Sorry to chime in late.
Have ESOF on my truck. Transfer case always shifts in or out. Front hubs always lock but one or both front axles never unlock. Wiggle steering wheel back and forth, drive backwards several hundred feet but no good. I had to crawl under the truck and grab each axle and rotate the drive axle back and forth until I felt the hub unlock.
I've now disabled the vacuum system to the front hubs by unplugging the hoses at the vacuum solenoid mounted on the right inner fender under the hood and plugging the hoses. Now if I need 4 wheel drive I manually lock the front hubs them activate the dash ESOF switch. When I no longer need 4 wheel drive I turn the ESOF switch to 2WD and manually unlock the hubs. Hubs always, always unlock now.
As a side note I have read that some truck owners feel that the vacuum system may be the cause of early front hub bearing failure. The thinking is that the vacuum may be responsible for pulling the grease out from the bearing causing the bearing to operate dry.
Have ESOF on my truck. Transfer case always shifts in or out. Front hubs always lock but one or both front axles never unlock. Wiggle steering wheel back and forth, drive backwards several hundred feet but no good. I had to crawl under the truck and grab each axle and rotate the drive axle back and forth until I felt the hub unlock.
I've now disabled the vacuum system to the front hubs by unplugging the hoses at the vacuum solenoid mounted on the right inner fender under the hood and plugging the hoses. Now if I need 4 wheel drive I manually lock the front hubs them activate the dash ESOF switch. When I no longer need 4 wheel drive I turn the ESOF switch to 2WD and manually unlock the hubs. Hubs always, always unlock now.
As a side note I have read that some truck owners feel that the vacuum system may be the cause of early front hub bearing failure. The thinking is that the vacuum may be responsible for pulling the grease out from the bearing causing the bearing to operate dry.
