Why does the helical gears imported from Solidworks Toolbox for an assembly intersect.?

I am designing a helical gears assembly, for that I took helical gears from the TOOLBOX of Solidworks. Doing the assembly the teeth of gear and pinion are intersecting.

I took the following value as a design parameters:

Gear :
module = 2.5mm
no. of teeth = 53
Left hand design
helix angle = 25deg
pressure angle = 20deg

pinion :
module = 2.5mm
no. of teeth = 19
right hand design
helix angle = 25deg
pressure angle = 20deg

Center-Center distance calculated to be 99.30401271mm

Can any one help me with this ? Also how to manually design the helical gears ?