kmart

I have a mountain bike with an RDM-952 rear derailleur. The bolt that attaches the derailleur to the hanger has the B-tension spring around it, which lets the derailleur guide pulley move closer or farther from the cassette. My problem is that the derailleur wobbles around on this bolt a little bit and if I tighten the bolt so that it doesn't do that any more, it prevents the derailleur from rotating around the bolt and kills the B-tension. Here's a picture with the problem area circled in red:
RDM952RP.png

I think it's just got some dirt built up around the B-spring so that when the bolt is tightened, the C-clip and dust seals are compressed so much that the B-spring cannot overcome the force. If I just remove the C-clip and dust seal I can probably clean it out and put some grease in there, but I'm afraid the spring is going to unwind and be very difficult to put back in. Does anyone know how to go about fixing this?

kmart

Well, I guess I found the answer to my question: yes, you can pretty much strip this derailleur down to nothing. Here is an extremely detailed description of how to do the overhaul:
https://pedaldamnit.blogspot.com/2008...-overhaul.html

Wordbiker

Switch to XT.

1/3 the cost, less problems. If you're not racing with a support van at the bottom of the course, XTR is troublesome.

kmart

I got it dirt cheap, so if it does come to the point of being irrepairable, I will probably replace with XT. But it seems XTR is built to be serviceable - everything comes apart and goes back together. Even the pulley bearings are serviceable (although pulleys are cheap).

masiman

XT is also built to be serviceable:

XT Parts Diagram