6 or 7-speed set-up.

You can replace those with any kind of Shimano 6sp index shifter (light action, 105, Exage Sport/Motion/Action.) They all work fine. No need for 600EX (make sure that if you get one it is the SL-6208, and not the SL-6207 part that is friction only)

Well, I found a replacement, but the infamous tabs broke off instantly. I would like to use and trust this bike, so I should probably replace both shifters with something newer or more reliable. I have read on Sheldon B's site that that particular shifter had the aforementioned design flaw. So, can I replace the shifters and the freewheel with a 7 or 8 speed setup? I think my r.d. will work with either. The rear wheel spacing is 126mm. Any thoughts on what to look for?

If its 126mm spacing you'll want 7, and as mentioned above the Shimano SL or 105 7 speed shifters are nice and can be had on ebay pretty reasonably.

I don't suppose I could use 7-speed shifters and keep using the 6-speed freewheel? If I need to get a freewheel, does it need to be a shimano HG 7 speed? Thanks for your help

I tried that with poor results. IMHO, you are much better off with a 7 speed freewheel. I believe there is still an aftermarket freewheel that is more of a road gear than MTB, but it's not Shimano brand, I'm not sure who makes it.

Try thethirdhand.com (Loose Screws). They have 6 speed 105 shifters for $35.

I Just put a 8 speed hub on the Trek 560. Went in easy. Haven't decided if I am going to use friction mode or swap in the 8 speed downtube shifters
I have in a box. Also I saw these Diacomp shifters they look nice.