I have a 3700 2009 Trek MTB and am having trouble getting it to the highest gear.
The gear says Shimano Acera, and it has click style shifters. I can't have the gear on the left at "3" and then get the one on the right to "7". The gear says 7, but the chain doesn't swap over. If the left gear is at "2", then the right can change over to 7. I can then pop the left side into "3", but either the chain keeps slipping over and eventually shifts, or it shifts right away and rattles.
What is the adjustment?