300E fan belt

Help, I'm loosing my mind. I just replaced the Bearing Bracket on my 89 300E. This bracket contains the bal bearing assembly for the radiator fan shaft and I can't get the fan belt back on. I have checked to make sure that the belt path was correct and it is. I have tried prying the tensioner pulley using a crow bar but it just seems too tight and I haven't been able to get the belt on. The reason for replacing the Bearing Bracket is that the bearing within was spun. I'm thinking that the failure was due to the belt being too tight. I'm just amazed at this design requiring such a high belt tension. Those type of belts typically don't need to be that tight. The pros must use a special tool. Please advise.

Thankyou for your support,
SteveD