OK, this is a good one. Some owners of 2006-2010 Hummer H3 vehicles may complain about difficulty when shifting into reverse or blocked shifts on the Aisin MA5 manual transmission.
According to GM, a customer can expect a blocked reverse shift 10 times in 50 attempts.
Engineering has determined that this condition is an inherent characteristic and should be considered normal. A higher frequency of block outs may be considered abnormal.
The correct procedure to follow is:
1. Shift into 1st gear.
2. Move the vehicle forward slightly.
3. Stop and shift into reverse.
Shifting the transmission into reverse while the vehicle is moving will increase the tendency to block-out due to damage of the meshing teeth and would be considered abuse.
Just tell the owner not to park with the nose directly up to a wall.