can the 4wd be stuck in 4hi even if the switch says 2hi and there are no idot lights on the dash?
When driving down the road you hear a roaring sound. Also the problem started when my
mother drove in 4wd during a flood in deep water seems like the front hubs are not
From your Mom driving in the high water, water probably seeped into the front hubs/front differential making the roaring noise and not engaging. Have someone look it over. You might have to replace the axle seals, and or drain and replace the diff fluid before damage is done, if not already. Inspect the engine oil and trans fluid as well to see if water got into those areas as well. I'd look into the rear diff too.
there is a motorized actuator on the transfer case....insure that it is not jammed one way or the other and the actuating motor still turns~
this feller right here...make sure it engages properly~ http://www.monsterautoparts.com/chevrolet/chevy%20truck/tahoe/chevrolet_t ahoe_4x4_transfer_case_motor_switch.htm
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