Reason 1: when you accelerate, weight is shifted rearward giving the drive wheels more traction.
2: Birfields are a week point in the drivetrain.
3; experience driving a 40 in front wheel drive (rear shaft removed for repairs) has shown me that the front wheels are easily spun. If spinning...
It is recommended to lock in the freewheel hubs for a few miles each month to keep things lubed up.
Engagement into H4 while they are locked should only be done on slippery surfaces… but now and then you may have good traction between slippery surfaces. If you have good traction things will...