Fluid leak 4WD actuator, on transfer case
 

I have a 2003 4-Runner limited, V8 Automatic, 4WD. Ruins great, over 100,00 miles. The actuator on my 4wd transfer case is leaking gear oil. Dealer tried to silicon seal the o-ring, but leak continues. Two dealers have estimated $1500 to replace this actuator. Looks like a simple bolt-off and bolt on replacement. Does anyone know the difficulty (or OEM part cost) to replace a 4WDactuator on a2003 4-Runner trnansfer case? Has anyone seen this problem on the 4 Runner 4WD?
Galen Davis
Phoenix, AZ