Rear Derailleur Pivot Bolt Stuck
Looking for some repair advice:
I have an older Shimano XT rear derailleur (M737) with an aftermarket SRP Rear Pivot Bolt that I can't seem to remove. I took the first retaining clip off the derailleur (just below the threads of the pivot bolt) and removed the tension spring from inside the body. All that's left is the pivot bolt and dust seal, but they will not come out of the derailleur.
I can't see another retaining clip inside the derailleur body, and I've never had this problem with stock Shimano pivot bolts. The bolt can be rotated, but for whatever reason it won't pull out.
Edit: I've added a pic I found online to show the bolt I'm referring to.
So you already removed the clip that holds the spring inside the derailleur at the main pivot? If so, you should be able to remove the plate and spring. That said, you will have to pound out the pivot bolt with something its size or smaller. Try not to ruin your pivot bolt.
Assuming I am understanding your question, this has happened to me in the past. The area at the pivot and derailleur has become corroded, making it difficult to remove the bolt. When you get it out, use dremmell or rolled-up sand paper to remove the rust/corrosion. Use the thick grease or no-sieze when reinstalling.
I have removed the clip, plate, and spring. Only thing left are the pivot bolt and the derailleur body. I tried pounding a bit last night to no avail - those SRP alloy bolts are soft as butter, and I'm trying not to destroy an already cosmetically-deficient derailleur.
Originally Posted by Pisgah
It's odd that I'm having so much trouble, since all of the other rebuilds I've completed have been fairly straightforward. I wouldn't normally care this much, but I feel like the rotation of the derailleur is a bit sluggish and it needs to be re-greased. I guess I was hoping there'd be another clip somewhere or some kind of retention mechanism.
Thanks for the input, we'll see if I can force it out tonight.
The square edged groove where the clip rests has mushroomed outward. You could try sanding that area, or just use brute force to press the bolt out. Just went through the same thing a few months ago with my own vintage RD and aluminum breakaway bolt.
In my opinion, if you have removed all the guts of the pivot area and the bolt will not come out easily, you have no choice but to pound it out. You can always get another pivot bolt. Try using a vice or socket to place the derailleur on when driving the bolt as you hammer (carefully).
Originally Posted by jtmartino
Yeah I got the bolt halfway out and the aluminum started to mushroom. I'm going to have to drill it out, and hopefully not damage the derailleur any more than it already is.
Normally I wouldn't care this much about a $10 used derailleur, but it's part of a M737 group I picked up that's going on an older build I'm working on.
Thanks for the all the input!
Just as an update, I wasn't able to pound it out by any means. I beat the hell out of that thing, to the point where anything I hammered into the bolt just started to leave an indentation in the aluminum. I ended up drilling out the old pivot bolt without damaging the derailleur itself. Replaced it with an old XTR pivot bolt that works just fine.
Word of advice to those looking to use one of those fancy anodized bolts from SRP or anyone else: make sure you use grease when installing!