I just finished cleaning and relubing an 83 Trek 520. The Suntour dt shifters still do not work smoothly and the friction tension is basicly either too tight or too loose. There does not seem to be a middle ground. On the far inside of the lever there is a thin metal 'washer' that still has some rust on both sides of the washer. It is so thin and delicate I was afraid to do much to it. Is this the reason for the poor shifter feel?

BTW...I was pleasantly surprised with the good ride of this bike. It was not slow and sluggish as I had expected. Really a nice ride and I may keep it instead of selling it as intended.

www.ventoux.com/suntour_Id500 about as good as any. Appears typical to me. I do believe the answer lies in the washer. Perhaps replacing/adding to what appears to be the relavent washer could be tried, a sort of generic, maybe sealing ws.(like a water fawcet) or a linkage ws. at a parts store or the stash at an LBS. I used one out of a fishing reel years ago, I'd lost the original.

www.ventoux.com/shifters.html

Thanks for the exploded views. The ones on this bike do not have anywhere close as many parts as the view shows. These only have lever stop against the frame boss, then a thick plastic washer with a double 'd' hole, rusty washer, lever, thick plastic washer with double 'd' hole, small dia alloy washer, and then the tightening wing nut with a wire gripper.

Yeah that exploded view is of SunTour Power (ratchet) DT shifters. Was ST still making non-ratcheting friction shifters in the '80s? If I were less lazy, I could go do a search...

But yes, as has been said, rust in the "system" will bung things up. Take the corroded washer and make the rounds of hardware and plumbing stores until you find something similar.

Yes, Suntour still made straight friction shifters in the 80's. The biggest mistake with friction shifters usually made is to lube them up with grease or silicon. If they won't hold, pull them apart and clean them really good removing all grease and rust, then put them back together again and tighten accordingly. They should be as good as new.

I did use a hint of grease on the internals but I have used it many times and never had this problem. I will see if I can find a replacement washer or maybe use a fine abrasive to remove the rust on the current rusty one. I will also remove what little grease I did introduce into the shifter

Thanks for the suggestions

It does seem to feel a lot better but was dark so I did not get to road test it yet. Thanks to all