Bicycle Mechanics - Shimano shifter problem

I have Shimano 105. My left shifter now has a problem. During yesterday's ride, I noticed a slight cliking sound coming from the front on the shifter. The little piece on the front that reads "105" is a little loose. No problem I continued my ride and halted the rattle by putting my finger on the front of the brake assembly. On a long, bumpy downhill the noise became really loud. By the bottom of the hill the "wedge" (sorry I don' know the name of that part, I can only describe it), had worked itself loose to the point where it could be easliy rotated by hand. I grabbed a rubberband that I use to wrap my spare tube and wrapped it around the assembly which worked as a quick fix.

Question is how difficult is it to repair? I assume there is a screw on the inside of the unit I can tighten. If there is a screw there, it is probably located right against the handlebar. How difficult is it to get access to that screw. Do I have to dis-assemble the brake unit to get to it? Or do I need to replace the shifter. I was thinking of upgrading to Ultegra anyway. Maybe now is the time for the upgdrade.

Remove the part with the logo on it(You may break it getting it off), you should be able to get to the screw and tighten it up. The plastic piece might be damaged, you can get a new one with the logo cover fairly cheap.

After I broke mine when taking it off, I found a Shimano service bulletin that said they need to be taken apart and locktite applied to the screw. I used this as a way to get a new cover as a warranty repair for free.

After I broke mine when taking it off, I found a Shimano service bulletin that said they need to be taken apart and locktite applied to the screw. I used this as a way to get a new cover as a warranty repair for free.

Thanks for the advise. I tried releasing the front brake cable to see the screw in back, but to no avail I have sealed it with electrical tape for now. I have ordered Ultegera shifters and will upgrade when they come in. I will try to waranty thing when I remove the old ones.

If you are going to spend the money to upgrade from 9-speed 105 shifters to Ultegra shifters it would make good sense to go 10-speed. All you need are the shifters, cassette, and chain.

Al