4wd will not engage.

[sengland]

I have an 02 4runner w/ 61k. Today I tried to engage the 4wd but, when I pushed the 4wd button the indicator lights(green tires-yellow differential) on the dash just kept blinking and never engaged until it flashed 12-20 times and then when I tried to disengage the 4wd it started flashing again. I had to stop, turn off the engine, and restart the 4runner for it to stop. This problem continued multiple times and when the 4wd would engage there would be a "pop" from under the car.

[stir_fry_boy]

the "pop" is normal. Are you driving straight? Do the tires have relatively the same tread on them?
Are you driving it once in a while in 4wd to lube everything up?
Consider changing your diffs and transfer case oil to either redline or AMSOIL. Mine goes in and out SOOOO much better with AMSOIL in the txfer case.

[stir_fry_boy]

This is a good thread on Yotatech.com, I think there should be info on your 02'
4WD won't disengage on 99 4Runner LTD - YotaTech Forums