I have a Husqvarna 48" Lawn Tractor (model YTH 2448 - 960150001 - automatic). I am trying to put on a new motor drive belt and secondary drive belt. I can't get the secondary drive belt on. There is not enough slack in the belt. I know I have the correct belt and routing for the belt. I've tried stretching the spring but can't get it to stretch far enough to get the belt over the left mandrel. Is there some way to adjust the tension of the belt? The manual isn't very helpful it says the following and doesn't mention adjusting the tension. Any help would be appreciated.
INSTALL NEW MOWER BLADE (SECONDARY) DRIVE
BELT
Install new belt in lower groove of R.H. mandrel pulley,
idler pulley, and center mandrel pulley as shown.
Carefully roll belt over L.H. mandrel
INSTALL NEW MOWER BLADE (SECONDARY) DRIVE
BELT
Install new belt in lower groove of R.H. mandrel pulley,
idler pulley, and center mandrel pulley as shown.
Carefully roll belt over L.H. mandrel