Restored these from a 2007 27 speed Haro Sonix.
Sometimes the trigger mechanism doesn’t “catch”, and it will allow me to push the trigger without pulling the cable? Anyone know the cause of this?
Old Deore shifter doesn’t catch?
byu/mikewoods26 inbikewrench
by mikewoods26
7 Comments
Could be gummed up grease inside, take it apart as much as possible soak in warm water clean as best as you can and lube it with some fine mechanical lube. Pleas correct me if im wrong
This is common among aged Shimano shifters. I usually just flood it with degreaser (directly into the cable port). Do this several times while continuing to actuate the shifter. Typically, in a short time (couple/few minutes) it will begin to engage. Once this happens keep going until it engages reliably. Allow it to dry out for half an hour and then finish by flooding with some lubricant (I use chain lube for dry conditions and have great success).
Bonus points if you can find the pawl that is on the escapement wheel and jiggle it around
Having taken apart and attempted repairs on a fair amount of these, the prevailing failure is the edge shears off of the engaging pawl that advances the internal gear wheel. You can try a flush, but if that fails, it’s likely time for the parts bin.
My trick is
1) remove the plastic cable changing plug.
2) spray a ton of lube in the hole.
3) shift.
80% of the time it works every time.
If the degreaser doesnt help:
sometimes, it helps to press/force the Trigger upwars while shifting.
or some heat. or both.
I am amazed at how often flooding a balky shifter buys more time.