I have a manual transmission hhr 2008 it wont go in first or reverse I have noticed the shifter got real stiff if I work at it eventually it will go into gear

 

Try lubing the shifter cables

 

I don't know if the LS/LT has a similar setup. The SS manual shifter has adjustments for this sort of thing.

 

I would look at the top of the transmission while my lovely assistant moves the shifter around. If this is a new thing it may be that one of the connections has popped off.

 

if only 1st and 5th, but the rest is flawless - then this is the problem of the switching mechanism (most likely) ...
Damaged Cables (hairy) or plastic bushings of cables (worn out).
It often happens that the bolts of the manual transmission switch device are loosened, it is treated by simply tightening the bolts back to normal.

but, if after testing the switching mechanism you do not find breakdowns, then it is possible:
Clutch malfunction,
the fork is cracked or the release bearing is worn out,
Incorrect operation of the jet thrust of the transmission,
Wear of the bearing of the input shaft of the gearbox,
Deterioration of box synchronizers. Synchronizers are brass bushings that ensure the alignment of the speeds of the driven shaft and gear when the gear is engaged.
It's all more expensive and labor intensive.