Why is it hard to put in gear?

Take it to the shop. Sounds like your clutch brake isn't working right.

One thing you can do until you get it to the shop, is to put it into whichever gear you will be starting out in, as you are coming to a stop. Just do a standard down shift.

 

If you can feel the clutch brake in the clutch pedal before the pedal hits the floor and there is no grinding when attempting to put it in gear then try letting up slightly on the clutch pedal as you move the stick into position to go into gear. The transmission needs to be allowed to align gear teeth to engage in the gear especially in a good tight transmission with a good clutch brake.

 

This probably happens when engine is warmed up. the clutch need adjustment, more likely at the linkage, not on the clutch itself. until you can get it looked at, with clutch to the floor, at a stop, if it will not go in gear, try to let up just a little on the clutch pedal & see if it will go in. when I fist got my truck, the clutch brake was not letting me put it in gear, like it should. even after new clutch put in, it went in easier, but not like it should, until I talked to my local shop, who DID NOT INSTALL THE CLUCTH, but any way for 30.00 he adjusted from the likage, just under the front bumper area. since then it works like a new one,no problem.

 

What he said, I learned this many moons ago, and heavyhauler ss is also right about needing an adjustment to the linkage from time to time, but won't cause this but rather a very slight grind as you attempt to go in gear.