My tub drain is clogged. From what I have read on this site it is because the linkage on the plug needs to be adjusted. My linkage seems to have disappeared? Most likely causing the back-up. I need some type of conformation before I remove the tub. I can't see anyway to possibly replace the plug system without removing the tub. I have read about the tool you can get at Home depot to do something but I just don't see how it is possible. Maybe I will have to replace the tub? The house is 75 +years old. Thanks

No need to replace the tub. Simply clear the clog. Unscrew and remove the overflow plate,(The one with the drain lever) and pull out the tub stopper. You now have a clear shot at the trap.(see image) Now feed the cable( 1/4" best or 3/3" with a small tip. You can rent a Ridgid K50 sink cable.) About 2' down you will run into the bend of the trap. Crank and push at the same time to work around it. Your blockage will be found in the lateral pipe going to the stack. You shouldn't have to put out more then 10 or 12 feet. I have found tub and shower clogs to be mostly hair and the worm should auger into it and pull it back. Hope this helps and thank you for rating my reply. TOM

Thanks for the info. My problem is that when I remove the over flow there is nothing there. The push rod gizzmo is gone, I am assuming it is somehow blockiing the drain because when I stick a coat hanger down the drain it is hitting something solid about 6 inches in. My toilet is within 2 feet of the tub and the tub drains into the same vertical pipe as the toilet. I changed the seal on the toilet a few weeks ago and I could see the tub tie into this pipe, meaning the whole tub drain is less than two feet. The original plug is long since gone from the tub so I don't know what sort of mecinisim is pluging the drain. Its hard to see down the over flow pipe, maybe I can fish something out of it though.

You have a Bucket, (plug) type tub waste and overflow, (see image) With the bucket still down there. Put a small hook on a coathanger and go fishing.
Once the plug's out of there you can snake the drain line. Tell me what you fish out and I'll give you instructions on how to install it back correctly. Good
Luck, Tom